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Topology - Science topic

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This relationship has been known since 1937, based on a work by Pavel Alexandrov, however its application and theoretical and practical meaning is apparently not very widespread. Perhaps it is because of the simplicity of these spaces, none of them, except the trivial ones, are no more than T0 spaces. However, the current boom in data AI and other computational methods could make us think about its probable importance (and its relation to Algebraic Topology).
It would be interesting to know, for example, the relations of hypercube with the corresponding finite topological spaces.
Do you have any information on this?
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  • Finite topological spaces can be associated with simplicial complexes, which are central to algebraic topology. This allows for the computation of topological invariants, such as Betti numbers and Euler characteristics, using combinatorial methods.
  • Homotopy Theory: Finite spaces provide a discrete setting for studying homotopy theory. For example, the homotopy type of a finite space can be determined by its associated polyhedron, leading to insights into the classification of spaces.
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Even with very less wannier spread (nearly 1) band structure deviates a lot from DFT band. Please comment to reduce discrepancy .
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yes we can
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A physics experiment [1], driven on an expanding spin-orbit coupled Bose-Einstein condensate, suggested that a self-trapping effect band (explained in terms of the Peierls-Nabarro energy barrier) separates two dispersion domains characterized by a positive mass but a spin reversal. The self-trapping phenomenon was naturally explained by a negative effective mass related to a negative curvature of the underlying dispersion relation (as opposed to parabolic curvatures).
To better contextualise my question from a practical point of view, I will quote Wikipedia ( follow https://en.wikipedia.org/wiki/Spin_(physics) ): “Mathematically, quantum-mechanical spin states are described by ‘vector-like objects’ known as spinors. There are subtle differences between the behavior of spinors and vectors under coordinate rotations. For example, rotating a spin-1/2 particle by 360° does not bring it back to the same quantum state, but to the state with the opposite quantum phase; this is detectable, in principle, with interference experiments. To return the particle to its exact original state, one needs a 720° rotation (The Plate trick and Möbius strip give non-quantum analogies).
I appeal here to physicists in a spirit of free and friendly discussion.
  1. Khamehchi et al., “Negative-Mass Hydrodynamics in a Spin-Orbit–Coupled Bose-Einstein Condensate”, 2017 - https://www.researchgate.net/profile/Thomas-Busch/publication/311612111_Negative-Mass_Hydrodynamics_in_a_Spin-Orbit-Coupled_Bose-Einstein_Condensate/links/5a97b63845851535bcdee6fd/Negative-Mass-Hydrodynamics-in-a-Spin-Orbit-Coupled-Bose-Einstein-Condensate.pdf
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"[...] les composantes chirales du champ de Dirac: elles s'échangent
par parité et par conjugaison de charge, mais pas par renversement du
temps."
Extraits des sources bibliographiques :
"[...] the chiral components of the Dirac wave function; they are permuted under parity (P) and charge conjugacy (C) but not under time reversal (T)."
Excerpt from:
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I'm trying to explain organic molecule's adsorption onto activated carbon based on chemical parameters, and I found a good correlation between the adsorption amount and topological polar surface area (TPSA).
However, this parameter is used only to explain pharmaceutical absorption and not for different groups of organic molecules. Instead, electron density has been studied as a very important element in adsorption phenomena.
Can these two parameters be correlative? Does it make sense to consider adsorption and some pesticides TPSA, for example?
Any help would be significant to me.
Thanks.
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Thanks for the contribution Bello Ibraheem Qozeem Matej Babjak
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Which force field is better suited for these complexes?
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Thank you.
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Computational topology of solitons
The well-established research area of algebraic topology currently goes interdisciplinary with computer science in many directions. The Topological Data Analysis gives new opportunities in visualization for modeling and special mapping. A study on metrics used or simplicial complexes are reliable for future results in the area of mathematics. Today, the machine learning from one side is a tool for the analysis in topology optimization, topological persistence and optimal homology problems, from other side the topological features in machine learning are new area of research, topological layers in neural networks, topological autoencoders, and topological analysis for the evaluation of generative adversarial networks are in general aspects of topology machine learning. On practical point of view, the results in this area are important for solitary-like waves research, biomedical Image analysis, neuroscience, physics and many others. That gives us opportunity to establish and scale up an interdisciplinary team of researchers to apply for funding for fundamental science research in interdisciplinary field.
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Dear Dr. Galina Momcheva
I am a PhD candidate at the Department of Mathematics of the University of Rajshahi. My current research interest is Topological Data Analysis and Its Application which is quite parallel to the project you have mentioned here. I am working on this topic since 2021 and have completed 2 projects as a research assistant. Please visit my researchgate profile for a glance on my research outputs. Now-a-days, I am very interested in developing a TDA-based ML/DL model to introduce new framework for data analysis in different field of interests.
I have noticed that the job recruitment is currently closed. However, I am interested to continue my research as a postdoc fellow in a project similar to this. Please feel free to email me at mbshiraj@gmail.com.
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A problem for all the mathematicians in the world in the areas of Algebraic Topology and Topological Group theory and Automorphism groups of Riemann surfaces and Topological Groups and their Toplogical Genus g.
I am writng a paper in the above areas and one problem has kept me busy for six months now, which I thought of asking you all to see if there is a way to rich the answer I am looking for.
My problem:
Given the equation of a topological Riemann Surface in the following style and form:
F<W>:=GovaField(79);
P<X>:=PolynomialRing(F);
R<Y>:=PolynomialRing(P);
G<Y>:=
FunctionField((X^(13*m)*Y^(13*n) +X^13*n *Y^13*m)+
(X^13*k * Y^13*l +X^13*l *Y^13*k)+
(X^13*p + Y^13*p) -1);
Genus(G):= ?
Question for all Mathematician in these areas:
For what values of the unknown {m, n, k, l, p},
the value of the g = Genus(G):=21763?
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Reza,
I have a question. I recognize your rings except for "GovaField(79)". Is this the finite field over p=79? I notice the degree of polynomials (13) divides p-1.
Your goal of finding the genus sounds difficult especially since the object seems so complicated.
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For example, if I were to load a .pdb or .cif file to Avogadro or VESTA, is there a way to click on the carbon atoms next to oxygen atoms and label them "Ct" so that then when the coordinate data is exported the new tabulated .pdb has those carbon atoms' coordinate information followed by Ct as the label.
This would be pretty helpful for building molecular topologies in gromacs, amber and the like. I thank you in advance, for your attention.
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change the source code
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Hi all,
Please suggest how I need to optimize a small molecule to generate the topology file for the ligand to process it for Protein-Ligand MD simulations.
I have tried to balance the valency of the molecule, after which I have submitted the molecule to CGenff server, but the charge penalty and penalty scores were very high.
After which I have tried to optimize the molecule using Avogadro software. Using the output from Avogadro, I have resubmitted the molecule to CGenff server, after which the penalty score was even higher.
I have also tried PRODRG and ATB but the molecule was broken in case of PRODRG, while processing for MD. The molecule contains 1 chlorine atom, also attaching the warning suggested by ATB server.
Kindly suggest how can I process this molecule? I am really new to this work. Please suggest if I am processing it appropriately or not.
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did you find a solution for your problem?
If you did, can you explain it please
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There are numerous Ribe space constructions but ultimately they produce the same general object, a quasi-Banach topology on the direct sum of the real line R with the Banach space l_1 of absolutely summable sequences. In all constructions R and l_1 are algebraic complements but R is closed and not complemented topologically. Every such space is non-locally-convex and Rademacher type 1. However, some embed into Lp for 0<p<1 while others do not. Some versions are minimal which is equivalent to having no basic sequence. Since every subspace of Lp contains a basic sequence, these versions cannot embed into Lp and the versions embedding into Lp must contain a basic sequence. However, every version seems to have the property that the uncomplemented 1-dim. subspace R is a subspace of every inf-dim. closed subspace. Doesn't this mean every version fails to have a basic sequence? Thus, every version is minimal and no version embeds into Lp for any 0<p<1.
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Actually this is very subtle. Depending on the choice of quasi-linear function used to define the quasi-norm, you can get a space that embeds into Lp for all 0<p<1. Such space necessarily contains a basic sequence. However, with a different quasi-linear function, the space obtained may be minimal. For locally-bounded F-spaces this is equivalent to the lack of any basic sequences.
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Let X be a Banach space with the following properties.
(1) X embeds into every inf. dim. closed subspace.
(2) If T is a vector topology then T is a strictly weaker Hausdorff topology on a subspace
of X if and only if it is the subspace topology of a strictly weaker Hausdorff topology on X.
Question 1: Does (1) follow from (2)?
Question 2: If X is Reflexive, must it be a separable Hilbert space?
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Condition (1): Any of its closed infinite-dimensional subspaces can contain X.
Condition (2): For a vector topology T, it is the case if and only if it can be extended on all of X that T, the only weaker Hausdorff topology on a subspace of X is a strictly weaker T.
Question 1: Is it the case that (1) is a consequence of (2)?
Answer: No in a word, and in more words, condition (1) Is not a consequence of condition (2).
Proof:
Always define a connecting plane or union of spaces, this is what induction in geometry is all about or what PT is about.
On the contrary, about direct embeddings/inclusions onto infinite dimensional closed subspaces.
A counterexample exists: let us take p dimension in space of sequences for p≠2 with ℓp⊕ℓ2 representation.
Condition (1) is false, hence, it is not a topology in exploration that can be embedded into an infinite dimension.
However, (2) satisfy as every weaker topology practically extend to any space.
Condition (2) extend to radial B-space and it is expected to be implemented because such space radially extend to any dimension.
Question 2: Let X be a reflexive space: does it at every point must be equipped with a separable Hilbert space as its centre?
Answer: Yes, a separable Hilbert space is equipped as centre, but on assumptions that X is reflexive and X satisfies both conditions (1) and (2).
Proof: The above proof clearly indicates that (i) there must be certain separation, meaning X is enough to consider super reflexive.
Indications also suggest that such properties violate containment, similar to (ii) and X must contain Radon-Nikodym property.
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Hello everyone!
I'm calculating protein dimer structure in CNS-solve v1.21 using distance restraints obtained from solution NMR experiments.
There is an issue during calculation that most structures (not all) in the ensemble have two specific amino acids: one tyrosine and one phenilalanine broken like shown in the picture. The problem reproduces even after I remove all restraints associated with this amino acids.
I tried to review topology file, but did not find anything suspicious about these residues.
I would greatly appreciate if you could give me any hints on how to solve this problem.
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Moved project to cns_solve version 1.3, problem no longer occurred
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Hi all,
Thanks for taking the time to help me. I have generated a charged oligomer chain using acepype, as it is the only software I have been able to find to automatically parametrize using the OPLS-AA force field. However, the output file indicates that there are atoms that it could not define. I have attached the files for further clarity. Would it be enough to define these groups by hand, assigning them to the functional groups that suit them best in the topology file with this force field?
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When generating topology files with acpype (which uses Antechamber and GAFF primarily), encountering undefined atoms or residues when using the OPLS-AA force field is relatively common, especially if acpype cannot match certain groups with the correct parameters in its database. If your output file has unidentified atoms, manually assigning them in the topology file can work, especially if you have a clear understanding of the groups involved and the functional groups they resemble.
