1
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Zhao H, Sun Z. Higher-Order Split Operator Schemes for Solving Tetratomic Reactions Using the Time-Dependent Wave Packet Method. J Phys Chem A 2024; 128:4911-4922. [PMID: 38847623 DOI: 10.1021/acs.jpca.4c01802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
In this work, using the time-dependent quantum wave packet method, quite a few typical higher-order split operators (HOSOs) were for the first time applied to calculate the tetratomic reactive scattering processes in the hyperspherical coordinate. It was found that the HOSOs were hardly efficient for a tetratomic reaction calculation, unlike those for a triatomic reactive scattering calculation. We proposed an efficient HOSO with a force gradient (denoted as 2G1 in the main text) for efficiently and accurately calculating a tetratomic reaction using the quantum wave packet method. Several typical tetratomic reactions, such as H2 + OH, HF + OH, and H2 + OH+, are calculated for demonstrating the effectiveness of the proposed 2G1 in terms of (product state-resolved) reaction probability and inelastic probability, by comparing with the performance of the previously reported various HOSOs. We suggest that the 2G1 propagator could be applied to efficiently calculate a general tetratomic reaction.
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Affiliation(s)
- Hailin Zhao
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P.R. China
| | - Zhigang Sun
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P.R. China
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2
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Kale SS, Kais S. Simulation of Chemical Reactions on a Quantum Computer. J Phys Chem Lett 2024; 15:5633-5642. [PMID: 38759104 DOI: 10.1021/acs.jpclett.4c01100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/19/2024]
Abstract
Studying chemical reactions, particularly in the gas phase, relies heavily on computing scattering matrix elements. These elements are essential for characterizing molecular reactions and accurately determining reaction probabilities. However, the intricate nature of quantum interactions poses challenges, necessitating the use of advanced mathematical models and computational approaches to tackle the inherent complexities. In this study, we develop and apply a quantum computing algorithm for the calculation of scattering matrix elements. In our approach, we employ the time-dependent method based on the Møller operator formulation where the S-matrix element between the respective reactant and product channels is determined through the time correlation function of the reactant and product Møller wavepackets. We successfully apply our quantum algorithm to calculate scattering matrix elements for 1D semi-infinite square well potential and on the colinear hydrogen exchange reaction. As we navigate the complexities of quantum interactions, this quantum algorithm is general and emerges as a promising avenue, shedding light on new possibilities for simulating chemical reactions on quantum computers.
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Affiliation(s)
- Sumit Suresh Kale
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Sabre Kais
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
- Department of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
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3
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Wang R, Zhao H, Sun Z. Reactant-Product Decoupling Technique Using the Intermediate Coordinate Method. J Phys Chem A 2024; 128:3726-3741. [PMID: 38666315 DOI: 10.1021/acs.jpca.4c01148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2024]
Abstract
Although the reactant-product decoupling (RPD) technique was proposed over two decades ago, it remains an efficient approach for calculating product state-resolved information on some simple direct reactions using the quantum wave packet method. In the past, usually the RPD technique employed the collocation method to transform the wave function between reactant and product arrangements, which requires quite large computational efforts. In this work, the intermediate coordinate (IC) method is employed to realize the RPD technique. Numerical examples demonstrate that this new IC RPD (IRPD) technique has superior computational efficiency compared with the original method employing the collocation method. Especially, the new IRPD technique significantly saves disk space and computer memory. To illustrate the features of our new method, the total reaction probabilities of the H + H2, H + Br2, and F + H2 reactions with J = 0 and the differential cross sections of the H + H2 and F + H2 reactions at a series of collision energy are calculated and presented. With this efficient and effective new RPD technique, the Li + HF reaction, which involves sharp resonances with long-range wave functions in the van der Waals wells in both the reactant and product arrangements, is also calculated with several J at the product state-resolved level to reveal the ability of the RPD technique for describing resonance wave functions. With these numerical examples, it is found that, for the reaction with resonances, the RPD approach should be applied carefully. Otherwise, it is very possible that the resonances could disappear with the application of the RPD technique.
