Lola Gonzalez-Sanchez

• University of Salamanca

The anions CN− and C3N−, both as $^1 \Sigma _g^+$ electronic states, are among the oldest of the (C,N)-bearing linear anions discovered in the dark cloud core, TMC-1, more than 15 years ago by now. They are also interesting species to be studied in cold trap conditions that can mimick those temperature ranges that are dominant in the astrophysical...

We investigate an optical cycling scheme for Doppler cooling cold trapped ¹¹B¹⁴N⁻ ions using transitions between the X 2Σ⁺ ground state and the B ²Σ⁺ excited state, and analyze here the relevant transitions for photon cycling and repumping. Our results show that slow population decay via the first excited electronic state A 2Π cannot be neglected....

The active site architecture of all heme enzymes is designed for fully controlled formation of highly reactive heme intermediates for oxidative catalysis. Finely tuned proton delivery to and from the heme, substrates and active site water molecules is essential, yet the mechanisms of proton delivery and the sources of protons are poorly understood...

We present the temperature-dependent reaction rate coefficients of CN ⁻ and C 3 N ⁻ with atomic hydrogen in the temperature range from 7 to 290 K, measured in a 16-pole radio-frequency ion trap. The rate of C 3 N ⁻ with H steadily increases toward lower temperatures, while the rate coefficients for the CN ⁻ + H system show a sudden change around 16...

An excellent agreement for simulated and measured absorption and emission spectra is found for four donor‐acceptor aromatic molecules (tetraphenylpyrazine, tetraphenylethene, distirylanthracene and hexaphenylsilole) whose derivatives serve as solid state photosensitizers. After comparing several hybrid TDDFT functionals, EOM‐CCSD, and experiments,...

The anions C$_7$N$^-$ and C$_{10}$H$^-$ are the two longest of the linear (C,N)-bearing and (C,H)-bearing chains which have so far been detected in the Interstellar Medium. In order to glean information on their collision-induced rotational state-changing processes, we analyse the general features of new ab initio potentials describing the interact...

The anions C7N− and C10H− are the two longest of the linear (C,N)-bearing and (C,H)-bearing chains which have so far been detected in the Interstellar Medium. In order to glean information on their collision-induced rotational state-changing processes, we analyse the general features of new ab initio potentials describing the interaction of both li...

Fridericia chica is an Amazonian plant used to treat stomach disorders. However, the pharmacological activity of flavonoids in the extract has yet to be investigated. Therefore, we considered that a flavonoid-rich F. chica subfraction (FRS) has gastroprotective functions. For this, before the induction of gastric ulcers with ethanol or piroxicam, t...

Water is a key ingredient for the emergence of life as we know it. Yet, its destruction and reformation in space remain unprobed in warm gas (T > 300 K). Here we detect with the James Webb Space Telescope the emission of the hydroxyl radical (OH) from d203-506, a planet-forming disk exposed to external far-ultraviolet (FUV) radiation. These observa...

The O(3P)+D2 --> OD(2Pi)+D reaction presents the peculiarity of taking place on two different potential energy surfaces (PESs) of different symmetry, $^3A'$ and $^3A''$, which are degenerate for collinear configurations...

We report new results from quantum calculations of energy-transfer processes taking place in interstellar environments and involving two newly observed molecular species: C 5 N ⁻ and C 7 N ⁻ in collision with He atoms and p–H 2 molecules. These species are part of the anionic molecular chains labeled as cyanopolyynes, which have been observed over...

Context . The global context of making numerous data produced by researchers available requires collecting and organising the data, assigning meaningful metadata, and presenting the data in a meaningful and homogeneous way. The BASECOL database, which collects inelastic rate coefficients for application to the interstellar medium and to circumstell...

We report quantum calculations involving the dynamics of rotational energy-transfer processes, by collision with He atoms in interstellar environments, of the title molecular species which share the presence of the CN backbone and are considered of importance in those environments. The latter structural feature is taken to be especially relevant fo...

Assuming a delta pulse excitation, quantum wavepackets are propagated on the excited state manifold in the energy range from 3.4-5.0 eV for coronene and 2.4-3.5 eV for circumcoronene to study the time evolution of the states as well as their lifetimes. The full-dimensional (102 and 210 degrees of freedom for coronene and circumcoronene respectively...

Molecular ions have been ubiquitous in a variety of environments in the interstellar medium, from Circumstellar Envelopes to Dark Molecular Clouds and to Diffuse Clouds. Their role in the multitude of molecular processes which have been found to occur in those environments has been the subject of many studies over the years, so that we have acquire...

