Angel J Pérez-Jiménez

Angel J Pérez-Jiménez
University of Alicante | UA · Departamento de Química Física

Professor

About

126
Publications
8,443
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
3,162
Citations
Introduction
Angel J Pérez-Jiménez currently works at the Departamento de Química Física, University of Alicante. Angel does research in Physical Chemistry, Theoretical Chemistry and Nanotechnology.
Additional affiliations
January 1994 - present
University of Alicante
Position
  • Professor

Publications

Publications (126)
Article
Full-text available
We theoretically study here the homolytic dissociation reactions of sterically crowded alkanes of increasing size, carrying three different (bulky) substituents such as tert‐butyl, adamantyl, and [1.1.1]propellanyl, employing a family of parameter‐free functionals ranging from semi‐local, to hybrid and double‐hybrid models. The study is complemente...
Article
The theoretically disclosed, and experimentally confirmed, energy inversion of the lowest singlet (S1) and triplet (T1) excited states of organic molecules (i.e., Hund’s rule violation) is investigated herein with the aid of modern and nonempirically derived double-hybrid (DH) density functionals, in the search of the best trade-off between accurac...
Article
In Chemistry, complexity is not necessarily associated to large systems, as illustrated by the textbook example of axial-equatorial equilibrium in mono-substituted cyclohexanes. The difficulty in modelling such a simple isomerization...
Article
The effective calculation of static nonlinear optical properties requires a considerably high accuracy at a reasonable computational cost, to tackle challenging organic and inorganic systems acting as precursors and/or active layers of materials in (nano‐)devices. That trade‐off implies to obtain very accurate electronic energies in the presence of...
Article
We develop and validate the SOS1-RSX-QIDH density functional, a one-parameter spin-opposite-scaled variant of the range-separated-exchange quadratic-integrand double-hybrid (RSX-QIDH) model. By entering into the family of spin-biased double hybrids, this new density functional benefits from an improved computational scaling that rivals with the one...
Article
We update the Quadratic Integrand Double-Hybrid (QIDH) model [J. Chem. Phys. 141, 031101 (2014)] by incorporating the nonempirical restored-regularized Strongly Constrained and Appropriately Normed (r2SCAN) meta-generalized gradient approximation exchange-correlation functional, thus devising a robust density functional approximation free of any em...
Article
The accurate computation of static nonlinear optical properties (SNLOPs) in large polymers requires accounting for electronic correlation effects with a reasonable computational cost. The Random Phase Approximation (RPA) used in the adiabatic connection fluctuation theorem is known to be a reliable and cost-effective method to render electronic cor...
Article
Full-text available
In this work, we focus on the understanding of the driving force behind the S1-T1 excited-state energy inversion (which would thus violate Hund's rule, making the S1 state lower in energy than the T1 state) of two non-benzenoid non-alternant hydrocarbons, composed of odd-membered rings. The molecules considered here have identical chemical composit...
Preprint
Full-text available
The accurate computation of non-linear optical properties (NLOPs) in large polymers requires accounting for electronic correlation effects with a reasonable computational cost. The Random Phase Approximation (RPA) used in the adiabatic connection fluctuation theorem is known to be a reliable and cost-effective method to render electronic correlatio...
Article
Full-text available
We theoretically study and characterize a set of rhombus-shaped nanographenes of increasing size, or n-rhombenes, where n = 2-6, displaying zigzag edges leading to an enhancement of the (poly)radicaloid nature and the appearance of intrinsic magnetism as a function of n. Due to that system-dependent radicaloid nature, we employ spin-flip methods ab...
Article
A family of non-empirical double-hybrid (DH) density functionals, such as Perdew–Burke–Ernzerhof (PBE)0-DH, PBE-QIDH, and their range-separated exchange (RSX) versions RSX-0DH and RSX-QIDH, all using Perdew-Burke-Ernzerhof(PBE) exchange and correlationfunctionals, is applied here to calculate the excitation energies for increasingly longer linear a...
Article
Full-text available
The development of universal and accurate approximations for electronic structure calculations lies at the central core of (past and modern) research in theoretical and computational chemistry. For that purpose, any reliable method needs to treat in a balanced way exchange and correlation effects arising from the intrincate structure of matter at th...
Article
In this communication, we assess a panel of 18 double-hybrid (DH) density functionals for the modeling of the thermochemistry and kinetics properties of an extended dataset of 449 organic chemistry reactions belonging to the BH9 database. We show that most of DHs provide a statistically robust performance to model barrier height and reaction energi...