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Affiliation(s)
- Ransheng Wang
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hailin Zhao
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Zhigang Sun
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
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4
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Gong Q, Man Q, Zhao J, Li Y, Dou M, Wang Q, Wu YC, Guo GP. Simulating chemical reaction dynamics on quantum computer. J Chem Phys 2024; 160:124103. [PMID: 38526102 DOI: 10.1063/5.0192036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 03/06/2024] [Indexed: 03/26/2024] Open
Abstract
The electronic energies of molecules have been successfully evaluated on quantum computers. However, more attention is paid to the dynamics simulation of molecules in practical applications. Based on the variational quantum eigensolver (VQE) algorithm, Fedorov et al. proposed a correlated sampling (CS) method and demonstrated the vibrational dynamics of H2 molecules [J. Chem. Phys. 154, 164103 (2021)]. In this study, we have developed a quantum approach by extending the CS method based on the VQE algorithm (labeled eCS-VQE) for simulating chemical reaction dynamics. First, the CS method is extended to the three-dimensional cases for calculation of first-order energy gradients, and then, it is further generalized to calculate the second-order gradients of energies. By calculating atomic forces and vibrational frequencies for H2, LiH, H+ + H2, and Cl- + CH3Cl systems, we have seen that the approach has achieved the CCSD level of accuracy. Thus, we have simulated dynamics processes for two typical chemical reactions, hydrogen exchange and chlorine substitution, and obtained high-precision reaction dynamics trajectories consistent with the classical methods. Our eCS-VQE approach, as measurement expectations and ground-state wave functions can be reused, is less demanding in quantum computing resources and is, therefore, a feasible means for the dynamics simulation of chemical reactions on the current noisy intermediate-scale quantum-era quantum devices.
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Affiliation(s)
- Qiankun Gong
- Origin Quantum Computing Company Limited, Hefei, Anhui 230026, China
| | - Qingmin Man
- Origin Quantum Computing Company Limited, Hefei, Anhui 230026, China
| | - Jianyu Zhao
- Origin Quantum Computing Company Limited, Hefei, Anhui 230026, China
| | - Ye Li
- Origin Quantum Computing Company Limited, Hefei, Anhui 230026, China
| | - Menghan Dou
- Origin Quantum Computing Company Limited, Hefei, Anhui 230026, China
| | - Qingchun Wang
- Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, Anhui 230088, China
| | - Yu-Chun Wu
- Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, Anhui 230088, China
- CAS Key Laboratory of Quantum Information, School of Physics, University of Science and Technology of China, Hefei 230026, China
| | - Guo-Ping Guo
- Origin Quantum Computing Company Limited, Hefei, Anhui 230026, China
- Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, Anhui 230088, China
- CAS Key Laboratory of Quantum Information, School of Physics, University of Science and Technology of China, Hefei 230026, China
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5
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Zhao H, Sun Z. Theoretical Development of the Interaction-Asymptotic Region Decomposition Method for Tetratomic Reactive Scattering. J Chem Theory Comput 2024; 20:1802-1810. [PMID: 38262035 DOI: 10.1021/acs.jctc.3c01368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2024]
Abstract
An accurate and efficient time-dependent wave packet method is proposed for solving the product state-resolved reaction probabilities of the tetratomic reactive system. In this method, the entire scattering process is divided into the interaction region and multiple asymptotic regions, sharing the same spirit as the interaction-asymptotic region decomposition (IARD) approach in a triatomic reactive scattering process. The hyperspherical coordinate is adopted in the interaction region, while the corresponding Jacobi coordinate is employed in each asymptotic region. Therefore, in this IARD method, the "coordinate problem", the difficulty of expressing the wave function in the entire region using a single coordinate system, can be effectively avoided, and only a very small number of the grid points (or the basis functions) are required. For the numerical illustration, the typical tetratomic reaction H2 + OH with zero total angular momentum is calculated, and compared with other quantum wave packet methods. Our proposed IARD method for the tetratomic reactive system is much more efficient and accurate.