The anion C5N− is one of the largest linear (C,N)-bearing chains detected in the Interstellar Medium. Here we present and discuss the general features of new ab initio potential energy surfaces describing the interaction of this linear anion with He and H2. We employ a Legendre Polynomials expansion representation for the former and an artificial n...

The deprotonation of an organic substrate is a common preactivation step for the enzymatic cofactorless addition of O2 to this substrate, as it promotes charge-transfer between the two partners, inducing intersystem crossing between the triplet and singlet states involved in the process. Nevertheless, the spin-forbidden addition of O2 to uncharged...

We present accurate ab initio calculations on several properties of a gas-phase system of interest in the interstellar medium (ISM), where the title molecular anion has been often surmised but not yet confirmed by observations. The CH-3Σ+ constitutes the smallest term in the series of longer anionic polyynes which have been observed in the ISM (e.g...

We report for the first time an accurate ab initio potential energy surface for the HeH+-H2 system in four dimensions (4D) treating both diatomic species as rigid rotors. The computed ab initio potential energy point values are fitted using an artificial neural network method and used in quantum close coupling calculations for different initial sta...

By extending an earlier study [Gianturco et al., J. Chem. Phys. 154, 054311 (2021)] on the purely rotational excitation of HeH⁺ by He atoms, we report in this paper integral cross sections and rate coefficients for rovibrational excitation and de-excitation processes in HeH⁺ due to collisions with He. The data were obtained using a new ab initio po...

Ab initio calculations are employed to generate the rigid rotor (RR) potential energy surface (PES) describing the interaction of the linear molecular cation HeHHe+, at its equilibrium geometry, with the neutral He atom. The resulting interaction is employed to investigate the efficiency of rotational state-changing collisions at the temperatures r...

In spite of being spin-forbidden, some enzymes are capable of catalyzing the incorporation of O₂ (³Σ⁻_g) to organic substrates without needing any cofactor. It has been established that the process followed by these enzymes starts with the deprotonation of the substrate forming an enolate. In a second stag...

In spite of being spin-forbidden, some enzymes are capable of catalyzing the incorporation of O2(Σg-3) to organic substrates without needing any cofactor. It has been established that the process followed by these enzymes starts with the deprotonation of the substrate forming an enolate. In a second stage, the peroxidation of the enolate formation...

The vibrational quenching cross sections and corresponding low-temperature rate constants for the ν = 1 and ν = 2 states of CN⁻(¹Σ⁺) colliding with He and Ar atoms have been computed ab initio using new three-dimensional potential energy surfaces. Little work has been carried out so far on low-energy vibrationally inelastic collisions for anions wi...

Two different ab initio potential energy surfaces are employed to investigate the efficiency of the rotational excitation channels for the polar molecular ion HeH⁺ interacting with He atoms. We further use them to investigate the quantum dynamics of both the proton-exchange reaction and the purely rotational inelastic collisions over a broad range...

The vibrational quenching cross sections and corresponding low-temperature rate constants for the v = 1 and v = 2 states of CN- colliding with He and Ar atoms have been computed ab initio using new three dimensional potential energy surfaces. Little work has so far been carried out on low-energy vibrationally inelastic collisions for anions with ne...

Two different ab initio potential energy surfaces are employed to investigate the efficiency of the rotational excitation channels for the polar molecular ion HeH$^+$ interacting with He atoms. We further use them to investigate the quantum dynamics of both the proton-exchange reaction and the purely rotational inelastic collisions over a broad ran...

Despite being a very strong oxidizing agent, most organic molecules are not oxidized in the presence of O2 at room temperature because O2 is a diradical whereas most organic molecules are closed‐shell. Oxidation then requires a change in the spin state of the system, which is forbidden according to non‐relativistic quantum theory. To overcome this...

The dicarbon molecular anion is currently of interest as a candidate for laser cooling due to its electronic structure and favorable branching ratios to the ground electronic and vibrational states. Helium has been proposed as a buffer gas to cool the molecule's internal motion. We calculate the cross sections and corresponding rates for rovibratio...

The molecular anion C2− is currently of interest as a candidate for laser cooling due to its electronic structure and favorable branching ratios to the ground electronic and vibrational states. Helium has been proposed as a buffer gas to cool the molecule's internal motion. We calculate the cross sections and corresponding rates for rovibrational i...

Scattering resonances are pure quantum effects that appear whenever the collision energy matches the energy of a quasi-bound state of the intermolecular complex. Here we show that rotational quenching of HF(j = 1, 2) with H is strongly influenced by the presence of two resonance peaks, leading to up to a two-fold increase in the thermal rate coeffi...