Here are some steps and best practices:
  1. Identify and Verify Groups: Look closely at the atoms flagged as undefined. Map these to corresponding functional groups in the OPLS-AA parameter set as accurately as possible. This step ensures that any substitutions you make align with OPLS-AA's parameterizations.
  2. Manual Parameterization: When defining these groups by hand, ensure consistency by consulting OPLS-AA documentation or related literature to confirm the compatibility of force constants, partial charges, and bond parameters with the oligomer’s structure. This manual assignment will involve:Assigning atomic charges and force field types. Ensuring bond, angle, and dihedral parameters align with functional group analogs in OPLS-AA.
  3. Topology File Updates: Modify the topology file by assigning missing parameters directly within it. This approach should be undertaken with caution, as small errors can destabilize simulations. Additionally, test the modified file by running a short minimization to verify stability before running full-scale simulations.
  4. Testing and Validation: Run validation tests, such as energy minimizations and short molecular dynamics simulations, to ensure that the assigned parameters result in stable configurations.
Alternatively, tools like LigParGen or ParamChem might be able to assist with parameterization using OPLS-AA, though these tools may have limitations on specific oligomer types.
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How is the topology of a closable topological subspace S related to the complement of this subspace in its closure, and of the complement to the S closure the X space?
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To know my opinion on this question, see my Research proposal
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A subset of a topological space is called delta-open if it is the intersection of
countably many open sets.
D. B. Gauld and others defined a topology on the set X=[0, +infinity[ by
using the sets A\cap [x, +infinity[ , where x is in X and A is a co-finite subset
of X as the basic open sets.
They stated that ever dense, delta-open subset of the space X is of the form
A cap [x, +infinity[ , where x is in X and A is a co-countable subset of X.
However, I have not been able to prove this statement, despite that they
considered it to be obvious. Therefore, I ask you to provide me a
reasonable proof.
Their statement is important. Namely, it can be used to prove that
Volterra spaces are genuine generalizations of Baire spaces.
Relevant references are:
1. D. Gauld et al, On Volterra spaces II, Ann. N. Y. Acad. Sci.
806 (1996), 169--173. ( Example 1.)
2. F. A. Ballone, Volterra Spaces, Dissertation, Youngstown State University,
2010, 74 pp. ( Example 5.3.1.)
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See the enclosed file. I hope that the proof is correct.
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If a string vibrates at 256 cycles per seconds then counting 256 cycles is the measure of 1 second. The number is real because it measures time and the number is arbitrary because it does not have to be 1 second that is used.
This establishes that the pitch is a point with the real number topology, right?
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Since I wrote this question I realized that frequency is not a velocity but a potential energy, which like 25 mph, is also defined on a time interval.
The string frequency is not a real valued function, it is a scalar output by a functional. The functional takes the equation of motion as input and outputs a number. The number is an extremal given by the calculus of variations. When the string is plucked, it quickly zeros in on the frequency with the lowest energy as a solution to the calculus of variations.
This is important in music theory because we want the frequencies on musical instruments to be algebraic numbers, not sine wave. That is, frequecy is real but constant and cannot change as long as the instrument is in tune.
This explains how the frequency is constant right up to the moment it stops. Velocity cannot go to zero at a point.
The frets on guitar are functionals that take the string tuning function as input and output the frequency.
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I have been seeing and following a lot of work on these topics, it even seems that there are more results on them than on the corresponding classical topics, particularly on general topology.
What could be the cause of such results?
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Dear Colleagues,
If U and E are fixed sets, A is a subset of E, and F is a function
of A to the power set of U , then F should be called a soft set
over U and E , instead of the pair (F, A).
Thus, since set-valued functions can be identified
vith relations, a soft set over U and E is actually a relation
on E to X. That is, a subset of the product set of E and U.
Therefore, several defininitions and theorems on soft sets,
consuming a lot of pages, are superfluous. Moreover, notations
and terminology can be simplified.
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Hello.
I am trying to parametrize a ligand using SwissParam. It generated me topology (.rtf) and parameter (.prm) files, but the topology file isn't working in Autopsf so I can't generate a .psf file for my future NAMD simulation.
Below is the topology file, mol2, and the prm. My assumption is that the ligand has atoms not supported by the CHARMM force field.
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Aarav Singh It's because the resname is not defined in the mol2 file.
save it into a pdb file with the resname as defined in the topology file (it's QE2 here) then you can be able to get the psf from VMD.
I've attached the pdb for your reference.
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i make a design topology of mixer For my graduation project working at 28 Ghz on cadence with UMC pdk and get this result
S(2,1) 3.5db
but when trying to make same topology with another pdk on ADS to make optimization i don't get any good results in addition there is some errors. How can i solve this problems ????
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Add the DC simulation palette. It is obvious if you use different PDKs, the results would be different. You can follow the warning message and do the required changes by going to the simulation setting.
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There is no doubt that the current young pure mathematicians question the applicability of many abstract theories enjoyed in pure math courses. It gets worse if an instructor is asked the application of a particular theory he tries to prove in the class that he himself does not know how it applies in real life.
Mathematicians now try much to get to the bottom of this inquiry. One has developed a topology on a nation with aim of making a nation a topological space: and . The question that comes in mind is: is it possible to develop a pure math theory that approximates the physical reality as that of espionage, domination, or alliance in a general topology context using Cantor or Zermelo-Frankael Set theory alone?
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The classical Nash Theorem, widely used in economics, political science, and many other fields, is fundamentally based on the Brouwer Fixed Point Theorem, which is a result in pure topology.
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The main website is broken and I can't find the topology dataset I want for my experiment.
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All topologies from the Topology Zoo are available there: http://www.topohub.org/
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I wanted to show membrane protein topology in 3-dimensional form with membrane intact. I wanted to show extracellular region, membrane region and intracellular region of protein in 3-d form. I have been using protter but it shows in 2D form only.
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For displaying membrane protein topology in three dimensions, open-source tools such as PyMOL, Chimaera, PymolMembrane, MembranePy, MDAnalysis, VMD, and ProLego are available. A well-liked programme for molecular visualisation, PyMOL has a number of plugins and tools for working with protein structures, including membrane proteins. Another tool is Chimaera, and PymolMembrane is a PyMOL plugin made especially for this use. A Python module called MembranePy gives users access to a variety of visualisation tools for producing 3D visualisations. A Python package for molecular dynamics simulations is called MDAnalysis. ProLego is an online platform where users can upload protein structures, while VMD is a tool for molecular visualisation.
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I have been running my phylogeny tree in MEGA X. My phylogeny tree doesn't seem to have any major differences between species in plain view, but the branches are becoming more clearly divided and each species looks to have major differences in topological view. What happened to my phylogeny tree?
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I suspect you are looking at the difference between a "cladogram" with meaningless branch lengths, and a phylogeny where branch lengths are proportional to the distances between the sequences.
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Hi!
Does anyone know if you can keep the different parts of an assembly separate after running topology optimization on it in Abaqus?
All three parts of my assembly merge to one after I optimize the assemply but I would like to export them separately to 3D print and test the assembly experimentally.
Thanks!!
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Ines Ortea Can you share your Abaqus model (.inp)?
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I have already tried AMBER and other force fields. The problem is with topology file creation. As there is no crystal structure or even a similar structure. So, I have to predict the structure using Ab initio modelling. In AMBER, the H++ server cannot process the model structure. Is there any alternative method for creating a topology file?
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Here is a similar topic from GROMACS forum so maybe you would find it useful - https://gromacs.bioexcel.eu/t/metal-ion-moves-away-from-the-enzyme-during-the-simulation/5036/2
Also maybe there is a sense to find paper contains similar MD protocols like this -
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Hello
I would like to know : In the context of photovoltaic systems, if it is essential to integrate diodes into modular series and parallel chopper topologies? What is the significance of this integration, and what are the advantages and disadvantages of adding diodes in these configurations?
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Thank you Vladimir for your advice. I understand that expediency is more appropriate than necessity in this context. I will also take cost into account to assess feasibility. This will help me better structure my analysis.
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The diagonal method is built assuming that, if two figure sequences like r = 0.a₁a₂a₃... and t = 0.b₁b₂b₃..., for some n satisfy the inequality aₙ ≠ bₙ, then r ≠ t. However, this is only true under the discrete topology.
Under the standard one, if r = 0.1000... and t = 0.0999..., then r = t although a₁ ≠ b₁.
There is an infinite set of rational numbers in [0, 1], each member of which can be denoted by two different figure sequences.
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The initial question in this thread is very simple. I summarize.
In the mathematical literature you can find the use of Cantor's diagonal method. This method is based on the following assumption.
If the figure sequences of two real numbers, r = 0.a₁a₂... and t = 0.b₁b₂..., for some index n, satisfy the inequality aₙ ≠ bₙ. then r ≠ t. Even my barber knows that 0.1000...= 0.09999…
Is such an elementary error admissible in the scientific literature?
I prefer proof from my barber, if it is based on logic, than the opinion of a great man.
Please, if you have any argument against the initial question, do not cite some great genius, I prefer, simply, logic.
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I am running a RNA ligand simulation on gromacs , i encountered a problem in which the number of coordinates in coordinate file (EM.gro, 2171) does not match topology (topol.top, 30886) file. PLease help me with this problem.
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thank you so much
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A TRANS-PRAGMATIC TRUTH PARADIGM
FOR SCIENCE, TECHNOLOGY,
AND PHILOSOPHY
Raphael Neelamkavil. Ph.D., Dr. phil.
1. OBLIGATION TO PRAGMATISM AS A NEGATIVE TRIGGER
My concept of universally real trigger-causation in all existents is philosophically and scientifically indebted to the most glaringly universal instances of the ‘effects only’, ‘use only’, ‘limited space’, ‘limited time’, ‘limited causal roots’ type of pragmatic bases of the functioning principles of most philosophical and scientific schools and disciplines and their effects on all aspects of life.
In spite of such effects, the majority of humanity, especially the scientific community – does not learn to bring about a radical re-definition of the pragmatically defined concept of attainable truth. This is the proof of the relevance of a re-formulation of the same by the science of philosophy and by scientific philosophy in the realization and growth of science, technology, etc.
Just within the pragmatic attitude lives and functions a big majority of the humanity. Specifically, the scientific community acts consciously by inhibiting wholesome ideas, actions, and changes in the usually pragmatic functioning of (1) every possible realm of knowledge, including the human project of thinking, feeling, curing, facilitating, etc. or (2) any other realms of life in any given environment and society.
The only given justification has been the urgency (1) to experience “the realizably” theoretical and practical effects of all ideas, actions, and changes as early as possible, (2) to have the awaited “long-term effects” at the earliest, (3) to have it in abundance “in the here-and-now”, etc.
Pragmatism has been the backbone of almost all, most basic and less basic, definitions, practical procedures, etc. in logic, mathematics, physical sciences, biological sciences, human sciences, etc. Pragmatism acquires constantly new definitions in history of science and philosophy.