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Affiliation(s)
- Hailin Zhao
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, P.R. China 116023
| | - Zhigang Sun
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, P.R. China 116023
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6
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Fu B, Zhang DH. Accurate fundamental invariant-neural network representation of ab initio potential energy surfaces. Natl Sci Rev 2023; 10:nwad321. [PMID: 38274241 PMCID: PMC10808953 DOI: 10.1093/nsr/nwad321] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 11/01/2023] [Accepted: 11/02/2023] [Indexed: 01/27/2024] Open
Abstract
Highly accurate potential energy surfaces are critically important for chemical reaction dynamics. The large number of degrees of freedom and the intricate symmetry adaption pose a big challenge to accurately representing potential energy surfaces (PESs) for polyatomic reactions. Recently, our group has made substantial progress in this direction by developing the fundamental invariant-neural network (FI-NN) approach. Here, we review these advances, demonstrating that the FI-NN approach can represent highly accurate, global, full-dimensional PESs for reactive systems with even more than 10 atoms. These multi-channel reactions typically involve many intermediates, transition states, and products. The complexity and ruggedness of this potential energy landscape present even greater challenges for full-dimensional PES representation. These PESs exhibit a high level of complexity, molecular size, and accuracy of fit. Dynamics simulations based on these PESs have unveiled intriguing and novel reaction mechanisms, providing deep insights into the intricate dynamics involved in combustion, atmospheric, and organic chemistry.
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Affiliation(s)
- Bina Fu
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- Hefei National Laboratory, Hefei 230088, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dong H Zhang
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- Hefei National Laboratory, Hefei 230088, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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7
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Shu Y, Varga Z, Zhang D, Truhlar DG. ChemPotPy: A Python Library for Analytic Representations of Potential Energy Surfaces and Diabatic Potential Energy Matrices. J Phys Chem A 2023; 127:9635-9640. [PMID: 37916790 DOI: 10.1021/acs.jpca.3c05899] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
Constructing analytic representations of global and semiglobal potential energy surfaces is difficult and can be laborious, and it is even harder when one needs coupled potential energy surfaces and their electronically nonadiabatic couplings. When accomplished, however, the resulting potential functions are a valuable resource. To facilitate the convenient use of potentials that have been developed, we provide a collection of existing surfaces in a library with consistent units and formats. A potential energy surface library of this type, namely PotLib, was built more than 20 years ago. However, that library only provided pristine Fortran subroutines for each potential energy surface, and therefore, it is not as user-friendly as would be desirable. Here, we report the creation of ChemPotPy, a CHEMical library of POTential energy surfaces in PYthon. ChemPotPy is a user-friendly library for analytic representation of single-state and multistate potential energy surfaces and couplings. A given entry in the library contains an analytic potential energy function or analytic functions for a set of coupled potential energy surfaces, and depending on the case, it may also include analytic or numerical gradients, nonadiabatic coupling vectors, and/or diabatic potential energy matrices and their gradients. Only three inputs, namely, the chemical formula of the system, the name of the potential energy surface or surface set, and the Cartesian geometry, are required. ChemPotPy uses the same units for input and output quantities of all surfaces and surface sets to facilitate general interfaces with the dynamics programs. The initial version of the library contains 338 entries, and we anticipate that more will be added in the future.