The potential energy surfaces for C�2(2Sþg) interacting with He, Ne and Ar are calculated usingab initioquantum chemistry methods. The PES are used to carry out coupled-channel quantum scattering cal-culations for the three systems to obtain the rotationally inelastic scattering cross sections from whichthe rotationally inelastic state-changing rat...

Using the ab initio computed Potential Energy Surface (PES) for the electronic interaction of the MgH$^+$ ($^1\Sigma$) ion with the He($^1$S) atom, we calculate the relevant state-changing rotationally inelastic collision cross sections from a quantum treatment of the multichannel scattering problem. We focus on the quantum dynamics at the translat...

We present an extensive range of quantum calculations for the state-changing rotational dynamics involving two simple molecular anions which are expected to play some role in evolutionary analysis of chemical networks in the Interstellar environments, C$_2$H$^-$($X^1\Sigma^+$) and C$_2$N$^-$ ($X^3 \Sigma^-$) but for which inelastic rates are only k...

We employ potential energy surfaces (PES) from ab initio quantum chemistry methods to describe the interaction of the CN⁻(¹Σ) molecule, one of the small anions often studied at low temperatures, with other possible gases which can be employed as buffer in cold ion traps: the He and Ar atoms and the p-H2 molecule. These PESs are used to calculate fr...

Resonances are associated with the trapping of an intermolecular complex, and are characterized by a series of quantum numbers such as the total angular momentum and the parity, representative of a specific partial wave. Here we show how at cold temperatures the rotational quenching of HF(j=1,2) with H is strongly influenced by the presence of mani...

A newly calculated ab initio potential energy surface is used to compute collision-driven state-changing cross sections and rate coefficients over a range from 5 to 100 K for CN−(1Σ), the smallest anion detected in the interstellar medium, interacting with He, an abundant species in this environment. We compare our presently computed rate coefficie...

We present a computational investigation of the photodetachment (PD) dynamics of C 2 H ⁻ in its ground, electronic ¹ Σ state, cooled in an ion trap with He as a buffer gas. Our analysis employs a range of PD rates from quantum dynamics, selective choices of the anion’s initial rotational state populations as the laser is switched on, and different...

We present an extensive range of quantum calculations for the state-changing rotational dynamics involving two simple molecular anions that are expected to play some role in the evolutionary analysis of chemical networks in the interstellar environments, C2H⁻ (X¹Σ⁺) and C2N⁻ (X³Σ⁻), but for which inelastic rates are only known for C2H⁻. The same sy...

Oxygenases are a family of enzymes that catalyse the breaking of molecular oxygen with incorporation of, at least, one oxygen atom into an organic substrate. Since molecular oxygen is a diradical and most organic molecules have no unpaired-electrons, reactions catalysed by oxygenases involve changes in the spin state of the system that are forbidde...

We discuss in detail the quantum rotationally inelastic dynamics of an important anion often discussed as a possible constituent of the interstellar medium (ISM) and in different environments of circumstellar envelopes: the ${{\rm{C}}}_{2}^{-}$ molecular ion. Its interaction forces with one of the most abundant atoms of the ISM, the neutral helium...

Using accurate ab initio calculations of the interaction forces, we employ a quantum mechanical description of the collisional state-changing processes that occur in a cold ion trap with He as a buffer gas. We generate the corresponding inelastic rates for rotational transitions involving three simple molecular anions OH⁻(¹Σ), MgH⁻(¹Σ), and C2H⁻(¹Σ...

The dynamics of the inelastic collisions between HF and H has been investigated in detail by means of Time-Independent Quantum Mechanic calculations on the LWA-78 PES [Li et al. J. Chem. Phys.,2007,127, 174302]. Reaction probabilities, differential cross sections as well as three-vector correlations have been calculated and analized. Our results sh...

We present in this paper a detailed theoretical and computational analysis of the quantum inelastic dynamics involving the lower rotational levels of the MgH⁻ (X¹Σ⁺) molecular anion in collision with He atoms which provide the buffer gas in a cold trap. The interaction potential between the molecular partner and the He (¹S) gaseous atoms is obtaine...

Using the ab initio computed potential energy surface for the electronic interaction of the MgH+(Σ1) ion with the He(S1) atom, we calculate the relevant state-changing rotationally inelastic collision cross sections from a quantum treatment of the multichannel scattering problem. We focus on the quantum dynamics at the translationally low energies...