By ‘pragmatism’ is meant not exactly and not only the philosophical school under this name. Of course, this philosophical school extols the effects-only and use-only theory beyond the emphasis it assigns to theoretical breadths and depths. In general, such emphasis plays an exaggerated role in determining the forms of access to what humanity needs in terms of life and truth. It is mainly the sciences that effectively inhibit any efforts beyond pragmatism.
The suggested new paradigm beyond pragmatism would be: The more the certainty and generality of the theoretical breadths and depths assured by the axiomatic foundations – the greater the truth of the specific, the individual, and the delineated results of such a founded philosophy and science within life and knowing.
I shall explain in other words the pragmatic state of the sciences. After all theoretical and experimental search, truth is being concluded to – albeit for a short time and with some or much assurance of probabilistic tenability – in a manner that is FULLY representative of the state of affairs sought to be represented.
The representation of an objectual process in a truth statement is taken to directly correspond or correspond enough to reality, when the theoretically antecedent instruments are universal enough to produce the knowledge about anything specific. But the antecedents are never universal enough, if the theoretical foundations are not broader than the theoretical grounding available in the positive sciences or formal sciences.
This sort of truth-representation is what knows, feels, cures, and facilitates life today, purportedly “in all respects”. Hence, pragmatism is merely be about the method of approaching truths and activities. But it has not been sufficiently about concluding something from a swarm of structures of theoretical generality and superiority, which should have worked in terms of theoretical and practical applicability in all possible specific cases available in any theory that is trans-pragmatic.
2. EXAMPLES OF OVEREMPHASIS ON PRAGMATISM
One example where the attitude of more general theoretical justification is missing is in the diverse theoretical constructs in physics. Anyone can characterise one of the many reasons as the blind and pragmatic acceptance, by many physicists, of the velocity of light as sacrosanct everywhere in the cosmos. In fact, we have been able to prove the velocity of light only with respect to our part of the universe, and have accepted it as the highest for all parts of the cosmos solely because we have not been able to detect one of higher value.
This is due to the overemphasis on pragmatism in science. Using such a limit velocity in science for technological success is a necessity, but insisting on it even in the broadest possible theoretical situations is cheap adherence. In this respect, the matter that none can accept is the way in which Einstein’s postulation of c as the reference velocity to measure and calculate other but lower velocities becomes accepted as the final proof of the very postulation!
What else is it but the consequence of strict pragmatism in the method and procedure of inquiry without enough antecedent theoretical broadening in the foundations, method, and procedure? This has debilitated science and philosophy of science for almost a century and a quarter. How to dispense with such pragmatism in science and philosophy?
Additionally, the declaration that the observed source-independence of luminal velocity is somehow a basis for accepting a background ether for luminal velocity to hinge upon, is again another instance of overmuch pragmatism in the method and procedure of theorization without restricting strict pragmatism to drawing conclusions.
A second example of strict pragmatism is the way in which some absolutely spherical geometries and their topologies were and are even now being used to geometrize the universe. They tend even to conclude from such a presupposition that the universe is spatially and temporally isotropic, and then tend to dispense with the effects of the locally causal temporal dimension on the universe.
Yet another example is the blind acceptance of the pragmatically probabilistic interpretation of quantum physics as the essence of all physics and of all physically existent reality, whereby most physicists attempt to accept a merely epistemic sort of causality in physical reality and call it “probabilistic causality”, and then start using it as if it were physical-ontological causality.
What we can understand (probabilistically, epistemically) need not be the same as how nature is out there! What in fact is the probabilistic causality that acts in physical processes with some parts of it being causal and other parts not causal or even acausal? Is not such a concept of causality a silly idea of causation based on epistemic determinism getting converted into ontological determinism, which then is converted into the actual nature of existent processes? The unnecessarily pragmatic ways of fixing scientific practices is the main reason behind it.
3. A TRANS-PRAGMATIC PARADIGM OF TRUTH
In preparing a short introduction to the following critical presentation of the aftermaths of pragmatism, let me put in gist the new paradigm that is necessitated here: (1) Truth is not merely a subject-object act. (2) Truth is not merely an act of tending towards. (3) Truth is much more an act of epochal finalizing of constant insertion of foundational breadths and depths in the state of affair / process being inquired into, based on the most universal of all conceptual foundations and driving them down onto the particular, but based fully and always on the foundations of the total in a mutually related context.
That is, strict pragmatism should be exercised only at the instance of concluding to the final, strictly contextual, statement and action, and that too under the provision of further constant inquiry and enhancement of the descriptions, conclusions, etc.
My contention concerning strict methodological pragmatism is that, although the pragmatic attitude has its rights over thought and practice, it (1) inevitably foregoes many fundamental (most broadly based on the totality of all existents) aspects of reality, environment, and life and, (2) in consequence, unbridles back onto the same reality, environment, and life the epistemically guided ontological aftermaths of the negligence of the said fundamental theoretical aspects and necessities of reality and of knowledge – and consequently of course onto life and the human ideal of comprehension of reality and life.
Hence, it is high time that philosophy and science eliminate as much as possible the defective, strictly pragmatic attitude from their foundations while safeguarding some of the necessary aspects of pragmatism merely when they create advantages via accessing conclusions and actions, without causing philosophical, scientific, and human-life tragedies.
4. SOME CONSEQUENCES OF PRAGMATISM ON SCIENCE AND LIFE
As there are countless disadvantageous aftermaths of pragmatism in knowledge and life, some of them may be cited in the following:
(1) International, national, and local politics purposefully manipulating natural resources, economies, societies, religions, and nations for power and wealth, even to the extent of impoverishing the majority of a continent or nation.
(2) National and international poverty alleviation programs and techniques which increase the rich-to-poor differences by perpetuating pragmatically charitable corruption in industrial, educational, health, and governmental ventures.
(3) Educational systems and methods becoming partially aimed at creating a vast majority of cheap labourers for the industry especially in poor nations, by fast-paced and obscurantist information-encrypting of sciences, humanities, and languages in educational institutions, without reference to the history of future-oriented achievements in discoveries, ideas, theories, events, programs, etc.
(4) Most media entities creating sensational partial truths as the short-time highest truths at the behest of politicians, industry, research & development, or at least against them, meant finally for easy financial gains and thereafter for practising political and scientific amnesia at the same truths.
(5) The pharma and health industry adopting and justifying as sacrosanct the mechanist-causalist manners of producing medicaments and treating patients – encouraged mainly by the successes of naturally necessitated urgency in such interventions – and producing chemical medicines so non-holistically (i.e., in ways that do not involve material interactions more minute and life-based than in chemical interactions) that the methods of production and treatment necessarily have more than intended side-effects creating ever more patients.
(6) Industries, technological companies, media entities, media producers, and a few nations specializing in hyperbolically creating and satisfying unhealthy and unessential psychological and physical needs and increasing easy production of commodities for quick-growth in economy, resulting in universal pollution of genes and life-forms.
(7) Constitutions of nations and justice-dispensation systems formulated in ways that normally foster or at least merely facilitate the exigencies of the powerful and rich and possibly get favoured in return.
(8) Governmental law-enforcement arms which work on old-fashioned and corruption-facilitating machinery and, from time to time, can milk the rich and powerful by way of protection of their pragmatic socio-economic attitudes.
(9) The more than two centuries of spread of chemical fertilizing methods of agriculture by blocking the spread of great natural cultivation methods and researches into them, callously titling the latter “unscientific”, and thereby chemically cluttering the whole cultivable and life-worthy earth.
(10) The millennia-old mammoth culinary science and eating culture that encourage tasty junk consumption at home and outside, successfully encouraging and perpetuating the enjoyment of quick pleasure from the one end of the tongue to the other.
(11) The way in which human beings, for millennia, exhaust and emaciate themselves in pursuit of quick joys, vastly unaware of the merely brain-based connotative nature of quick joys.
(12) The methods of finance acquisition and offspring-maintenance in families, societies, nations, and religions, oriented at self-perpetuation and attaining – for that same reason – nothing of it.
(13) Eco-compatibility efforts all over the nations by governments themselves, that help further industrialize under cover of grand holistic statements and schemes.
(14) Economic, educational, cultural, health, and other diverse forms of solution of problems of humanity, in which policy makers never go for the deepest roots of maladies: e.g., the real reason why people build houses on and cultivate (e.g., occupying and cultivating steep hill-sides, thus inundating the high ranges), is not merely craving, but the high rate of population growth, and yet no government acts in this direction ethically and democratically via education.
(15) The manner in which the very oppressed groups become much like the oppressor groups and indulge in pragmatic tactics against their own status, and consume the effects of such self-poisoning.
(16) The universal ignominy to what the experiences and the universal phenomenon of rational reflections of the old and dying are – including those of former scientists, technocrats, and scholars.
(17) The wide-spread technocratic and allopathic health-scientific methods of nipping all nature-infused living methods by blanket-terming them as unscientific.
(18) Religions’ millennia-old and continuing promise of a quick and miraculous transfer to a body-less state similar to that of a supposedly vacuous Absolute, instead of the more possible and reasonable “continued growth” of love-bodies as fully well caused by the same kind of growth during the lifetime of individuals and societies in imitation of an infinitely active love-bodied Source.
(19) A section of scientists and philosophers wilfully presupposing that anthropomorphized expressions and theologies based on them are the meaning of religion and spirituality, and basing their science, technology, medicine, and philosophy, etc. on notions that counteract these vicious concepts that should not have been the meaning of religion and spirituality.
(20) Some or many of those involved pragmatically in the above thought patterns and sciences trade their guns against supposed realities that do not exist in the sciences and in the world out there, thus beating in the air to kill some form of ideas that do not exist where they think them to exist.
The most suitable examples today in theoretical sciences are Russell, Wittgenstein, and many others in the early half of the 20thcentury, and Stephen Hawking, Richard Dawkins, Lawrence Krauss, and a host of others in the latter half of the 20th century and thereafter. The ways in which the likes of these experts have unquestioningly been using the already existing pragmatism in physics, cosmology, and philosophy is symbolic and emblematic of pragmatism as a cut-throat methodology in effect.
Technological examples are the ways in which Newton’s physics and mechanistic chemistry, biology, economics, etc. are being used today to facilitate money-flow into the industry by disregarding their health-related and environmental aftermaths.
Bibliography
(1) Gravitational Coalescence Paradox and Cosmogenetic Causality in Quantum Astrophysical Cosmology, 647 pp., Berlin, 2018.
(2) Physics without Metaphysics? Categories of Second Generation Scientific Ontology, 386 pp., Frankfurt, 2015.
(3) Causal Ubiquity in Quantum Physics: A Superluminal and Local-Causal Physical Ontology, 361 pp., Frankfurt, 2014.
(4) Essential Cosmology and Philosophy for All: Gravitational Coalescence Cosmology, 92 pp., KDP Amazon, 2022, 2nd Edition.
(5) Essenzielle Kosmologie und Philosophie für alle: Gravitational-Koaleszenz-Kosmologie, 104 pp., KDP Amazon, 2022, 1st Edition.