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Affiliation(s)
- Yinan Shu
- Department of Chemistry, Chemical Theory Center and Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
| | - Zoltan Varga
- Department of Chemistry, Chemical Theory Center and Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
| | - Dayou Zhang
- Department of Chemistry, Chemical Theory Center and Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
| | - Donald G Truhlar
- Department of Chemistry, Chemical Theory Center and Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
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8
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Song H, Guo H. Theoretical Insights into the Dynamics of Gas-Phase Bimolecular Reactions with Submerged Barriers. ACS PHYSICAL CHEMISTRY AU 2023; 3:406-418. [PMID: 37780541 PMCID: PMC10540288 DOI: 10.1021/acsphyschemau.3c00009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 06/02/2023] [Accepted: 06/06/2023] [Indexed: 10/03/2023]
Abstract
Much attention has been paid to the dynamics of both activated gas-phase bimolecular reactions, which feature monotonically increasing integral cross sections and Arrhenius kinetics, and their barrierless capture counterparts, which manifest monotonically decreasing integral cross sections and negative temperature dependence of the rate coefficients. In this Perspective, we focus on the dynamics of gas-phase bimolecular reactions with submerged barriers, which often involve radicals or ions and are prevalent in combustion, atmospheric chemistry, astrochemistry, and plasma chemistry. The temperature dependence of the rate coefficients for such reactions is often non-Arrhenius and complex, and the corresponding dynamics may also be quite different from those with significant barriers or those completely dominated by capture. Recent experimental and theoretical studies of such reactions, particularly at relatively low temperatures or collision energies, have revealed interesting dynamical behaviors, which are discussed here. The new knowledge enriches our understanding of the dynamics of these unusual reactions.
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Affiliation(s)
- Hongwei Song
- State
Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Innovation Academy for Precision Measurement Science
and Technology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Hua Guo
- Department
of Chemistry and Chemical Biology, University
of New Mexico, Albuquerque, New Mexico 87131, United States
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9
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Iyengar SS, Kumar A, Saha D, Sabry A. Synthesis of Hidden Subgroup Quantum Algorithms and Quantum Chemical Dynamics. J Chem Theory Comput 2023; 19:6082-6092. [PMID: 37703187 DOI: 10.1021/acs.jctc.3c00404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/15/2023]
Abstract
We describe a general formalism for quantum dynamics and show how this formalism subsumes several quantum algorithms, including the Deutsch, Deutsch-Jozsa, Bernstein-Vazirani, Simon, and Shor algorithms as well as the conventional approach to quantum dynamics based on tensor networks. The common framework exposes similarities among quantum algorithms and natural quantum phenomena: we illustrate this connection by showing how the correlated behavior of protons in water wire systems that are common in many biological and materials systems parallels the structure of Shor's algorithm.
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Affiliation(s)
- Srinivasan S Iyengar
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102, United States
- Quantum Science and Engineering Center (QSEc), Indiana University, Bloomington, Indiana 47405-7102, United States
| | - Anup Kumar
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102, United States
| | - Debadrita Saha
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102, United States
| | - Amr Sabry
- Quantum Science and Engineering Center (QSEc), Indiana University, Bloomington, Indiana 47405-7102, United States
- Department of Computer Science, Luddy School of Informatics, Computing, and Engineering, Indiana University, Bloomington, Indiana 47405-7102, United States
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10
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Yang D, Chai S, Xie D, Guo H. ABC+D: A time-independent coupled-channel quantum dynamics program for elastic and ro-vibrational inelastic scattering between atoms and triatomic molecules in full dimensionality. J Chem Phys 2023; 158:054801. [PMID: 36754781 DOI: 10.1063/5.0137628] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
We discuss the details of a time-independent quantum mechanical method and its implementation for full-dimensional non-reactive scattering between a closed-shell triatomic molecule and a closed-shell atom. By solving the time-independent Schrödinger equation within the coupled-channel framework using a log-derivative method, the state-to-state scattering matrix (S-matrix) can be determined for inelastic scattering involving both the rotational and vibrational modes of the molecule. Various approximations are also implemented. The ABC+D code provides an important platform for understanding an array of physical phenomena involving collisions between atoms and molecules.