We employ an accurate, ab initio potential energy surface (PES) which describes the electronic interaction energy between the molecular anion OH$^-$ ($^1\Sigma^+$) and the neutral rubidium atom Rb ($^2S$), to evaluate the elastic and inelastic cross sections over a range of energies representative of the conditions of low-T experiments in MOT traps...

In the present paper we analyze in detail several properties of the MgH$^-$ anion and the MgH neutral molecule using accurate ab initio quantum computational methods in order to establish with higher reliability specific molecular features like the gas-phase electron affinity (EA) , the Frank-Condon (FC) factors for excitation of the neutral and of...

Multichannel scattering calculations are presented for the low-energy collisions of the OH⁺ cation and He atoms, using an ab initio evaluation of the interaction potential, which had been obtained in earlier work, and a time-independent, multichannel treatment of the quantum dynamics carried out in this study using our in-house scattering code ASPI...

We present quantum calculations for rotational state‐changing cross sections and rates, up to 50 K of ion translational temperatures,for the title molecular ion in the presence of He as a buffer gas in the trap. The results are obtained both by using the correct spin‐rotation coupling and within a recoupling scheme that treats the molecular target...

In the present paper we analyze in detail several properties of the MgH− anion and the MgH neutral molecule using accurate ab initio quantum computational methods in order to establish with a higher reliability specific molecular features like the gas-phase electron affinity, the Franck-Condon factors for excitation of the neutral and of its anion...

We have characterized the stereodynamics of the H + LiH (v = 0, j = 0-1) reactive collisions leading to H-2 formation through the quantum mechanical analysis of the k-j and k'-j' vector correlations that describe the polarization of the reactants and products, respectively. Our results, which cover the collision energy interval between 10(-4) and 1...

We report in the present study a quantum analysis of the collisional dynamics involving a negative ion, LiH⁻ in its ²Σ⁺ ground electronic state, and He as a buffer gas in the environment of cold ion traps. The work focuses on the evaluation of the internal cooling collisional rates, treating both the anion's rotational quantum numbers and the spin-...

We report close-coupling (CC) quantum dynamics calculations for collisional excitation/de-excitation of the lowest four rotational levels of OD− and of OH− interacting with Rb atoms in a cold ion trap. The calculations are carried out over a range of energies capable of yielding the corresponding rates for state-changing events over a rather broad...

We have analyzed the influence of the rotational excitation on the H+D2 reaction through quantum mechanical (QM) and quasiclassical trajectories (QCT) calculations at a wide range of total energies. The agreement between both types of calculations is excellent. We have found that the rotational excitation largely increases the reactivity at large v...

The explicit consideration of the vector correlations is an essential step when it comes to determining the mechanism of chemical reactions. Usual vector correlations involve initial and final relative velocity vectors and rotational angular momenta. However, the correlation between the orbital, ℓ, and rotational, j, angular momenta has seldom rece...

We employ an accurate, ab initio potential energy surface (PES) which describes the electronic interaction energy between the molecular anion OH− ( ) and the neutral rubidium atom Rb ( ), to evaluate the elastic and inelastic cross sections over a range of energies representative of the conditions of low-T experiments in MOT traps, when combined wi...

The dynamics and kinetics of the LiH + H reaction have been studied by using an accurate quantum reactive time-dependent wave packet method on the ab initio ground electronic state potential energy surfaces (PES) developed earlier. Reaction probabilities for the two possible reaction channels, the LiH + H→H2 + Li depletion process and the LiH + H→H...

Time-independent quantum mechanical calculations have been performed in order to to characterize the dynamics and stereodynamics of Cl + HD reactive collisions. Calculations have been carried out at two dierent total energy values and for various initial states using the adiabatic potential energy surface by Bian and Werner [J. Chem. Phys., 2000, 1...

In this work we present a dynamically biased statistical model to describe the evolution of the title reaction from statistical to a more direct mechanism, using quasi-classical trajectories (QCT). The method is based on the one previously proposed by Park and Light [J. Chem. Phys. 126, 044305 (2007)10.1063/1.2430711]. A recent global potential ene...

In this work we present a dynamically biased statistical model to describe the evolution of the title reaction from statistical to a more direct mechanism, using quasi-classical trajectories (QCT). The method is based on the one previously proposed by Park and Light [J. Chem. Phys. 126, 044305 (2007)]. A recent global potential energy surface is us...

Based on quantum mechanical scattering (QM) calculations, we have analyzed the polarization of the product hydrogen molecule in Cl + H(2) (v = 0, j = 0) inelastic collisions. The spatial arrangements adopted by the rotational angular momentum and internuclear axis of the departing molecule have been characterized and used to prove that two distinct...