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Can somebody tell me how we worked with a topology-based routing protocol to alter it and under what limitations we did additional study in simulation?
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You can refer to the following articles that extensively studies the research gap on topology aware routing protocols for UAV/FANET. Thanks.
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While performing Protein-Ligand interaction in Gromacs version 2021 using the command line: gmx grompp -f ions.mdp -c solv.gro -p topol.top -o ions.tpr. I encountered this Fatal error: number of coordinates in coordinate file (solv.gro, 29336) does not match topology (topol.top, 54674).
I want to know how can I solve and correct this mismatch?
I am attaching both the files of topology (topol.top) and solv.gro
Thanks
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Nor Farrah Wahidah Ridzwan I am so very thankful for your time
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I tried to set .itp section after charmm.itp section but did not work
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The error message "Fatal error: Topology include file 'LIG.prm' not found" in GROMACS typically indicates that GROMACS is unable to locate the parameter (.prm) file for a ligand (LIG) during the addition of ions step. This error usually occurs when the topology file for the ligand is not specified or cannot be found in the working directory.
Here are some steps you can take to resolve this issue:
  1. Check File Location:Ensure that the 'LIG.prm' file is present in the working directory where you are running GROMACS. If the file is not in the current directory, provide the correct path or copy the file to the current directory.
  2. Specify Full Path in Topology File:If you have a separate topology file (.top), make sure the path to the ligand topology file is correctly specified within that file. Open the .top file and check if the 'LIG.prm' file is referenced with the correct path.
  3. Check Naming Conventions:Ensure that the ligand parameter file is named exactly as expected by GROMACS and that the file extension is correct (.prm). GROMACS may be looking for a file with a specific name, and deviations from that naming convention can lead to this error.
  4. Verify Topology File Contents:Check the contents of the ligand topology file ('LIG.prm'). Make sure it contains the necessary force field parameters and information for the ligand. If the file is incomplete or corrupted, GROMACS may not be able to read it properly.
  5. Update Force Field Files:Make sure that the force field files needed for your ligand are correctly installed. Check that the force field files and parameters for the ligand are available in the GROMACS installation directory or in the directory specified by the GMXLIB environment variable.
  6. Check GROMACS Version:Ensure that you are using a version of GROMACS that supports the force field and parameters used in your system. Different GROMACS versions may have different force field parameter requirements.
After checking and addressing these points, try running the GROMACS simulation again. If the issue persists, you may need to provide more specific information about your system setup, force field, and the contents of the topology and parameter files for further assistance.
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Two-dimensional Skyrmion topology can be quantized to form a quantum superposition of baryons and vibrational resonance states. (Wong, Stephen [2002]. "What exactly is a Skyrmion?". arXiv:hep-ph/0202250) This is quantum entanglement which is inextricably linked to topology. The fact that the topology only exists as a combined entity of the two photons suggests it could possibly combine not merely 2 photons but every photon in space-time (space AND time). George Yuri Rainich's 1925 paper pointed out similarities between gravitation and electromagnetism. So all the photons might be united with all the gravitons in spacetime.
Suppose we accept Albert Einstein's 1919 paper asking if gravitation (and electromagnetism) play a role in forming elementary particles. This paper is often regarded as outdated by discovery of the nuclear forces but my Opinions article in the journal "IPI Letters" says gravitational-electromagnetic interaction can produce the masses and quantum spins of the nuclear-force bosons, as well as of the Higgs boson. Accepting Einstein's 1919 paper means all mass in spacetime might combine with the united photons and gravitons - resulting in quantum gravity? And perhaps the two-dimensional topology can be identified with the Mobius strip in the way my article in IPI Letters details.
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Your question delves into a complex area of theoretical physics, intertwining concepts of Skyrmion topology, quantum entanglement, electromagnetism, gravitation, and quantum gravity. Let's break down the key points:
1. Skyrmion Topology and Quantum Superposition: Skyrmions, in the context of physics, refer to a type of topological soliton. A soliton is a self-reinforcing solitary wave that maintains its shape while moving at a constant speed. In two-dimensional Skyrmion topology, as you mentioned, there's a possibility of quantizing these structures to form quantum superpositions. This could theoretically involve entities like baryons (which are composite particles made of three quarks, such as protons and neutrons) and various vibrational resonance states.
2. Quantum Entanglement and Topology: Quantum entanglement is a phenomenon where particles become interconnected in such a way that the state of one particle instantly influences the state of the other, regardless of distance. The idea that entanglement is linked to topology would be highly speculative suggesting a deep-rooted connection between quantum mechanics and the mathematical study of shapes and spaces.
3. Photon-Graviton Unification Hypothesis: George Yuri Rainich's 1925 paper, along with Einstein's 1919 paper, hinted at a relationship between gravitation and electromagnetism. Your hypothesis takes this further, proposing that not just two photons, but potentially all photons (particles of light) in space-time could be united with gravitons (hypothetical particles associated with the force of gravity). This idea suggests a unification of forces and particles on a cosmic scale.
4. Gravitational-Electromagnetic Interaction and Elementary Particles: The concept that gravitational-electromagnetic interaction could account for the masses and spins of various bosons, including those related to the nuclear forces and the Higgs boson, is a significant extension of traditional models. Typically, these properties are explained through the Standard Model of particle physics, but your approach suggest a deeper and more fundamental connection. This will need to be unpacked further...
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Is there a connection between fixed point theory and algebric topology
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The Lefschetz (or Lefschetz-Hopf) Fixed-Point Theorem comes to mind.
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I am trying to create the topology of a Metalloprotein that contains copper as an essential cofactor. However, it is giving errors, in crystals and modeled structures. I'm very new to the DM field and I'm trying to learn it myself. Can someone help me? Below is the link with PDB of a my protein, and a crystal (other protein) which is already adequate for copper loads
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Handling metal ion is tricky in MD simulation, one possible approach is to link /convert the coordinate covalent bond of Cu ion to covalent bond, re-calculate the charges of interacting atoms/residues and create new amino acids reflecting the presence of Cu+, add them to amino acid library of force field.
The better thing is to look for someone who already publish the parameters of this set up. It will be lot easier for you to work with already tested parameters.
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Here by "surface" I mean a projective variety of dimension 2 (over an algebraically closed field k, as in Ch.1 of Hartshorne).
My question is:
Given a positive integer n >0, can we define a (possibly singular) surface S in n-dimensional projective space P^n, such that S does not admit an embedding into any P^m for m < n ?
That is, I am asking for a constructive proof, an effective algorithm taking as input n, that generates the set of homogenous polynomials defining such a surface.
How does this relate to the number and degrees of the homogenous polynomials required to define S ?
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Unless you are directly interested in number theory, does it make much sense to do algebraic geometry independently of complex analytic geometry and complex analysis in several variables ?
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There are several known contributions of Topology to ML.
But: what has been the contributions of ML to the research on General Topology, and particularly to Finite Topological Spaces? Do you have any information of this regard?
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Otherwise, how to solve problems in General Topology (proving theorems, or supporting the prove, obtaining open or close systems of subsets, determining open basis, etc) by application of ML techniques or its theoretical principal (in that last case it looks to be some kind of recursive application, given the heavy dependence of ML methods on metrical space properties considerations).
It's supposed most of those methods or approach are related to formalization of real world situations, by means of reducing the complexity of analyzed space.
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I am working on molecular docking and dynamic simulation of protein-ligand complex, and the complex generated MD.xtc file of 4.3 gb which I am unable to open in UCSF Chimera through MD movie option. I know that limited RAM of my system is creating this issue, but is there any other way to do it.
I also found that spliting trajectory file helps, but I am getting the following error (Screenshot 2023-11-27 13-31-13.png) while entering MD.tpr and MD.xtc in MD movie Gromacs option. Which I know is because the topology file is not splited like the trajectory file. So, how to rectify this issue, if there's no other way to work around.?
I am using Ubuntu OS, with 8gb ram, 2gb graphics 1650.
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It appears that you are working with big MD trajectory files, and the visual aids are not working properly due to RAM constraints. Trajectory file splitting is a workable solution, but it necessitates managing topology and trajectory files carefully. Here's how to use GROMACS to manage big trajectory files step-by-step:
Splitting Trajectory Files:
  1. Splitting Trajectory:Use the trjconv tool in GROMACS to split your trajectory file into smaller chunks. Example: gmx trjconv -f MD.xtc -s MD.tpr -o traj_part1.xtc -b <start_frame> -e <end_frame> -skip <skip_frames>
2 Generate New Topology:
  • When you split the trajectory, you need to create a new topology file for each segment. Use the original topology file (MD.tpr) for each segment;
  • gmx grompp -f md.mdp -c traj_part1.gro -p topol.top -o md_part1.tpr
Repeat for Each Segment:
  • Repeat the above steps for each segment of the trajectory.
Create MD Movie from Segmented Trajectories:
Now that you have segmented trajectory and topology files, you can try creating an MD movie for each segment and then concatenate them.
Create MD Movie for Each Segment:
  • Use GROMACS to create MD movies for each segmented trajectory:
  • gmx mdmat -f traj_part1.xtc -s md_part1.tpr -nice 0 -o mdmovie_part1.xpm
Concatenate MD Movies:
  • After creating MD movies for each segment, you can use a tool like convert from ImageMagick or ffmpeg to concatenate individual movies into a single movie:
  • convert mdmovie_part1.xpm mdmovie_part2.xpm ... mdmovie_final.gif
Visualization:
  • Finally, you can use a lightweight visualization tool, such as VMD, PyMOL, or UCSF Chimera, to open and visualize the final concatenated MD movie.
Note:
  • Ensure that the split trajectories have proper continuity (overlapping frames between segments) to avoid artifacts during concatenation.
This approach helps in dealing with large trajectory files and limited system resources. Adjust the parameters like start_frame, end_frame, and skip_frames according to your requirements and system limitations.
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Q=1: How can plot 3D graphs for topological indices by using Mathematica software??
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Plz send any coding for 3D mash graph related to attached sample graphs.
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Certainly! To create 3D mesh plots for topological indices using Mathematica, you can use the ListPlot3D or ListDensityPlot3D functions. Below is an example of how you might create a 3D mesh plot for a set of data points.
Let's assume you have a dataset in the form of {{x1, y1, z1}, {x2, y2, z2}, ...} representing the topological indices. Here's a simple example:
(* Sample data *)
data = {{1, 1, 5}, {2, 1, 8}, {3, 1, 6}, {1, 2, 4}, {2, 2, 7}, {3, 2, 9}, {1, 3, 3}, {2, 3, 6}, {3, 3, 8}};
(* Create a 3D mesh plot *)
ListPlot3D[data, MeshFunctions -> {#3 &}, MeshStyle -> {{Thick, Red}}, BoxRatios -> {1, 1, 1}, AxesLabel -> {"X", "Y", "Z"}, PlotRange -> All]
In this example, {#3 &} specifies that the mesh should be based on the z-values of the data. MeshStyle -> {{Thick, Red}} sets the style of the mesh to be thick and red. You can customize the styling and appearance according to your preferences.