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Affiliation(s)
- Dongzheng Yang
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Shijie Chai
- Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Daiqian Xie
- Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Hua Guo
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA
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11
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Houston PL, Nandi A, Bowman JM. A Machine Learning Approach for Rate Constants. III. Application to the Cl( 2P) + CH 4 → CH 3 + HCl Reaction. J Phys Chem A 2022; 126:5672-5679. [PMID: 35960874 DOI: 10.1021/acs.jpca.2c04376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The temperature dependence of the thermal rate constant for the reaction Cl(3P) + CH4 → HCl + CH3 is calculated using a Gaussian Process machine learning (ML) approach to train on and predict thermal rate constants over a large temperature range. Following procedures developed in two previous reports, we use a training data set of approximately 40 reaction/potential surface combinations, each of which is used to calculate the corresponding database of rate constant at approximately eight temperatures. For the current application, we train on the entire data set and then predict the temperature dependence of the title reaction employing a "split" data set for correction at low and high temperatures to capture both tunneling and recrossing. The results are an improvement on recent RPMD calculations compared to accurate quantum ones, using the same high-level ab initio potential energy surface. Both tunneling at low temperatures and significant recrossing at high temperatures are observed to influence the rate constants. The recrossing effects, which are not described by TST and even sophisticated tunneling corrections, do appear in experiment at temperatures above around 600 K. The ML results describe these effects and in fact merge at 600 K with RPMD results (which can describe recrossing), and both are close to experiment at the highest experimental temperatures. These results are in accord with a recent high-level experiment-theory study of this reaction.
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Affiliation(s)
- Paul L Houston
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States.,Department of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Apurba Nandi
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Joel M Bowman
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
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12
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Buren B, Chen M. Stereodynamics-Controlled Product Branching in the Nonadiabatic H + NaD → Na(3s, 3p) + HD Reaction at Low Temperatures. J Phys Chem A 2022; 126:2453-2462. [PMID: 35434992 DOI: 10.1021/acs.jpca.2c00114] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Nonadiabatic processes play an important role at energies near or higher than conical intersection of adiabatic potential energy surfaces in chemical reactions. In this work, dynamics of the nonadiabatic H + NaD reaction at low temperatures are studied by using the quantum wave packet method based on an improved L-shaped grid. The nonadiabatic H + NaD reaction has two exothermic reaction channels: Na(3s) + HD and Na(3p) + HD; the latter can only occur via nonadiabatic transition. The dynamics results show that the product branching of the H + NaD reaction at collision energies ranging from 20 to 80 cm-1 is controlled by stereodynamics. The Na(3s) and Na(3p) reaction channels occur through collinear collision and side-on collision, respectively. When the collision energy is lower than 20 cm-1, the resonance-mediated reaction mechanism is dominant in both the Na(3s) and Na(3p) reaction channels.
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Affiliation(s)
- Bayaer Buren
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian 116024, PR China
| | - Maodu Chen
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian 116024, PR China
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13
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Song H, Xie W, Zhang C, Yang M. Toward a Comprehensive Understanding of Mode-Specific Dynamics of Polyatomic Reactions: A Full-Dimensional Quantum Dynamics Study of the H + NH 3 Reaction. J Phys Chem A 2022; 126:663-669. [PMID: 35080397 DOI: 10.1021/acs.jpca.1c08399] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mode specificity not only sheds light on reaction dynamics but also opens the door for chemical reaction control. This work reports a state-of-the-art full-dimensional quantum dynamics study on the prototypical hydrogen abstraction reaction of hydrogen with ammonia, which serves as a benchmark for advancing our fundamental understanding of polyatomic reaction dynamics. By taking advantage of the (3 + 1) Radau-Jacobi coordinates, the bond-specific probabilities are resolved with the reactant NH3 initiated from either a non-degenerate or degenerate stretching vibrational state. The observed different atom-specific abstraction probabilities from individual states of the degenerate pair are rationalized in the local mode representation according to the different vibrational energy deposited in each N-H bond. It is verified that the three H atoms in NH3 have the same abstraction probability as that from the degenerate pair and the linear combination of the degenerate pair gives the same reaction probability. In addition, the symmetric and asymmetric stretching modes of the reactant NH3 have comparable efficacies on driving the reaction.
