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Rawat AMS, Sahoo J, Mahapatra S. Combined Quantum Mechanical and Quasi-Classical State-to-State Dynamical Study on the Isotopic Effect in H/D + LiH +/LiD + → H 2/HD/D 2 + Li + Reactions. J Phys Chem A 2023; 127:10733-10746. [PMID: 38096485 DOI: 10.1021/acs.jpca.3c04131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
Coriolis-coupled quantum mechanical (QM-CC) and quasi-classical trajectory (QCT) calculations are carried out to investigate the dynamics of the H(D) + LiH+(v = 0, j = 0) → H2(HD) (v', j') + Li+ reactions on the ground electronic state potential energy surface reported by Martinazzo et al. (Martinazzo et al., J. Chem. Phys. 2003, 119, 11241). The QM-CC and QCT results at the initial state-selected and state-to-state levels are used to investigate the validity and accuracy of the QCT method for these exoergic barrierless reactions. Furthermore, the QCT method is used to understand the isotopic effects on reaction observables like total and state-to-state integral cross section, differential cross section, product energy disposal, and rate constants of H(D) + LiH+(v = 0, j = 0) → H2(HD) (v', j') + Li+ and H(D) + LiD+(v = 0, j = 0) → HD(D2) (v', j') + Li+ reactions. Attempts are also made to understand the impact of the isotopic substitution on the reaction mechanism. It is observed that QM-CC and QCT results closely follow each other at the initial state-selected and state-to-state levels. Noticeable kinematic effects of reagents on the reactivity and mechanism of the reactions are also observed.
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Affiliation(s)
| | - Jayakrushna Sahoo
- School of Chemistry, University of Hyderabad, Hyderabad 500046, India
| | - S Mahapatra
- School of Chemistry, University of Hyderabad, Hyderabad 500046, India
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Koner D, Barrios L, González-Lezana T, Panda AN. Atom-Diatom Reactive Scattering Collisions in Protonated Rare Gas Systems. Molecules 2021; 26:4206. [PMID: 34299481 PMCID: PMC8304066 DOI: 10.3390/molecules26144206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/07/2021] [Accepted: 07/08/2021] [Indexed: 11/17/2022] Open
Abstract
The study of the dynamics of atom-diatom reactions involving two rare gas (Rg) atoms and protons is of crucial importance given the astrophysical relevance of these processes. In a series of previous studies, we have been investigating a number of such Rg(1)+ Rg(2)H+→ Rg(2)+ Rg(1)H+ reactions by means of different numerical approaches. These investigations comprised the construction of accurate potential energy surfaces by means of ab initio calculations. In this work, we review the state-of-art of the study of these protonated Rg systems making special emphasis on the most relevant features regarding the dynamical mechanisms which govern these reactive collisions. The aim of this work therefore is to provide an as complete as possible description of the existing information regarding these processes.
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Affiliation(s)
- Debasish Koner
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Tirupati, Karakambadi Road, Tirupati 517507, Andhra Pradesh, India;
| | - Lizandra Barrios
- Department of Chemistry, CMS—Centre for Molecular Simulation, IQST—Institute for Quantum Science and Technology and Quantum Alberta, University of Calgary, 2500 University Drive N.W., Calgary, AB T2N 1N4, Canada;
| | | | - Aditya N. Panda
- Department of Chemistry, Indian Institute of Technology Guwahati, Assam 781039, India;
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Borocci S, Grandinetti F, Sanna N. On the Proton-Bound Noble Gas Dimers (Ng-H-Ng) + and (Ng-H-Ng') + (Ng, Ng'= He-Xe): Relationships betweenStructure, Stability, and Bonding Character. Molecules 2021; 26:1305. [PMID: 33671081 DOI: 10.3390/molecules26051305] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 02/23/2021] [Accepted: 02/24/2021] [Indexed: 11/17/2022] Open
Abstract
The structure, stability, and bonding character of fifteen (Ng-H-Ng)+ and (Ng-H-Ng’)+ (Ng, Ng’ = He-Xe) compounds were explored by theoretical calculations performed at the coupled cluster level of theory. The nature of the stabilizing interactions was, in particular, assayed using a method recently proposed by the authors to classify the chemical bonds involving the noble-gas atoms. The bond distances and dissociation energies of the investigated ions fall in rather large intervals, and follow regular periodic trends, clearly referable to the difference between the proton affinity (PA) of the various Ng and Ng’. These variations are nicely correlated with the bonding situation of the (Ng-H-Ng)+ and (Ng-H-Ng’)+. The Ng-H and Ng’-H contacts range, in fact, between strong covalent bonds to weak, non-covalent interactions, and their regular variability clearly illustrates the peculiar capability of the noble gases to undergo interactions covering the entire spectrum of the chemical bond.