This is a basic example, and you may need to adapt it to your specific dataset and requirements. If you have specific data or a particular topological index you want to plot,
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I would like to perform a shape optimization on a topology optimized component without exporting and importing the part as .stl, since in that way I loose all the properties, the loads and the BC. Please, is there any chance to to this?
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The capability to directly export the optimized geometry with associated boundary conditions and loads might depend on the version of ABAQUS and the specific procedures it supports.ANSYS might have specific features that streamline this process,
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I've been wondering because the definition of an eta-open set is if A ⊆ int(cl(int(A))) U cl(int(A)). While the semi-open set is if A ⊆ cl(int(A)). So, if int(cl(int(A))) just a subset of cl(int(A)), then int(cl(int(A))) U cl(int(A)) = cl(int(A)). This implies that an eta-open set is equivalent to a semi-open set. Can anyone enlighten me with this? because I've looking for examples that make these two sets not equivalent and still nothing found yet.
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If M is a subset of a topological space X , then int(M)⊆M⊆cl(M), and this property clears everything up!
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F(X,Y)= set of all functions from a topological space X to other space Y.
C(X,Y)= set of all continuous functions from a topological space X to other space Y
Compact open and compact convergence topology are comparable, if Yes then which one is finer on F(X,Y) (not on C(X,Y))
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Sir not for set of continuous functions
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Will it be a Majorana mode? But, Majorana modes are typically characterized by their strong localization at one end. If an edge mode is not strongly localized at one end and extends significantly along the other edge, could be an ordinary edge state or a different type of topological mode?
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Thank you for answering. Juan Weisz Sir, you are right. I am seeing these edge states in superconductor. They are in pairs but overlapping each other at both the edges. While I expected one edge state at one edge and the other edge state at the other edge.
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I am working on topology optimization using the parametric level set method. Regardless of the methodology, I thought it might be a generic problem in Topology optimization with which many researchers in the field have faced. The problem is that I cannot achieve smooth boundaries even though I am using the level-set method to produce smooth boundaries. I am using two different grids and meshes for the mechanical and the level-set domains. I thought I needed to increase the number of Finite elements from 350 to 1000, but nothing changed, you can see it from the bottom right figure. Nor did increasing the number of grid cells in the level set domain improve my result.
Thank you in advance for your help.
Best regards,
Farzad
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Dear Richard,
Thank you for your comment. I have actually tried different regularization methods. I have also made the objective function dimensionless in order to be sure of everything. However, none of the above strategies has led to a reliable solution. Thank you anyway for taking the time.
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Can anyone tell me how to draw or consider the arbitrary/ reference line in Wilson charge centre (WCC) along momentum space plots to predict whether the material is topological insulator or not.
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Hello dear Rati Ray Banik
As you write above it is just an arbitrary/ reference line, and you can put them anywhere, but before that you should make a good analyze of your results, I mean you first search if there is a Wilson charge centre that can intersect this line an odd time (topological insulators) if no you can draw it anywhere.
Good luck
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Are the oil-water partition efficient (logP) and Topological polar surface area (TPSA) of energetic compounds related to their molecular stability? How do these parameters relate to the molecular structure?
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According to our limited understanding and practical experience, the connection between TPSA and thermal stability is not significant.
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Generally, a topology tau on a set X is defined considering the following three axioms:
1. The whole set X and empty sets are in topology tau.
2. Arbitrary union of any collection of open sets of tau is in tau.
3. Finite intersection of any collection of open sets of tau is in tau.
Is it possible to construct a topology tau on X without considering first axiom?
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of course, no, because this is a first condition in definition of topology. In this case you make another structure and depending to you to named.
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To study the topology of the MOF crystals
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this is a great one and have a free verision for non commercial use. if you want files, templates or papers. you are free to contact me
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I am writing to seek assistance on a matter related to n2t file generation. I am using GROMACS and charmm36 force field in my work. I am covalently attaching a short polymer(poly-peptide) to a nanosheet with the carbonyl carbon of the polymer attached to the nitrogen of the nanosheet I obtained the parameter(itp file) for the polypeptide from CGENFF then added the corresponding atom types and charges from the itp to my n2t file the monomer of the poly-peptide is histidine and it’s itp file has various hydrogen atom type along with carbon types with different charges I have added them all in the n2t file in the same sequence as in the itp since most these atom types are attached to carbon when topology is created using x2top wrong type of carbon and consequently wrong charge is assigned to the atom of my structure. I want you to note the hydrogen types as well as the nitrogen type NG2R51 in the topology file at line 134 it is supposed to be a NG2S1 nitrogen type with a -0.555 charge. There are many other atoms whose atom type was supposed to be different. How can I obtain correct topology.I am attaching the itp file(plh.itp) along with the ss of topology and n2t file. Any guidance or pointers would be of immense help. Thank you for your time.
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Thank you very much for your suggestion, but as per my limited knowledge swissparam is appropriate for small molecule and would generate wrong atom types for atoms in the nanosheet.
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Are there any publications on the topological properties of nonstoichiometry loci - in general and, in particular, in intermetallic compounds?
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It can be assumed that nonstoichiometric zones of different nature can serve as sources of oscillations that transform the main stoichiometric mass of the crystalline material into a time crystal and thereby induce the generation of coherent radiation in accordance with the mechanisms described in the following articles:
1. Lyubarov M. et al. Amplified emission and lasing in photonic time crystals //Science377,425–428(2022) https://www.science.org/doi/epdf/10.1126/science.abo3324
2. Li H. et al. Stationary Charge Radiation in Anisotropic Photonic Time Crystals // Phys. Rev. Lett. 130, 093803 – Published 3 March 2023.- https://doi.org/10.1103/PhysRevLett.130.093803
This, in particular, may be the real physical mechanism of lithotherapy.
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Let (X, tau, I) be an ideal topology I ask:
wThe product of this topology itself is ideal topology or not?
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What you think abiut product case up to IxI
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Hi.
I am trying to create ligand topology and parameter files using SwissParam webserver. I followed all the steps to create the .mol2 file available in SwissParam page: https://www.swissparam.ch/SwissParam_mol2_file.html.
But this error keeps on coming:
Unfortunately, topology and parameters were not successfully generated for LIG.mol2. A failure report can be found below. Failure report: Possible problem with molecular topology in LIG.mol2. SwissParam will try to reconstruct the topology from coordinates only. Topology and parameters were NOT generated. Please check the validity of your molecule. - Are all hydrogens present in the mol2 file? - Is the mol2 file correct? Please, read "How to obtain a correct mol2 file?" in the www.swissparam.ch website.
For reference, I am providing my ligand.mol2 file and lig_fix.mol2 which I have created for performing protein-ligand simulation using Gromacs and CHarmm27 forcefield.
Please help me solve this query.
Thank you for consideration.
Alvea Tasneem
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Ajit Kumar Singh I am using CHARMM27 forcefield.
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I have been using PRODRG for small molecules topology for years, but now I can't access it, I have emailed its developers but couldn't get any response. I want to use Gromacs forcefield, so I have only 2 options, one is ATB which is not free for new molecules, and another one was PRODRG. Kindly give me suggestions if you know any other way. I have tried Swissparam and switched to Charmm ff but it also didn't work and gave me errors with LJ and at the energy minimization step.
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Usha Kantiwal been waiting for months. I think they have discontinued it. btw i switched to OPLS.
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I am starting a new area of research that is Algebraic topology. Kindly suggest some latest problems and related publications
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  1. "Simplicial Complexes and Homology Spheres" by Jeff Cheeger and Michael Gromov (1985)This article explores the relationship between simplicial complexes and homology spheres, which are important objects in algebraic topology. It introduces key concepts and provides insights into the combinatorial and topological properties of simplicial complexes.
  2. "Cohomology of Groups" by Daniel Quillen (1968)Quillen's article focuses on group cohomology, which is a powerful tool in algebraic topology. It provides an accessible introduction to the subject, presenting the foundations and basic techniques of group cohomology.
  3. "Euler Characteristic of Discrete Groups and Finite Buildings" by Pierre-Emmanuel Caprace and Bruno Duchesne (2012)This article investigates the Euler characteristic of certain classes of discrete groups and finite buildings. It discusses the connection between algebraic topology and group theory, offering a deeper understanding of both fields.
  4. "Singularities of Smooth Maps and the Whitney Conditions" by Hassler Whitney (1936)Whitney's seminal article establishes foundational results in the theory of singularities of smooth maps. It introduces the concept of Whitney conditions and provides insights into the structure of singularities, making it a classic in algebraic topology.
  5. "Homotopy Groups of Spheres" by Michael Hopkins, Alexei A. Ananyevskiy, and Nitu Kitchloo (2021)This recent article examines the homotopy groups of spheres, a fundamental topic in algebraic topology. It presents a comprehensive survey of the state of knowledge about these groups, with a focus on recent developments and open questions.
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I am having an issue regarding Phosphatidic acid topology generation for Gromacs 5.1.5 simulation. I would like to study the protein-ligand dynamics. Kindly help
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I'll try at my end if you can sahre the structure of protein and smiles for your phosphatidic acid Tanusree Mookherjee
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After running this step to create ligand topology for molecular dynamic simulation protein-ligand complex:
python3 cgenff_charmm2gmx_py3_nx2.py ligand ligand_fix.mol2 ligand.str charmm36-jul2022.ff
It showed some tracebacks and import error:
ImportError: cannot import name 'gcd' from 'fractions' (/usr/lib/python3.10/fractions.py)
Does anybody know how to fix this problem in Ubuntu with python3.10 version?
#gromacs #topology #moleculardynamics
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I have python 3.5.2, networkx 2.3 and numpy-1.25.0 all installed, the error persists, now i get the message
File "cgenff_charmm2gmx_py3_nx2.py", line 53, in <module>
import numpy as np
ImportError: No module named 'numpy'
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I tried to generate charmm36 topology and parameter files for copper ions on laccase enzyme but it presents an error that says "No residue in CHARMM forcefield". So I've tried CSML Search to parameterize ligand FF using PDB coordinates but the erros persists.
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Check the file .../charmm36.ff/ions.rtp to find out the exact residue name of copper ion.
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I am new to amber any trying to use xleap to make a tetrapeptide tuftsin. After solvation with TIP3PBox 14.0 iso, when I try to save the inpcrd and prmtop file using command
saveamberparm foo tuftsin.inpcrd tuftsin.prmtop
it gives following message
Checking Unit.
WARNING: There is a bond of 3.610664 angstroms between:
------- .R<WAT 886>.A<H1 2> and .R<WAT 886>.A<O 1>
WARNING: There is a bond of 4.162462 angstroms between:
------- .R<WAT 886>.A<H2 3> and .R<WAT 886>.A<H1 2>
WARNING: The unperturbed charge of the unit: 2.000000 is not zero.
-- ignoring the warnings.
Building topology.
Building atom parameters.
Building bond parameters.
Building angle parameters.
Building proper torsion parameters.
Building improper torsion parameters.
total 11 improper torsions applied
Building H-Bond parameters.
Incorporating Non-Bonded adjustments.
Not Marking per-residue atom chain types.
Marking per-residue atom chain types.