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Affiliation(s)
- Hongwei Song
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Weiyu Xie
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China
| | - Chaoyang Zhang
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China
| | - Minghui Yang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China.,Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430071, China
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14
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Non-adiabatic Couplings Induced Complex-forming Mechanism in the H+MgH +→Mg ++H 2 Reaction. CHINESE J CHEM PHYS 2022. [DOI: 10.1063/1674-0068/cjcp2111237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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15
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Buren B, Chen M, Sun Z, Guo H. Quantum Wave Packet Treatment of Cold Nonadiabatic Reactive Scattering at the State-To-State Level. J Phys Chem A 2021; 125:10111-10120. [PMID: 34767377 DOI: 10.1021/acs.jpca.1c08105] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cold and ultracold collisions are dominated by quantum effects, such as resonances, tunneling, and nonadiabatic transitions between different electronic states. Due to the extremely long de Broglie wavelength in such processes, quantum reactive scattering is most conveniently characterized using the time-independent close-coupling (TICC) methods. However, the TICC approach is difficult for systems with a large number of channels because of its steep numerical scaling laws. Here, a recently proposed quantum wave packet (WP) approach for solving adiabatic reactive scattering problems at low collision energies is extended to include nonadiabatic transitions. To impose the outgoing boundary conditions, the total scattering wavefunction is split into three parts, the interaction, the asymptotic, and the long-range regions. Each region is associated with a different set of basis functions, which could be optimized separately. In this way, an extremely long grid can be used to accommodate the characteristic long de Broglie wavelengths in the scattering coordinate. The better numerical scaling laws of the WP approach have the potential for handling larger nonadiabatic reactive systems at low temperatures in the future.
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Affiliation(s)
- Bayaer Buren
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian 116024, China.,Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
| | - Maodu Chen
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian 116024, China
| | - Zhigang Sun
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Hua Guo
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
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16
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Guan Y, Xie C, Yarkony DR, Guo H. High-fidelity first principles nonadiabaticity: diabatization, analytic representation of global diabatic potential energy matrices, and quantum dynamics. Phys Chem Chem Phys 2021; 23:24962-24983. [PMID: 34473156 DOI: 10.1039/d1cp03008f] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Nonadiabatic dynamics, which goes beyond the Born-Oppenheimer approximation, has increasingly been shown to play an important role in chemical processes, particularly those involving electronically excited states. Understanding multistate dynamics requires rigorous quantum characterization of both electronic and nuclear motion. However, such first principles treatments of multi-dimensional systems have so far been rather limited due to the lack of accurate coupled potential energy surfaces and difficulties associated with quantum dynamics. In this Perspective, we review recent advances in developing high-fidelity analytical diabatic potential energy matrices for quantum dynamical investigations of polyatomic uni- and bi-molecular nonadiabatic processes, by machine learning of high-level ab initio data. Special attention is paid to methods of diabatization, high fidelity construction of multi-state coupled potential energy surfaces and property surfaces, as well as quantum mechanical characterization of nonadiabatic nuclear dynamics. To illustrate the tremendous progress made by these new developments, several examples are discussed, in which direct comparison with quantum state resolved measurements led to either confirmation of the observation or sometimes reinterpretation of the experimental data. The insights gained in these prototypical systems greatly advance our understanding of nonadiabatic dynamics in chemical systems.
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Affiliation(s)
- Yafu Guan
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, USA.
| | - Changjian Xie
- Institute of Modern Physics, Northwest University, Xi'an, Shaanxi 710069, China.
| | - David R Yarkony
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, USA.
| | - Hua Guo
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico, 87131, USA.