Article
We calculate the relative energy between the cumulene and polyyne structures of a set of C4k+2 (k = 4-7) rings (C18, C22, C26, and C30 prompted by the recent synthesis of the cyclo[18]carbon (or simply C18) compounds. Reference results were obtained by a costly Quantum Monte-Carlo (QMC) approach, providing thus very accurate values allowing to syst...
Article
The energy difference (ΔEST) between the lowest singlet (S1) and triplet (T1) excited state of a set of azaphenalene compounds, which is theoretically and experimentally known to violate Hund's rule giving rise to the inversion of the order of those states, is calculated here with a family of double-hybrid density functionals. That excited-state in...
Article
The energy difference between singlet and triplet excitons, or ΔEST, is a key parameter for novel light-emission mechanisms (i.e., TADF or thermally activated delayed fluorescence) or other photoactivated processes. We have studied a set of conjugated molecules (peri-acenoacenes and their heteroatom-doped analogues) to observe the evolution of thei...
Article
The cover image is based on the Full Paper Assessing challenging intra‐ and inter‐molecular charge‐transfer excitations energies with double‐hybrid density functionals by Eric Bremond et al., https://doi.org/10.1002/jcc.26517
Article
We investigate the performance of a set of recently introduced range‐separated double‐hybrid functionals, namely ωB2‐PLYP, ωB2GP‐PLYP, RSX‐0DH, and RSX‐QIDH models for hard‐to‐calculate excitation energies. We compare with the parent (B2‐PLYP, B2GP‐PLYP, PBE0‐DH, and PBE‐QIDH) and other (DSD‐PBEP86) double‐hybrid models as well as with some of the...
Article
Full-text available
The synthesis of new carbon nanoforms with remarkable and fine‐tuned bulk properties still represents a formidable challenge, with cyclic organic nanorings emerging in recent years for the template‐driven design of this kind of systems. The design and engineering of these materials can be first controlled at the molecular scale, to further induce t...
Article
We recently derived a new and simple route to the determination of the range-separation parameter in range-separated exchange hybrid and double-hybrid density functionals by imposing an additional constraint to the exchange-correlation energy to recover the total energy of the hydrogen atom [Brémond et al., J. Chem. Phys. 15, 201102 (2019)]. Here,...
Article
We theoretically investigate here by means of DFT methods how the selective substitution in cyclic organic nanorings composed of pyrene units may promote semiconducting properties, analyzing the energy needed for a hole- or electron-transfer accommodation as a function of the substitution pattern and the system size (i.e. number of pyrene units). W...
Article
Recent advances in the synthesis of stable organic (open-shell) polyrad-icaloids have opened their application as active compounds for emerg-ing technologies. These systems typically exhibit small energy differ-ences between states with different spin multiplicities, which are in-trinsically difficult to calculate by theoretical methods. We thus apply...
Article
We investigate here the lowest‐energy (spin‐conserving) excitation energies for the set of He‐Ne atoms, with the family of nonempirical PBE, PBE0, PBE0‐1/3, PBE0‐DH, PBE‐CIDH, PBE‐QIDH, and PBE0‐2 functionals, after employing a wide variety of basis sets systematically approaching the basis set limit: def2‐nVP(D), cc‐pVnZ, aug‐cc‐pVnZ, and d‐aug‐cc...
Article
The recent synthesis of a C18 monocyclic ring constitutes a major breakthrough as a new all-carbon disclosed form. However, modern density functional theory approaches do not lead to the correct experimental polyynic structure and favor the cumulenic one instead. We demonstrate here that this serious drawback can be solved by recently developed ran...
Article
The scalable production of homogeneous, uniform carbon nanomaterials represents a key synthetic challenge for contemporary organic synthesis as nearly all current fabrication methods provide heterogeneous mixtures of various carbonized products. For carbon nanotubes (CNTs) in particular, the inability to access structures with specific diameters or...
Article
In this communication, we present a new and simple route to derive range-separated exchange (RSX) hybrid and double hybrid density functionals in a nonempirical fashion. In line with our previous developments [Brémond et al., J. Chem. Theory Comput. 14, 4052 (2018)], we show that by imposing an additional physical constraint to the exchange-correla...