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Abstract
A new analytical potential energy surface (PES) has been constructed for the Ar2H+ system from a dataset consisting of a large number of ab initio energies computed using the coupled-cluster singles, doubles and perturbative triples method and aug-cc-pVQZ basis set. The long-range interaction is added to the diatomic potentials using a standard long range expansion form to better describe the asymptotic regions. The vibrational states for the most stable structures of the Ar2H+ system have been calculated, and few low lying states are assigned to quantum numbers. Reactive scattering studies have been performed for the Ar + Ar'H+ → Ar' + ArH+ proton exchange reaction on the newly generated PES. Reaction probability, cross sections, and rate constants are calculated for the Ar + Ar'H+(v = 0, j = 0) collisions within 0.01 eV-0.6 eV of relative translational energy using exact quantum dynamical simulations as well as quasiclassical trajectory (QCT) calculations. The effect of vibrational excitation of the reactants is also explored for the reaction. State averaged rate constants are calculated for the proton exchange reaction at different temperatures using the QCT method. The mechanistic pathways for the reaction are understood by analyzing the quasiclassical trajectories.
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Affiliation(s)
- Debasish Koner
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Tirupati, Karakambadi Road, Mangalam, Tirupati 517507, Andhra Pradesh, India
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Abstract
Starting from a model study of the collinear (H, H2) exchange reaction in 1959, the time-dependent quantum mechanical wave packet (TDQMWP) method has come a long way in dealing with systems as large as Cl + CH4. The fast Fourier transform method for evaluating the second order spatial derivative of the wave function and split-operator method or Chebyshev polynomial expansion for determining the time evolution of the wave function for the system have made the approach highly accurate from a practical point of view. The TDQMWP methodology has been able to predict state-to-state differential and integral reaction cross sections accurately, in agreement with available experimental results for three dimensional (H, H2) collisions, and identify reactive scattering resonances too. It has become a practical computational tool in predicting the observables for many A + BC exchange reactions in three dimensions and a number of larger systems. It is equally amenable to determining the bound and quasi-bound states for a variety of molecular systems. Just as it is able to deal with dissociative processes (without involving basis set expansion), it is able to deal with multi-mode nonadiabatic dynamics in multiple electronic states with equal ease. We present an overview of the method and its strength and limitations, citing examples largely from our own research groups.
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González-Lezana T, Bossion D, Scribano Y, Bhowmick S, Suleimanov YV. Dynamics of H + HeH +( v = 0, j = 0) → H 2+ + He: Insight on the Possible Complex-Forming Behavior of the Reaction. J Phys Chem A 2019; 123:10480-10489. [PMID: 31725286 DOI: 10.1021/acs.jpca.9b06122] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The H + HeH+→ He + H2+ reaction has been studied by means of a combination of theoretical approaches: a statistical quantum method (SQM), ring polymer molecular dynamics (RPMD), and the quasiclassical trajectory (QCT) method. Cross sections and rate constants have been calculated in an attempt to investigate the dynamics of the process. The comparison with previous calculations and experimental results reveals that despite the fact that statistical predictions seem to reproduce some of the overall observed features, the analysis at a more detailed state-to-state level shows noticeable deviations from a complex-forming dynamics. We find some differences in cross sections and rate constants obtained in the QCT calculation with a Gaussian binning procedure with respect to previous works in which the standard histogram binning was employed.