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17
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Konings M, Desrousseaux B, Lique F, Loreau J. Benchmarking an improved statistical adiabatic channel model for competing inelastic and reactive processes. J Chem Phys 2021; 155:104302. [PMID: 34525820 DOI: 10.1063/5.0062388] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Inelastic collisions and elementary chemical reactions proceeding through the formation and subsequent decay of an intermediate collision complex, with an associated deep well on the potential energy surface, pose a challenge for accurate fully quantum mechanical approaches, such as the close-coupling method. In this study, we report on the theoretical prediction of temperature-dependent state-to-state rate coefficients for these complex-mode processes, using a statistical quantum method. This statistical adiabatic channel model is benchmarked by a direct comparison using accurate rate coefficients from the literature for a number of systems (H2 + H+, HD + H+, SH+ + H, and CH+ + H) of interest in astrochemistry and astrophysics. For all of the systems considered, an error of less than factor 2 was found, at least for the dominant transitions and at low temperatures, which is sufficiently accurate for applications in the above mentioned disciplines.
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Affiliation(s)
- Maarten Konings
- KU Leuven, Division of Quantum Chemistry and Physical Chemistry, Department of Chemistry, Celestijnenlaan 200F, 3001 Leuven, Belgium
| | - Benjamin Desrousseaux
- Université de Rennes 1, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
| | - François Lique
- Université de Rennes 1, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
| | - Jérôme Loreau
- KU Leuven, Division of Quantum Chemistry and Physical Chemistry, Department of Chemistry, Celestijnenlaan 200F, 3001 Leuven, Belgium
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18
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Hermsmeier R, Kłos J, Kotochigova S, Tscherbul TV. Quantum Spin State Selectivity and Magnetic Tuning of Ultracold Chemical Reactions of Triplet Alkali-Metal Dimers with Alkali-Metal Atoms. PHYSICAL REVIEW LETTERS 2021; 127:103402. [PMID: 34533330 DOI: 10.1103/physrevlett.127.103402] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 06/29/2021] [Accepted: 07/28/2021] [Indexed: 06/13/2023]
Abstract
We demonstrate that it is possible to efficiently control ultracold chemical reactions of alkali-metal atoms colliding with open-shell alkali-metal dimers in their metastable triplet states by choosing the internal hyperfine and rovibrational states of the reactants as well as by inducing magnetic Feshbach resonances with an external magnetic field. We base these conclusions on coupled-channel statistical calculations that include the effects of hyperfine contact and magnetic-field-induced Zeeman interactions on ultracold chemical reactions of hyperfine-resolved ground-state Na and the triplet NaLi(a^{3}Σ^{+}) producing singlet Na_{2}(^{1}Σ_{g}^{+}) and a Li atom. We find that the reaction rates are sensitive to the initial hyperfine states of the reactants. The chemical reaction of fully spin-polarized, high-spin states of rotationless NaLi(a^{3}Σ^{+},v=0,N=0) molecules with fully spin-polarized Na is suppressed by a factor of 10-100 compared to that of unpolarized reactants. We interpret these findings within the adiabatic state model, which treats the reaction as a sequence of nonadiabatic transitions between the initial nonreactive high-spin state and the final low-spin states of the reaction complex. In addition, we show that magnetic Feshbach resonances can similarly change reaction rate coefficients by several orders of magnitude. Some of these resonances are due to resonant trimer bound states dissociating to the N=2 rotational state of NaLi(a^{3}Σ^{+},v=0) and would thus exist in systems without hyperfine interactions.
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Affiliation(s)
| | - Jacek Kłos
- Department of Physics, Joint Quantum Institute, University of Maryland College Park, College Park, Maryland 20742, USA
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA
| | | | - Timur V Tscherbul
- Department of Physics, University of Nevada, Reno, Nevada 89557, USA
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19
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Yang D, Xie D, Guo H. A Time-Independent Quantum Approach to Ro-vibrationally Inelastic Scattering between Atoms and Triatomic Molecules. J Phys Chem A 2021; 125:6864-6871. [PMID: 34342998 DOI: 10.1021/acs.jpca.1c05237] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A full-dimensional time-independent quantum mechanical theory for ro-vibrationally inelastic scattering of triatomic molecules with atoms is formulated. The Jacobi-Radau coordinate system used in the calculation allows not only a near perfect description of the vibrational problem but also the adaptation of the exchange symmetry for A2B type triatoms. The S-matrix elements are obtained by solving the close-coupling equations with contracted basis using the log-derivative method. This method is applied to the inelastic scattering of the water molecule by a chlorine atom, which sheds light on the energy gap law in energy transfer in atom-triatom collisions.