Preprint
The scalable production of homogenous, uniform carbon nanomaterials represents a key synthetic challenge for contemporary organic synthesis as nearly all current fabrication methods provide heterogenous mixtures of various carbonized products. For carbon nanotubes (CNTs) in particular, the inability to access structures with specific diameters or c...
Article
Cyclic oligophenylenes possess remarkable electronic properties and are considered as viable templates for the hierarchical synthesis of well‐defined single‐walled carbon nanotubes. In article number 1801948, Andrés Pérez‐Guardiola, Ángel José Pérez‐Jiménez, Luca Muccioli, and Juan Carlos Sancho‐García demonstrate how these molecules can self‐assem...
Article
Full-text available
The nanoscale organization of cycloparaphenylene molecules when physisorbed on a graphite surface is theoretically investigated by means of atomistic molecular dynamics simulations employing a tailored and benchmarked force field. The landing of a single molecule is first considered, to progressively deposit more molecules to finally reach the full...
Article
We systematically investigate the relationships between structural and electronic effects of finite size zigzag or armchair carbon nanotubes of various diameters and lengths, starting from a molecular template of varying shape and diameter, i.e. cyclic oligoacene or oligophenacene molecules, and disclosing how adding layers and/or end-caps (i.e. he...
Article
The role of donor-acceptor (D-A) moieties on magnitudes such as reorganization energies and electronic couplings in CycloParaPhenylenes (CPP) carbon based nanohoops (i.e. conjugated organic molecules with cyclic topology) is highlighted via model computations and analysis of the available crystalline structure of N,N-dimethylaza[8]CPP. For the sake...
Preprint
pre>We theoretically investigate, by means of atomistic molecular dynamics simulations employing a tailored and benchmarked force field, the nanoscale organization of cycloparaphenylene molecules when physisorbed on a graphite surface. The landing of a single molecule is first considered, to progressively deposit more molecules to finally reach the...
Preprint
We systematically investigate the relationships between structural and electronic effects of finite size zigzag or armchair carbon nanotubes of various diameters and lengths, starting from a molecular template of varying shape and diameter, i.e. cyclic oligoacene or oligophenacene molecules, and disclosing how adding layers and/or end-caps (i.e. he...
Article
We apply a recently developed parameter-free double-hybrid density functional belonging to the quadratic-integrand double-hybrid model to calculate association energies (ΔE) and three-body effects (Δ³E) arising from intermolecular interactions in weakly bound supramolecular complexes (i.e., the dataset 3B-69). The model behaves very accurately for...
Article
On the basis of our previous developments in the field of nonempirical double hybrids, we present here a new exchange-correlation functional based on a range-separated model for the exchange part and integrating a nonlocal perturbative correction to the electron correlation contribution. Named RSX-QIDH, the functional is free from any kind of empir...
Article
We discuss the nature of electron-correlation effects in carbon nanorings and nanobelts by the analysis tool known as fractional occupation number weighted electron density (ρFOD) and the RAS-SF method, revealing for the first time significant differences in static correlation effects depending on how the rings (i.e. chemical units) are fused and/o...
Article
We perform a theoretical study on a set of carbon nanorings (CycloParaPhenylenes or CPP) envisioned as molecular templates for the selective synthesis of carbon nanotubes. The shape of these precursors, originating from bending n phenylene units in para position until forming the corresponding nanoring [n]CPP, may drive the growth of armchair singl...
Article
We theoretically characterize a series of substituted cycloparaphenylene nanohoops to study the effect of incorporating an electron-withdrawing group into their cyclic structure. We systematically vary the nature, position, and number of nitrogen-containing acceptor groups in both neutral (pyridine) and charged forms (pyridinium and methylpyridiniu...
Article
The EX6-0, EX7-0 and EX7-1 representative benchmark sets are developed for the fast evaluation of the performance of a density functional, or more generally of a computational protocol, in modeling low-lying valence singlet-singlet excitation energies of organic dyes within the range of 1.5 to 4.5 eV. All sets share the advantage of being small (a...
Article
We study the orbital-dependence of three (parameter-free) double-hybrid density functionals, namely the PBE0-DH, the PBE-QIDH models, and the SOS1-PBE-QIDH spin-opposite-scaled variant of the latter. To do it, we feed all their energy terms with different sets of orbitals obtained previously from self-consistent density functional theory calculatio...
Article
We theoretically discuss here the relationship between the structure of a set of halogenated and cyanated molecules containing the rubicene moiety, and a set of relevant electronic properties related to the opto-electronic and semiconductor character of these systems, namely: frontier molecular orbital shape and energy levels, electron affinity, io...