While Cl + H(2) reactive collisions have been a subject of numerous experimental and theoretical studies, inelastic collisions leading to rotational energy transfer and/or vibrational excitation have been largely ignored. In this work, extensive quantum mechanical calculations covering the 0.5-1.5 eV total energy range and various initial rovibrati...

A complete quantum study for the state-to-state Li + HF(v,j,m) → LiF(v',j',Ω') + H reactive collisions has been performed using a wave packet method, for different initial rotational states and helicity states of the reactants. The state-to-state differential cross section has been simulated, and the polarization of products extracted. It is found...

A newly computed potential energy surface, which describes the forces at play between the OH− (X 1Σ+) anionic molecule (treated as a rigid rotor at its equilibrium geometry) and the Rb(2S) atomic gas was obtained from fully ab initio methods, yielding highly correlated electronic wavefunctions for the interacting partners. It is in turn employed to...

Rotationally superelastic collisions are computed from quantum dynamical calculations for the two title systems, down to the very low collision energies of interest in cold trap experiments. The results are obtained via ab initio interaction potentials, the one for the MgH-He system being given here for the first time and discussed in details in th...

Quantum coupled-channel scattering calculations have been carried out at ultralow energies (down to 10-5 K) for rotational quenching of ionic and spin-stretched states of the lithium dimer in collision with He atoms. Marked cross section differences, to be related to changes in their interactions with He, have been observed with respect to the sing...

Using ab initio calculations for the lowest, spin-stretched, quartet potential energy surfaces for Rb and Cs neutral atoms interacting with the NH({sup 3}{sigma}{sup -}) polar target, the cold collision quantum dynamics is analyzed at ultralow energies to examine possible propensity rules existing for the relaxation of either spin or rotational tar...

An ab initio computed potential energy surface is employed to evaluate the interaction of the OH+(3Σ -) molecule with 4He(1S) atom and an analytic fitting of the raw points is directly employed in quantum scattering calculations at ultralow collision energies. The Hund's case (b) chosen to handle the spin-rotation coupling allows to extract from th...

A newly computed potential energy surface which describes the interaction between the two title partners is employed to evaluate collisional quenching of the rotational levels of the OH−(X1Σ+) anion by 4He atoms at ultralow energies. The calculations are carried out within the exact coupled channel (CC) formalism and both elastic and inelastic quen...

The collisional relaxation of rotationally ``hot'' OH molecules in He as a buffer gas has been studied as a fully quantum event using an ab initio potential energy surface and the exact dynamical coupling of the relevant angular momenta during the process. The range of energies considered corresponds to the ultralow temperatures of cold traps and t...

Global three-dimensional adiabatic potential-energy surfaces for the excited 2 and 1 triplet states of OHF are obtained to study the F()+OH()→O()+HF() reaction. Highly accurate ab initio calculations are obtained for the two excited electronic states and fitted to analytical functions with small deviations. The reaction dynamics is studied using a...

Wave packet simulations of the photodetachment spectrum of OHF− are performed on several electronic adiabatic states, two triplets and four singlets of neutral OHF. The transition moments to these six states have been approximated using the ab initio electronic wave functions of OHF− and OHF calculated at the equilibrium configuration of the parent...

The reactivity dependence on the k, j vector correlation for the title reaction is studied for j¼1, 2, 3 by a quantum wavepacket method in a large range of translational energy on a recently obtained 3 A 00 adiabatic potential energy surface. It is found that the reaction is extraordinarily enhanced when initially k and j are perpendicular, or equi...

A theoretical study of the F(2P) + OH(2Pi) --> HF(1Sigma+) + O(3P) reactive collisions is carried out on a new global potential energy surface (PES) of the ground 3A" adiabatic electronic state. The ab initio calculations are based on multireference configuration interaction calculations, using the aug-cc-pVTZ extended basis sets of Dunning et al....

In this work a simulation of the OHF(-) photodetachment spectrum is performed in a three-dimensional potential energy surface recently developed for OHF((3)A(")). The ground (2)A(') state potential of the anion is calculated in three dimensions based on accurate ab initio calculations and the reaction dynamics is studied using a wave packet method....

MRCI electronic energy calculations have been carried out for the ground triplet state of the OHF reactive system. 8069 ab initio points have been fitted with a two- and three-body polynomial expansion in modified Rydberg coordinates and a high quality global potential energy surface (PES) was thus generated. On the PES, quasiclassical trajectory c...