(Residues lacking connect0/connect1 -
these don't have chain types marked:
res total affected
CARG 1
I am not getting how to solve this error message.
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Did you able to solve this problem ?
I got the error also
The unperturbed charge of the unit (-2.000000) is not zero.
[DEBUG ] FATAL: Atom .R<CGLN 91>.A<O2 20> does not have a type.
[DEBUG ] FATAL: Atom .R<CGLN 91>.A<O1 19> does not have a type.
Please help me.
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I want to simulate a grid-road topology (organized streets) with vehicles generate traffic to Road Side Unit (RSUs). Also, if I need to ramp up quickly to 100 or 200 vehicles how can I do that?
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The simplest way to do this is to use a File-based approach; this approach does not require any modifications to NetSim code. Your program in MATLAB should write the device position with respect to time in a text file. The format is explained in https://www.tetcos.com/help/v13.3/Technology-Libraries/MANETs.html#file_based_mobility_model
In the devices which you wish to move per MATLAB data, set the mobility model to File-Based Mobility and update the Mobility CSV file with input generated from MATLAB in NetSim's mobility file format. The mobility file is common for all devices in the network. Hence, if you want to introduce mobility in multiple nodes based on data from MATLAB all this information can be put together in the same mobility CSV file which NetSim will read at the simulation start.
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I am seeking a pdf or doc file . #Molecular_Dynamic_Simulation #Gromacs #Protein-Protein MDS Hey, I am working on a project where MD simulation is needed for protein-protein interaction in a dynamic nature. I have previous experience of doing protein-ligand MD simulation from Lemkul's tutorial. Now I am facing a few problems, including 1. In the protein-ligand case, first build the protein topology and then the ligand's one. In the ligand topology generation section—another server used to obtain itp files and introduce them to the protein topology file— In protein-protein MDS, what should we do? Where we get the topology of another protein.
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1) To create an index file to calculate RMSD, type the following commands and press enter:
1> gmx make_ndx -f md.gro -o chain_CA.ndx
2> splitch 3
3> q
4> gmx rms -f md.xtc -s md.tpr -n chain_CA.ndx -o rmsd_chain_A.xvg
Select chain A in index numbers
Select chain A in index numbers
5> gmx rms -f md.xtc -s md.tpr -n chain_CA.ndx -o rmsd_chain_B.xvg
Select chain B in index numbers
Select chain B in index numbers
2) To create an index file to calculate RMSF, type the following commands and press enter:
1> gmx make_ndx -f md.gro -o chain.ndx
2> splitch 1
3> q
4> gmx rmsf -f md.xtc -s md.tpr -n chain.ndx -o rmsf_chainA.xvg
Select chain A in index numbers
5> gmx rmsf -f md.xtc -s md.tpr -n chain.ndx -o rmsf_chainB.xvg
Select chain B in index numbers
If you need help, upload the .gro file of the simulation output, so I can guide you.
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12
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NEAT (Neuroevolution of Augmenting Topologies) is a genetic algorithm that combines neuroevolution and the evolution of neural network topologies. It was introduced by Kenneth O. Stanley and Risto Miikkulainen in 2002 as a method for evolving artificial neural networks (ANNs) with minimal human intervention.
NEAT addresses the challenge of designing neural network architectures by allowing the evolution of both the weights and the structure of the network. Traditional neuroevolution techniques typically use fixed neural network topologies and only evolve the weights of the connections. In NEAT, however, the topology of the network can change and evolve over time.
The NEAT algorithm begins with a population of randomly generated small networks with minimal structure. These initial networks are often referred to as "organisms." Each organism's neural network is initially composed of input nodes, output nodes, and no connections. During the evolutionary process, NEAT allows the networks to evolve by adding or removing nodes and connections.
The evolution in NEAT occurs through a process of selection, mutation, and crossover. The fitness of each organism is evaluated based on its performance in solving a specific task or problem. Organisms with higher fitness are more likely to be selected for reproduction.
Mutation plays a crucial role in NEAT. It introduces innovation by adding new nodes and connections to the networks. This allows the networks to grow in complexity over time. Mutation also affects the weights of the connections to refine the network's behavior.
Crossover, which is the genetic process of combining genetic material from two parents, is also utilized in NEAT. During crossover, matching genes (connections with the same historical origin) are inherited from the parents, while disjoint and excess genes are inherited randomly from one of the parents.
The novelty of NEAT lies in its ability to evolve both the structure and weights of neural networks simultaneously. This enables the algorithm to discover complex network topologies that can solve various tasks effectively.
NEAT has been applied to a wide range of problem domains, including control tasks, game playing, and robotics. It has demonstrated the ability to evolve neural networks that outperform manually designed architectures in certain scenarios and has contributed to the field of neuroevolution.
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If we want to calculate several M-polynomials which method is the most suitable.
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Stardog database
Stardog offers the most advanced graph data virtualization and high performance graph database.
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I ran gromacs with command: grompp -f ions.mdp -c protein a_solv.gro -p topol.top -o ions.tpr. and yielded a Fatal error:
number of coordinates in coordinate file (solv.gro, 57741)
does not match topology (topol.top, 57742)
how to correct the match of protein a.gro and topol.top file?
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Vikas Yadav try this workflow easy and reproducible for simulation
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While I was trying to generate ligand topology using CGENFF, the penalty score exceeded 50 (parameter penalty 141; charge penalty= 56.475). how do I reparameterize to obtain acceptable penalty score range?
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Hi via FFParam or ffTK via VMD, however, both do not function via Mac, if anyone knows a similar software thats Mac compatible please advise, thanks :)
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The fixed point property is a fundamental concept in topology and has been extensively studied in various contexts. However, there are still several open problems related to the fixed point property. There are many other interesting questions and directions of research in this area.
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Dear Deuri,
I would be of some interest to establish some particular fixed point
theorems for the postman, radial and river metrics and dome of
their common generalizations.
My enclosed paper was refused by I. A. Rus, at the journal
Fixed Point Theory, with the sentence that it is not connected
with fixed points.
With best regards,
Arpad Szaz
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I am trying to find out the topological hall effect for my system of study. I currently have no idea about the process and what software packages to use. I know that we can find the anomalous hall effect (AHE) using the Wannier90 package. Any suggestions regarding this will be greatly appreciated.
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Thank you for your answer. Can you please suggest which computational tools are used to predict THE. I use VASP for DFT calculation. @Sunita
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I want to perform MD simulation on a protein that contains water molecules in PDB what forcefield parameters (topology/ parameter ) files should one use ?
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Still, your goal is vague to me, as the water model will treat both types of water with the same parameters.
I never used NAMD, so I can not comment in detail.
The angle parameters of CT1 and C should be provided by the force field you are using. IF the NAMD is unable to find it, you should check the FF files for the naming convention (maybe you need to mention that this is the terminal residue).
Regarding HT, did you add hydrogens to your crystal water? If yes, then check the naming convention of how the water model (you are using) names H-atoms in the water molecule. If not, then what HT refers to; hydrogen or oxygen (I am guessing, it should be Hydrogen), I don't have any more ideas left to share.
Good luck
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Hello everyone,
While performing MD simulations of protein - ligand complex, at the adding ions stage I am facing an error :
Fatal error:
Syntax error - File UNK_fix.itp, line 7
Last line read:
'[ atomtypes ] '
Invalid order for directive atomtypes
Well, since I've used Swissparam to write the topology file of the ligand (UNK_fix.gro) which usually uses CHARMM all atom forcefield and the protein topology I've written with the charmm36-2019.ff. Can this be a reason that I'm facing the above error?
I've also referred to other options like #include statements which I suppose are correct and the editing in topology is all done right. For reference:
; Include Position restraint file
#ifdef POSRES
#include "posre.itp"
#endif
; Include ligand topology
#include "UNK_fix.itp"
; Include water topology
#include "./charmm36-mar2019.ff/tip3p.itp"
#ifdef POSRES_WATER
; Position restraint for each water oxygen
[ position_restraints ]
; i funct fcx fcy fcz
1 1 1000 1000 1000
#endif
; Include topology for ions
#include "./charmm36-mar2019.ff/ions.itp"
[ system ]
; Name
Protein in water
[ molecules ]
; Compound #mols
Protein 1
UNK 1
SOL 24553
So, please guide me through any other suggestions which may correct this error.
Thank you in advance!
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Divya Jhinjharia, Thanks for your reply
Hope this will work for me
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I want to use cpptraj for some analysis but I need to convert my topology and trajectory files from Gromacs xtc, tpr format to Amber nc and parm formats. Could you please let me know how can I convert topology and trajectory files from Gromacs to Amber?
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Dear colleague Ekrem Yaşar
I think this link may help you:
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How to prepare topology file for coordination (complex) compounds. Topology files for organic ligand molecules can be obtained using online servers such as SwissParam and etc. How to prepare a topology file for a metal-containing ligand?
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I think there's no standard force field generator for metal-containing ligands. The best option is to use already developed force field parameters which is in line with experimental observations.
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gmx grompp -f ions.mdp -c solv.gro -p topol.top -o ions.tpr
Fatal error: number of coordinates in coordinate file (solv.gro, 198459)             does not match topology (topol.top, 198458)
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Dear Stuti Ghosh
The error message you are receiving indicates that there is a mismatch between the number of atoms or coordinates in your coordinate file ("solv.gro") and the number of atoms or coordinates in your topology file ("topol.top").
One possible explanation for this error is that there is a missing atom or residue in one of the files, which can cause the number of atoms to be mismatched. You should carefully check your files and make sure that they are both complete and consistent with each other.
Another possibility is that there is a formatting issue or a mismatch in the atom numbering between the two files. You should ensure that the atom numbering in the coordinate file matches the atom numbering in the topology file, and that both files are formatted correctly.
If you are unable to identify and fix the issue, you may want to try generating new coordinate and topology files, or seek assistance from the GROMACS user community or support team at https://gromacs.bioexcel.eu/
Best,
Satyendra
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Hi everyone,
I'm trying to optimize a very simple steel element (see figure) with a cyclic load applied in the two red regions. The settings are the standard ones (minimize strain energy, final volume 30%) However, after 6 cycles, the optimization process plot shows a flat curve and the result confirms that something has gone wrong. How can I solve the problem?
many thanks in advance
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Ivan Panzera Can you share your Abaqus model (.inp)?
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In fact, the phase will affect the amplitude distribution. For example, the OAM phase will cause the amplitude center to produce a small circle with an intensity of 0, and it will become larger as the topological value of the phase increases.
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In the case of an orbital angular momentum (OAM) beam, the amplitude of the beam is zero at the centre of the beam because the phase is undefined at the centre. This is a property of the beam, and independent of how it is generated. It is not generally true that the phase of the beam will affect the amplitude distribution.
You are probably thinking of a nematic liquid crystal spatial light modulator (SLM), which can modulate phase when set up in one configuration. If you alter the position of the polarisers around the nematic SLM it can actually modulate amplitude though, or a mixture of amplitude and phase, or even polarisation. You should be aware that there are other SLMs out there, including ferroelectric liquid crystal SLMs, digital micromirror devices and deformable mirrors. Crucially, it is not currently possible to do full amplitude and phase modulation.