Chapter
Carbon nanohoops are sizeable structures formed upon bending a finite number of para-phenylene or benzene rings until a closed and bent structure is reached. These strained molecules are, respectively, named as [n]cycloparaphenylenes (or [n]CPP) and [n]cyclacenes (or [n]CC), where n represents the number of repeat units. They have recently attracte...
Article
We investigate here, by applying dispersion-corrected theoretical methods, the energy stability of dimers formed by [n]cycloparaphenylene molecules (n = 5, 6, 7, 8, 10, and 12 being the number of benzene rings strained to form the nanoring) when they self-assemble in crystalline samples. Their cyclic topology confers to these samples a rich variety...
Article
We theoretically discuss here the relationships between the structure of recently synthesized nanorings, dubbed as cyclo-2,7-pyrenylenes (CPY) and formed upon bending and bonding a finite number of pyrene units until self-cyclation, and a set of chemically relevant properties such as the induced structural and energetical strain, the electronic and...
Chapter
By quantum-chemical calculations, here, we ascertain the intrinsic electronic and conducting properties of molecular material prototypes for graphene-based nanostructures, and how these properties evolve as a function of their size with an increased dimensionality (from quasi-one dimensional in the case of isolated nanoribbons to three-dimensional...
Article
We have studied the role played by cyclic topology on charge-transfer properties of recently synthesized π -conjugated molecules, namely the set of [n]cycloparaphenylene compounds, with n the number of phenylene rings forming the curved nanoring. We estimate the charge-transfer rates for holes and electrons migration within the array of molecules i...
Article
We propose two analytical expressions aiming to rationalize the spin-component-scaled (SCS) and spin-opposite-scaled (SOS) schemes for double-hybrid exchange-correlation density-functionals. Their performances are extensively tested within the framework of the nonempirical quadratic integrand double-hybrid (QIDH) model on energetic properties inclu...
Article
We assess here the reliability of orbital optimization for modern double-hybrid density functionals such as the parameter-free PBE-QIDH model. We select for that purpose a set of closed- and open-shell strongly and weakly bound systems, including some standard and widely used datasets, to show that orbital optimization improves the results with res...
Article
Full-text available
We theoretically study the excited-state properties of cycloparaphenylenes ([n]CPPs) for a deeper understanding of their photochemical properties with increasing size n, being $$n = 6-12$$n=6-12 the number of repeat units forming the nanoring. We apply hybrid (e.g., PBE0 and PBE0-1/3), double-hybrid (e.g., PBE0-DH and PBE-QIDH) and range-separated...
Article
In this letter we report the error analysis of 59 exchange-correlation functionals in evaluating the structural parameters of small- and medium-sized organic molecules. From this analysis, recently developed double-hybrids, such as xDH-PBE0, emerge as the most reliable methods, while global-hybrids confirm their robustness in reproducing molecular...
Article
The functionality of weakly bound organic materials, either in Nanoelectronics or in Materials Science, is known to be strongly affected by their morphology. Theoretical predictions of the underlying structure-property relationships are frequently based on calculations performed on isolated dimers, but the optimized structure of the latter may sign...
Article
It is suggested here that the ultimate accuracy of DFT methods arises from the type of hybridization scheme followed. This idea can be cast into a mathematical formulation utilizing an integrand connecting the noninteracting and the interacting particle system. We consider two previously developed models for it, dubbed as HYB0 and QIDH, and assess...
Article
We have systematically analyzed the performance of some representative double-hybrid density functionals (including PBE0-DH, PBE-QIDH, PBE0-2, XYG3, XYGJ-OS, and xDH-PBE0) for a recently introduced database of diene isomerization energies. Double-hybrid models outperform their corresponding hybrid forms (for example, PBE0-DH, PBE0-2, and PBE-QIDH a...
Article
Cycloparaphenylenes (CPPs) are nanosized structures with unique isolated and bulk properties, and are synthetic targets for the template-driven bottom-up synthesis of carbon nanotubes. Thus, a systematic understanding of the supramolecular order at the nanoscale is of utmost relevance for molecular engineering. In this study, it is found that intra...
Article
We investigate the cohesive energy of crystalline coronene by the dispersion-corrected methods DFT-D2, DFT-D3, and DFT-NL. For that purpose, we first employ bulk periodic boundary conditions and carefully analyze next all the interacting pairs of molecules within the crystalline structure. Our calculations reveal the nature and importance of the bi...