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Affiliation(s)
| | - Duncan Bossion
- Laboratoire Univers et Particules de Montpellier, UMR-CNRS 5299 , Université de Montpellier , 34095 Montpellier Cedex , France
| | - Yohann Scribano
- Laboratoire Univers et Particules de Montpellier, UMR-CNRS 5299 , Université de Montpellier , 34095 Montpellier Cedex , France
| | - Somnath Bhowmick
- Computation-based Science and Technology Research Center , The Cyprus Institute , 20 Konstantinou Kavafi Street , Nicosia 2121 , Cyprus
| | - Yury V Suleimanov
- Computation-based Science and Technology Research Center , The Cyprus Institute , 20 Konstantinou Kavafi Street , Nicosia 2121 , Cyprus
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Koner D, Barrios L, González-Lezana T, Panda AN. Scattering study of the Ne + NeH(+)(v0 = 0, j0 = 0) → NeH(+) + Ne reaction on an ab initio based analytical potential energy surface. J Chem Phys 2016; 144:034303. [PMID: 26801030 DOI: 10.1063/1.4939952] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Initial state selected dynamics of the Ne + NeH(+)(v0 = 0, j0 = 0) → NeH(+) + Ne reaction is investigated by quantum and statistical quantum mechanical (SQM) methods on the ground electronic state. The three-body ab initio energies on a set of suitably chosen grid points have been computed at CCSD(T)/aug-cc-PVQZ level and analytically fitted. The fitting of the diatomic potentials, computed at the same level of theory, is performed by spline interpolation. A collinear [NeHNe](+) structure lying 0.72 eV below the Ne + NeH(+) asymptote is found to be the most stable geometry for this system. Energies of low lying vibrational states have been computed for this stable complex. Reaction probabilities obtained from quantum calculations exhibit dense oscillatory structures, particularly in the low energy region and these get partially washed out in the integral cross section results. SQM predictions are devoid of oscillatory structures and remain close to 0.5 after the rise at the threshold thus giving a crude average description of the quantum probabilities. Statistical cross sections and rate constants are nevertheless in sufficiently good agreement with the quantum results to suggest an important role of a complex-forming dynamics for the title reaction.
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Affiliation(s)
- Debasish Koner
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781039, India
| | - Lizandra Barrios
- IFF-CSIC, Instituto de Física Fundamental, CSIC, Serrano 123, Madrid 28006, Spain
| | | | - Aditya N Panda
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781039, India
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Koner D, Barrios L, González-Lezana T, Panda AN. State-to-State Dynamics of the Ne + HeH(+) (v = 0, j = 0) → NeH(+)(v', j') + He Reaction. J Phys Chem A 2016; 120:4731-41. [PMID: 26943458 DOI: 10.1021/acs.jpca.5b11477] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The dynamics of the Ne + HeH(+)(v = 0, j = 0) → NeH(+)(v', j') + He reaction was analyzed in detail at the state-to-state level. A time-independent quantum mechanical (TIQM) method was applied to calculate rovibrational distributions and differential cross sections (DCSs), in comparison with quasi-classical trajectory and statistical quantum predictions. Possible changes in the dynamical mechanisms that define the process were also investigated as a function of the collision energy. At the lowest energy regime, the TIQM results produce a noticeably different cross section in comparison with previously reported time-dependent wave packet results. Although the statistical methods reproduce some dynamical features, especially as the energy increases, the marked preference for the forward scattering direction on the DCSs suggests that the reaction mainly follows a direct mechanism.
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Affiliation(s)
- Debasish Koner
- Department of Chemistry, Indian Institute of Technology , Guwahati 781039, India
| | - Lizandra Barrios
- Instituto de Física Fundamental, IFF-CSIC , Serrano 123, Madrid 28006, Spain
| | | | - Aditya N Panda
- Department of Chemistry, Indian Institute of Technology , Guwahati 781039, India
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