There are are a number of ways to get around this. Typically, an optical setup is combined with an algorithm to give a solution. The optical setup performs some transform operation on the light field in the SLM plane. For example, a lens may be used to obtain a Fourier transform of the light field in the SLM plane. An algorithm is then used to determine what hologram should be displayed on the SLM to give the desired amplitude and phase profile after the transform operation.
Some solutions that have been implemented include:
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I am asking if such a hypothetical particle can effectively formerly described by mathematics as a non-Euclidean space object having more than three normal spatial dimensions and at normal time thus speed no more than c.
Ultimately, I'm asking if hypothetical superluminous phenomena can be formerly translated as extra dimensions and vice versa.
For example, can Hilbert space describe superluminous phenomena?
My interest is because I am intrigued by the idea that extra dimensions could be possible apparent effects caused by possible physical superluminous quanta phenomena in our normal three-spatial dimensions space.
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Perhaps an idea might be to express spatial dimensions as complex numbers.
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Hi everyone,
I work on Abaqus for a project and I want to optmise a part (topoogy + shape). I created the model an ran the topology optimisation. Now I want to extract the result geometry to make some shape optimisation. Is it possible to make it directly from Abaqus or with a Pyhton script or do I need to convert it in a CAD software ?
Thank for your help
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It is not required to extract the topology optimized configuration from ABAQUS and the following shape optimization process can easily be completed. But whenever it is necessary to investigate the optimized configuration at the last design cycle by another software such as AUTOCAD, it can be done following the steps in the attached figures.
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I'm having trouble doing network analysis due to topological errors. I am using ArcGis software.
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I'm not aware of any specific studies that have been conducted on the topic of fixing topological errors by writing code. However, there may be research in the fields of computer science, geospatial data analysis, or topological data analysis that address this topic. It might be helpful to search for relevant literature or to consult with experts in these fields to learn more about this topic.
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WARNING: topology has 41102 atoms, whereas trajectory has 3597
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I just read the article in "Australian Science Illustrated" about supersonic planes breaking the sound barrier and it gave me a very interesting thought that's related to an article I had published in a science journal last month. My article's called
"Riemann hypothesis supports topological propulsion and faster-than-light travel through space-time"
(10) (PDF) Riemann Hypothesis Supports Topological Propulsion and Faster-than-light Travel Through Space-time (researchgate.net)
and it was inspired by another article in "Cosmos" magazine (I started subscribing to Cosmos at the same time I subscribed to Science Illustrated).
SI's piece about the sound barrier says, "Sound waves in front of the plane become so compressed that they join together to form a shock wave."
My interesting thought is, "My paper builds on a 1919 paper by Einstein called "Do gravitational fields play an essential role in the structure of elementary particles?" Matter associated with the UFO becomes so compressed that the 3rd dimension can vanish from the parallelogram describing how gravitational and electromagnetic waves produce mass (Figure 2). This causes the top and bottom of the parallelogram to join together and form friction between the opposing movements of gravitation's gravitons and electromagnetism's photons. Their interaction is described using General Relativity's refraction of starlight passing the Sun and biology's "lock and key" mechanism where chemicals attach to receptors of the correct shape. Joining of the parallelogram's top and bottom also creates the single surface of the Mobius strip which my article says is a fundamental building block of space-time and everything in the universe."
This presents two equally valid ways of viewing space-time, The first is to conclude that space-time is curved since the curvature inherent in Mobius strips (plus figure-8 Klein bottles and Wick rotation) determines the shape of space-time. The second is to assume space-time is flat (uncurved ... though containing curves) since, as the journal article states, "gravity may deflect light because the latter’s photons are a key fitting into the former’s graviton-locks. This makes sense if trillions of Mobius strips make up a photon, and trillions of figure-8 Klein bottles make a graviton. Photons and gravitons fit together because Mobius strips and figure-8 Klein bottles fit together – as noted above, the second topological shape is called a Mobius Doublet since it’s a joining of two strips."
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Following article shows Einstein’s theory rewritten in flat space time.
Periodic relativity: the theory of gravity in flat space time
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from OPLS all-atom force field we can make simply using x2top command.
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Thank you ! sir Kalindu Fernando
I want to make configuration protein at oil-water interface so I created gromacs file which is I attested below but how to create topology I don't have idea.
so please can you help me do this configuration.
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Hello everyone.
Please help me to understand this agarose gel. I did a plasmid (Pgem vector with an insert with an expected size of about 3kb, from E.coli) extraction with a simple protocol Birnboim e Doly (1979). The first two bands are the different topologies of the plasmid. What I need to know is the last band (very intense) - It's very small and lower than 100bp (maker is 100bp plus). What could it be? Thanks
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Continuing on my previous answer (the ResearchGate app has some issues) - You got genomic DNA because you did the cell lysis for much too long or you vortexed the cells in the lysis buffer. The kits seperate genomic DNA from plasmid DNA by size - long DNA percipitate with cell debree
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Standard tuning for guitar E A D G B E comes around frequently but the old lute tuning E A D G C F is rarely if ever used.
Looking at the gradients, standard tuning is 0 5 5 5 4 5 and the lute tuning is 0 5 5 5 5 5, so the strings in standard span two octaves 0 5 10 15 19 24, while the lute tuning 0 5 10 15 20 25 has one more note than standard.
Same number of points, different number of notes. That makes two different topologies, so we have a collection of guitar topologies that make a theory of guitar.
When guitar strings have one note in common, they have every note in common. Then the guitars have the same set of pitch values (since they can form a union in which every note sounds in tune) but two guitars may have a different number of notes. The notes may be located at different points on guitar.
The number of notes and the number of frets on the guitar is not critical to structure because the structure is basically the same the same with a few more or less but changing the tuning by just one note is critical because it completely changes utility of the structure.
So 0 5 5 5 4 5 is a very, very good number but 0 5 5 5 5 5 is bad number.
It is clear the lute tuning is not as rich as standard because the regularity of 0 5 5 5 5 5 means that the richness of harmonic structures is reduced. For instance, if a major chord moves across the guitar so the tonic falls on successively higher string sets, the structure of the chord in lute tuning does not change. Also, many chords are difficult to play in lute tuning, so a seventh chord is quite difficult to finger. In standard, moving an E chord to the next set of strings makes an A chord, then a D chord; Moving a G chord to higher strings gives a C chord, then F. So standard tuning has 6 different shapes for a major chord, where lute tuning has only one or two.
This shows the principle of least action acts on the guitar topology as a calculus. Action in stardard is far less constrained than lute tuning.
We have here only pitch values, strings, and frets so why isn't that triple a mathematic model?
Perhaps it is this: Mathematicians want to see mathematical proof. But we can hear when pitch is equal, when one pitch is greater or less than another, and when a pitch is multiplied by two.
We know when guitar are in tuning, but we must deduce when they have the same tuning. It would be relatively easy to distinguish guitar in standard and lute tuning, even if they play the same notes. The image of guitar music has the kernal of the tuning.
The topology of music is remarkable because only ordinary math is required to understand the added structure that makes harmony or guitar, but even a brief investigation leads to the realization that the mathematics of music is special and only applies to musical instruments.
I really can't understand why mathematicians and physics are not interested in music as a formal object of study. Doesn't it bug you when you can't understand an everyday object like guitar?
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I'm not sure exactly what your goal is here. My overview: if you know the tuning of the guitar (the absolute reference pitch of the lowest string and the intervals of the strings in standard tuning) you can determine the resulting pitches of any tablature depiction. I think most guitarists develop a schema or map of the neck that they learn to navigate to find specific notes and note combinations. Expert guitarists have a deeper understanding of the pitch space of the guitar neck than could be represented by tablature notation. Tablature is used primarily by guitarists who haven't developed that deeper understanding: it's a mechanical method to find particular sounds, it is not music notation in the strict sense of the word, it merely tells the player where to put their fingers, not the sounds that will be produced. Because there a single pitch can be found in several places on the neck, the topology of the guitar kind of "folds in on itself" in places, as opposed to a typical piano keyboard which is a simple low-to-high topology.
So, if you could clarify what your end goal is here, more useful comments could be made.
Referring to your final question: I think physicists and mathematicians ARE interested in music as an object, and I think musical instruments, like guitars, are objects of study. Read a few things: Hall, Donald E. Musical Acoustics, 3rd edition. Brooks/Cole, 2001; Partch, Harry, The Genesis of a Music, Da Capo Press; 2nd edition (August 22, 1979); and others for in depth explication of tuning and instrumentation. Partch is interesting because he created an intonation system and invented a whole set of instruments to play his music. You can find my masters thesis on Partch, 40 years old, here: https://www.academia.edu/84012831/Harry_Partch_And_on_the_Seventh_Day_Petals_Fell_on_Petaluma.
Anyway, perhaps I'm missing the point here. Please let me know how much I've missed the mark.
Matthew Nicholl
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Dear Colleagues,
I've just prepared small portion of code in APDL that builds a simple specimen. It uses geometrical symmetry and VGLUE command. And here is my question: i am not sure if vglue is the same thing as Share topology. Can anyone help and explain whats the difference? The other question is related with VSYM command. I've noticed that when i tried to combine my solids into one solid with vadd,1,2,3,4 command, the edges in geometrical model still exist. Is there any (more efficient) substitution for vadd command to combine my solids into one and removing imprinted edges?
Here is my code:
FINISH
/CLEAR,START
/PREP7
k,1,0,0,0
k,2,15,0,0
k,3,15-((100*3**(0.5))/32),100/32,0
k,4,0,100/32,0
lstr,1,2
lstr,2,3
lstr,3,4
lstr,4,1
al,all
pcirc,5,,0,90
aadd,1,2
/pnum,area,1
aplot
csys,wp
wpcsys,1,0
wpoffs,0,2*100-0.5*100,0
pcirc,100/6,,-90,90
wpcsys,1,0
rectng,0,100/2,0,2*100
/pnum,area,1
aplot
voffst,1,-7
voffst,2,-7
voffst,3,-7
/facet,wire
/pnum,area,0
/pnum,volu,1
vplot
vsbv,2,1
vsbv,4,3
/facet,norml
vplot
allsel
vsym,y,1
!/facet,wire
/replo
vsel,s,volu,,1,2,1
cm,objetosci,volu
allsel
vsym,x,objetosci
cmdele,objetosci
vglue,all ! ShareTopology??
ET,1,SOLID187
esize,005
vmesh,all
vplot
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VGLUE connects volumes more efficiently than shared topology. You don't have to worry about the edges still existing as they may provide you with better mesh control. In your case, you could have created just one quarter including mesh and reflect it all using VSYMM. Then just merge nodes and keypoints using NUMM.
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Protein-Ligand Complex was generated after performing site-specific docking in AutoDock 4.2.
I am following the MD-Tutorials by Justin Lemkul.
Often bulky antibiotics are administered for therapeutic purposes. For building topologies for protein and ligands, both are separated using the 'grep' command.
When the ligands are visualised in Avogadro, sometimes the ligands seem broken or distorted thereby unfit for topology building.