Article
Full-text available
We have carefully investigated the structural and electronic properties of coronene and some of its fluorinated and chlorinated derivatives, including full periphery substitution, as well as the preferred orientation of the non-covalent dimer structures subsequently formed. We have paid particular attention to a set of methodological details, to fi...
Article
Full-text available
A new approach stemming from the adiabatic-connection (AC) formalism is proposed to derive parameter-free double-hybrid (DH) exchange-correlation functionals. It is based on a quadratic form that models the integrand of the coupling parameter, whose components are chosen to satisfy several well-known limiting conditions. Its integration leads to DH...
Article
Computational methods are used recently as reliable tools to uncover the properties of novel conjugated organic materials and understand the physico-chemical mechanism that ultimately controls the overall organic-based device efficiency. Since modelling of charge transport across organic layers needs to address simultaneously single molecule proper...
Article
The generation of mobile charges and their transport across organic layers are commonly the most critical steps affecting the performance of organic-based electronic devices. Charge-transport properties are often described by quantum-chemical calculations which, however, face a challenge when the nanostructure of the material has to be concomitantl...
Article
Theoretical modeling is used here to ascertain the potential use of circumacenes to improve the transport parameters of pi-conjugated materials acting as: (i) the layered molecular constituent for organic electronic devices; and (ii) the molecular component of gold-molecule-gold nanobridges for molecular electronic device use. It is concluded that,...
Article
There have been tremendous efforts in the past decade on the use of computational methods for conjugated systems. Their properties and energetics are often described by density functional theory calculations which, however, are known to face a challenge when dealing with these systems since serious and systematic errors with popular density functio...
Article
First-principles calculations on gold-pentacene-gold and several gold-circumacene-gold nanojunctions indicate that their low-bias conductance is due to the onset of a HOMO-derived resonance, thus being quite sensitive to the detailed interaction between the molecule and the gold leads. It is also found that such interaction is dominated by the elec...
Article
Full-text available
The current success of Density Functional Theory applications hinges upon the availability of explicitly density-dependent functionals to self-consistently solve a set of one-electron equations, the Kohn–Sham (KS) equations, which determine the occupied orbitals and its associated electronic density. In KS theory, a local exchange potential is prop...
Article
The current success of Density Functional Theory applications hinges upon the availability of explicitly density-dependent functionals to self-consistently solve a set of one-electron equations, the Kohn–Sham (KS) equations, which determine the occupied orbitals and its associated electronic density. In KS theory, a local exchange potential is prop...
Article
The semiconducting properties of molecular material prototypes for graphene nanoribbons are rationalized by quantum-chemical calculations. The present contribution focuses on the hole transport properties of circum(oligo)acenes and compares the intrinsic efficiency of these materials for charge transport in the hopping regime with respect to the (o...
Article
The current research on molecular-based devices built with highly unsaturated molecules is largely assisted by computational techniques. These modern computational tools are intended to serve (i) to understand the relation between the mechanism of charge transport and the chemical composition of the semiconductors and (ii) to perform the molecular...
Article
At ambient temperatures, intermolecular hopping of charge carriers dominates the field effect mobility and thus the performance of organic molecular semiconductors for organic-based electronic devices. We have used a wide variety of modern and accurate computational methods to calculate the main parameters associated with charge transport, taking o...
Article
The theoretical challenge of finding a single method that quantitatively reproduces both the experimental low-lying excitation energies and the torsional barrier of a prototypical conjugated molecule, which could act as a molecular wire, has been addressed here. The results indicate that this goal can be reasonably achieved when multi-reference per...
Article
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Article
The difference between the length of the central carbon-carbon bond and that of the adjacent flanked double bonds in polymers such as polyacetylene is closely related to their electronic properties and plays a central role in their conductivity upon doping. Simple as it seems, this bond length alternation (BLA) is a difficult test for many theoreti...
Article
We study the performance of different approaches that combine multiconfigurational wavefunctions with correlation functionals for the calculation of magnetic coupling constants of several materials and molecules. The systems under study include four antiferromagnetic materials: NiO, KNiF(3), K(2)NiF(4) and La(2)CuO(4); two biradicals: alpha-4-Dehyd...
Article
Controlling the positions of the encapsulated atoms in endohedral metallofullerenes may help in designing functional devices for molecular electronics. Ab initio calculations performed here show that both the positions of the La atoms and the electronic transport through La2@C80−metal nanojunctions are largely influenced by the metallic leads, whic...
Article
Dianions derived from arenes of high reduction potential (biphenyl, naphthalene) and Li(s) can carbometallate propene, isobutene or norbornene among other alkenes, in an intermolecular fashion. This reaction runs at room temperature to afford partially dearomatized alkylated aryl anions that are susceptible to further functionalization by electroph...
Article
Full-text available
We propose a procedure that combines multiconfigurational (MC) wave functions with two-body density correlation functionals by transforming the latter into functionals of the MC natural orbitals and occupation numbers. The method is tested with the spectroscopic constants of a set of 11 diatomics, the diradical-involved automerization barrier of cy...
Article
Full-text available
We propose a size-consistent method to combine small active space multiconfigurational self-consistent-field (MCSCF) wave functions with standard correlation energy density functionals. The correlation energy is not evaluated from the standard spin densities but from a pair of alternative densities obtained from the natural orbitals and occupation...
Article
Full-text available
Recently proposed spin-dependent and spin-independent correlation energy functionals [Perez-Jimenez et al., J. Chem. Phys. 116, 10571 (2002)] based on an effective number of electrons N are extended to deal with charged systems. By introducing the concept of an effective atomic number Z analogous to N, the spin-dependent functional in combination w...
Article
Ab initio calculations using restricted Hartree-Fock, second-order Møller-Plesset perturbation theory (MP2), density-functional theory (DFT), and coupled-cluster methods have been done to obtain the torsional potential-energy profile of the aza-aromatic molecule 4,4'-bipyridine. The torsional potential is evaluated adiabatically by fixing the norma...
Article
Here, the fascinating connection between the chemical and the transport properties of recently fabricated 4,4'-bipyridine/gold nanobridges is addressed. By means of first-principles ab initio calculations, the remarkable reproducibility of the 4,4'-bipyridine conductance properties is explained as the combined result of (i) the bonding of the molec...
Chapter
In this review we discuss the fundamental issues underlying first-principles quantum transport theory in molecular- and atomic-scale systems, making emphasis on the actual numerical implementation of them. For this purpose we focus on the ab initio method named Gaussian Embedded Cluster Method, recently developed by the authors, which is based on t...
Article
Full-text available
One of the major industrial challenges is to profit from some fascinating physical features present at the nanoscale. The production of dissipationless nanoswitches (or nanocontacts) is one of such attractive applications. Nevertheless, the lack of knowledge of the real efficiency of electronic ballistic/non dissipative transport limits future inno...
Article
Full-text available
It has been reported that conductance fluctuations in noble and monovalent metals nanocontacts oscillate with conductance, showing minima near integer multiples of the conductance quantum. Most observed features were reproduced by means of a model based on the Landauer-Buttiker approach, but the enhancement of the peak at conductances smaller than...
Article
A global survey of the correlation factor energy functionals and its application to atomic and molecular properties is made. Its performances are compared with those of the density functional theory (DFT) correlation energy functionals, and some interesting conclusions from previous publications are reinforced here; namely, after removing the one-S...
Article
Full-text available
A new method to improve the excess spin density obtained from unrestricted Hartree-Fock wave functions in terms of natural orbitals is proposed. Using this modified excess spin density to evaluate the correlation energy by means of density functionals leads to large improvements in the computed magnetic coupling constants of several materials witho...
Article
Full-text available
We present a state-of-the-art first-principles analysis of electronic transport in a Pt nanocontact in the presence of H-2 which has been recently reported by Smit [Nature (London) 419, 906 (2002)]. Our results indicate that at the last stages of the breaking of the Pt nanocontact two basic forms of bridge involving H can appear. Our claim is, in c...
Article
A detailed study on the torsional potential of nitrobenzene is performed by using state-of-the-art ab initio methods, including density functional theory (DFT) ones. Special emphasis is given to basis set incompleteness in order to get complete agreement with experimental results. On the other hand, the DFT derived the energy difference between pla...
Article
We report on the first principles determination of the conductance properties of Buckminster fullerene adsorbed on a gold surface, comparing them with recent Scanning Tunneling Microscopy/Spectroscopy (STM/S) experiments [J.Chem.Phys.116, 832 (2002)]. Our procedure has the two appealing features of being able to elucidate delicate aspects of STM/S...