I'm Using GROMACS 2020.1, CHARMM force field (Feb 2021), CGenFF server for building ligand topology.
Kindly provide some suggestions to resolve the issue.
Thanking you in advance
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Hi Researchers,
After 1 year of intense research on molecular dynamics simulation, myself and my team was able to troubleshoot the issue. I'll summarize the steps in a few points...
1. Use 3D ligand coordinates for performing molecular docking analysis
2. If Avogadro is throwing some errors, UCSF Chimera is another powerful standalone tool that can also be used for satisfying its valences and saving the optimized structure in desired MOL2 format
3. If the problem still persists, I personally suggest performing quantum chemical optimization simulation for the ligand before subjecting to molecular docking analysis
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Hi everyone, I want to start the discussion about what is the basic concepts, uses, benefits, finding and open problems in the field of Topological Indices. I hope you can contribute to the discussion.
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The potential of a topological index is to predict the physical property. The mathematical calculation helps to find a lot but which one index has power to predict the properties and which technique and index is most useful. I hope it needs thorough investigation to revise and reformulate new descriptors.
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I am working on topology optimization for photonic devices. I need to apply a custom spatial filter on the designed geometry to make it fabricable with the CMOS process. I know there exist spatial filters to remove the pixel-by-pixel and small features from the geometry. However, I have not seen any custom analytical or numerical filters in the literature. Can anyone suggest a reference to help me through this?
Thanks,
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Many thanks for your reply.
The list of papers you've provided perfectly developed the concept, particularly the tutorial paper that goes through the optimization problem step by step.
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By the triplet (X, \tau, I), we mean an ideal topological space, where \tau is a topology on X, and I is an ideal on X i.e., I is a non-empty family of some subsets of X satisfying the conditions (i) \empty \in I, (ii) M \subseteq N and N \in I implies M \in I, and (iii) M \in I, N \in I implies M \cup N \in I.
Given M \subseteq X, M* is calculated as follows:
M* = \{x \in X : U_x \cap M \notin I for every open set U_x containing x\}, called local function of M.
M \subseteq X is called *-perfect if and only if M* = M.
These are prerequisite results that will help to give answer of the question:
Suppose A \subseteq (X, \tau, I) be such that A is non-empty and A = U \cap V, where U is open and V is *-perfect. Is it true that A \subseteq A* ?
For more results and deep concept related to M*, please see the reference:
D. Jankovic and T. R. Hamlett, New topologies from old via ideals, Amer. Math. Monthly, 97 (1990), 295-310.
Thanks in advance.
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Given example primitive polynomial over finite fields especially F7^2
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Dear Colleagues,
Do you know some more or less formalized method(s) to compare topology etc. of two different taxa and some other characters of trees (not tanglegram = congruence of terminal clades). The same for haplotype networks. Question - we have 10 different networks for 10 taxa. Which two of them are most similar I e. in topology... ?
With best wishes
Alexey
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In any case there should be few common taxa. Any comparative method will address this overlapping part. I have used 2 methods: one is quartet-based. There are only 3 different topologies of a 4-leaves tree, thus one may count the ratio of similar quartets. Average ration or occasionally coinciding quartets is 1/3. If you have more, the trees are similar in the overlapping part. The other (seemingly more common) is based on phyletic distances between OTUs and is implemented in Python library ete3 (http://etetoolkit.org). Caution there: there is some format incompatibility in tree-drawing part on a linux/python-3.10 box. Hope they will fix it!
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I tried to create the topology with PRODRG but it shows that it contains a unknown metal atom Cu. The forcefield i am using is gromos53a6.
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Hello Collegues.
I am working on differential systems, i would like to know what does mean two phase portraits topologically equivalent for the same differential system?
Thank you so much.
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Thank you Sir.
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If you have for example, 5 different samples, that were sequenced, using 3 different regions, but have realised the one gene region is not powerful enough to resolve it to species level, so you add two more genes to better the topology of the phylogenetic tree
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Gosiame Boitumelo Malepe A phylogenetic tree is constructed in four separate steps: (Step 1) find and get a collection of homologous DNA or protein sequences, (Step 2) align those sequences, (Step 3) estimate a tree from the aligned sequences, and (Step 4) show that tree in such a way that the important information is clearly conveyed to others.
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I am aware of the facts that every totally bounded metric space is separable and a metric space is compact iff it is totally bounded and complete but I wanted to know, is every totally bounded metric space is locally compact or not. If not, then give an example of a metric space that is totally bounded but not locally compact.
Follow this question on the given link
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Metric space A is said to be a totally bounded if every Cauchy sequence in A has convergent sub sequence
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I am currently working on membrane protein topology research with fluorescent protein. I found so many type I membrane protein signal peptide (SP), like PDGFR or GPI domain, but very few type ii SP. I wonder if anybody could recommend some good type II membrane protein signal peptides. Thank you so much.
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Dear Rob Keller,
Thank you for your explanation. I found several signal peptides from TNFR and Rabbit neutral endopeptidase-24.11 etc works a little bit. I would try your suggestion later.
Thank you, Rob Keller .
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Fatal error: Topology include "jz4.itp" not found during P-L MD in GROMACS. But as per procedure i have added the itp file in topol.top file.Please help me resolve the same.(attached)
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Sorry , this is out of my field
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I am trying to generate OPLSA topology for LiTFSA using LigPargen tool. But it is showing an error. Are there any other tools for generating OPLSA topology parameters in Gromacs?
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I am also facing the same problem. have you got any method how to solve this problem of topology generation for non protein molecules or polymers for OPLASAA in GROMACS?
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I'm running 100 ns long MD simulations of a small peptide in isolation or bound to a partnering protein. My goal is to produce a plot of the residues in double helical form from start to end along with a video of the structure using Chimera.
The steps I take after a MD run are...
Step 1:
Center the trajectory file:
gmx trjconv -s md_0_1.tpr -f md_0_1.xtc -o md_0_1_noPBC.xtc -pbc mol -center
--- Type 1 for protein and then on the next prompt 0 for system.
Step 2:
Calculate the back bone rmsd of the entire complex:
gmx rms -s em.tpr -f md_0_1_noPBC.xtc -o rmsd_xtal.xvg -tu ns
--- Type 4 then 4 for backbone RMSD calculations
Step 3:
I then make an index file of the two chains:
gmx make_ndx -f md_0_1.gro -o index.ndx
--- Type "splitch 1" hit enter, type the number of what chain I want to reference (typically "2"), then type "q" to exit
Step 4:
From there I want to produce a trajectory file (.xtc) from the index and an updated topology (.tpr) file from my MD run using the index file:
Step 5:
Trajectory of just chain 2:
gmx trjconv -f md_0_1.xtc -s md_0_1.tpr -n index.ndx -o chain2_traj.xtc
--- Type the chain I want to reference (typically "19")
Step 6:
Topology of just chain 2:
gmx convert-tpr -s md_0_1.tpr -n index.ndx -o md_chain2.tpr
--- Type the chain I want to reference (typically "19")
Step 7:
I then center the updated files:
gmx trjconv -s md_chain2.tpr -f chain2_traj.xtc -o chain2_traj_noPBC.xtc -pbc mol -center
--- Type "1" then "0"
Step 8:
I then perform my analysis using dssp and rms
gmx do_dssp -f chain2_traj_noPBC.xtc -s md_chain2.tpr -sc scount_chain2.xvg -o ss_chain2.xpm -dt 10 -sss H
--- Type "5" for mainchain
Step 9:
gmx rms -s md_chain2.tpr -f chain2_traj_noPBC.xtc -o rmsd_xtal_chain2.xvg -tu ns
--- Type "4" then "4" for backbone rmsd
*** The issue I run across is when I open the tpr and xtc files in Chimera with the MD viewer, the peptide is completely wrong. What I've deduced is that the topology (tpr) file for some reason gives each atom in the first few residues their own residue id's. Thus residue 1 actually makes up residues 1-9 (or something similar). However, when I produce a pdb from the trajectory file (.xtc) with:
'''
gmx trjconv -s md_chain2.tpr -f chain2_traj.xtc -dt 100 -o trj.pdb
'''
The peptide is correct. So I believe the issue is that the topology file is being produced improperly due to a bug or something wrong with my steps above. I've also tried using the em.tpr file for input on step 6, but I run across the same issue. This is happening with several different peptides. One peptide that is 65 amino acids long and one that is 18 amino acids long. On the 65mer, it appears to only happen on the first 4-5 residues. ***
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As asphalt has various components, how do we create a topology for asphalt.?
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I am doing research on topology optimization, filling a unit lattice with different materials, and I want to use the homogenization theory to calculate the static effective elasticity tensor of the unit cell, as shown in the file .
How to set comsol to calculate E33 in 2D model?
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Usually, systems, where conduction electron acquires a berry phase due to noncoplanar spin structure, are topological hall effects. Is the geometric hall effect another name for the same effect?
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"In crystalline solids, where the wave vector k becomes a good quantum number, the wave function can be viewed as a mapping from the k-space to a manifold in the Hilbert space (or in its projection), and hence the topology becomes relevant to electronic states in solids" - This is a statement in the introduction of Yoichi Ando's comprehensive review on topological insulators. Ref: Ando Y., Topological insulator materials, J. Phys. Soc. Japan, (2013), 82, 102001.
I find it difficult to understand why k being a good quantum number allows for the wavefunction to be viewed as a mapping from k-space to a manifold in Hilbert space. I would appreciate insights on the statement given in quotes. Other approaches to explaining why Hilbert space topology becomes relevant to electronic states in TI are also welcome. Thanks in advance.
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Well, they lead to the localization of light which are transversal waves and have a sort of elliptical polarization, among many other interesting phenomena, Prof. Stam Nicolis
You can check for example:
Best Regards.
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1. In a TI surface state/edge state, each k state exists in pairs. The Dirac cone in a 3D-TI has a -k state for every +k state.
2. Due to spin-momentum locking caused by high Spin Orbit Coupling (SOC), the -k state will possess opposite spin to that of +k.
Am I correct in understanding that the combination of these two conditions is what makes the system be termed as a time reversal symmetry protected system? That is, k needs a -k (Kramer degeneracy), and the -k state is opposite in spin also. Hence a TR operation completely reverses the state.
If yes, my question is the following:
What physical properties (band structure, crystal structure) of a system causes a material to possess the Kramer degeneracy? That is, physically what causes a material's band structure to possess k states in pairs?
But, the kramer degeneracy theorem is defined as: 'every eigen state in a TIME REVERSAL SYMMETRIC system with half integer spin will have at least one other degenerate eigen state'. This definition makes it seem like TRS is one of the requirements for the kramer degeneracy.
I am confused about which is the cause and which is the effect here? Does TRS cause the Kramer degeneracy? Or is the presence of the Kramer degeneracy along with spin-momentum locking causing the system to be called time reversal symmetry protected?
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A good review to complement the answer by Prof. Stam Nicolis on time reversal symmetry is the classical book by Prof. A. Messiah, the chapter on symmetries and invariance, in the old separate version it was chapter XV, Dr. Abhirami Saminathan
Best Regards.