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Affiliation(s)
- Dongzheng Yang
- Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Daiqian Xie
- Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Hua Guo
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
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20
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Fang JH, Fan WB, Yang H, Song JN, Li YL. Rate coefficients and kinetic isotope effects of Cl+XCl→XCl+Cl (X=H, D, Mu) reactions from ring polymer molecular dynamics. CHINESE J CHEM PHYS 2021. [DOI: 10.1063/1674-0068/cjcp2007117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Jun-hua Fang
- Department of Chemistry, Shanghai University, Shanghai 200444, China
| | - Wen-bin Fan
- Department of Physics, International Center for Quantum and Molecular Structures, and Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai 200444, China
| | - Hui Yang
- Department of Physics, International Center for Quantum and Molecular Structures, and Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai 200444, China
| | - Jia-ning Song
- Department of Physics, International Center for Quantum and Molecular Structures, and Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai 200444, China
| | - Yong-le Li
- Department of Physics, International Center for Quantum and Molecular Structures, and Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai 200444, China
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21
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Abstract
In this article, we review nonadiabatic molecular dynamics (NAMD) methods for modeling spin-crossover transitions. First, we discuss different representations of electronic states employed in the grid-based and direct NAMD simulations. The nature of interstate couplings in different representations is highlighted, with the main focus on nonadiabatic and spin-orbit couplings. Second, we describe three NAMD methods that have been used to simulate spin-crossover dynamics, including trajectory surface hopping, ab initio multiple spawning, and multiconfiguration time-dependent Hartree. Some aspects of employing different electronic structure methods to obtain information about potential energy surfaces and interstate couplings for NAMD simulations are also discussed. Third, representative applications of NAMD to spin crossovers in molecular systems of different sizes and complexities are highlighted. Finally, we pose several fundamental questions related to spin-dependent processes. These questions should be possible to address with future methodological developments in NAMD.
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Affiliation(s)
- Saikat Mukherjee
- Institut de Chimie Radicalaire, CNRS 7273, Aix-Marseille University, 13013 Marseille, France;
| | - Dmitry A Fedorov
- Oak Ridge Associated Universities, Oak Ridge, Tennessee 37830, USA;
| | - Sergey A Varganov
- Department of Chemistry, University of Nevada, Reno, Nevada 89557-0216, USA;
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22
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Yang H, Fan WB, Fang JH, Song J, Li Y. Rate coefficients of roaming reaction H+MgH using ring polymer molecular dynamics. CHINESE J CHEM PHYS 2021. [DOI: 10.1063/1674-0068/cjcp2007121] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Hui Yang
- Department of Physics, International Center for Quantum and Molecular Structures, and Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai 200444, China
| | - Wen-bin Fan
- Department of Physics, International Center for Quantum and Molecular Structures, and Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai 200444, China
| | - Jun-hua Fang
- Department of Chemistry, Shanghai University, Shanghai 200444, China
| | - Jianing Song
- Department of Physics, International Center for Quantum and Molecular Structures, and Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai 200444, China
| | - Yongle Li
- Department of Physics, International Center for Quantum and Molecular Structures, and Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai 200444, China
- Devision of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena 91125, USA
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23
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Zhao H, Xie D, Sun Z. Interaction-Asymptotic Region Decomposition Method for a Triatomic Reactive Scattering with Symmetry Adoption. J Phys Chem A 2021; 125:2460-2471. [DOI: 10.1021/acs.jpca.0c11438] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hailin Zhao
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- Center for Advanced Chemical Physics and 2011 Frontier Centre for Quantum Science and Technology, University of Science and Technology of China, 96 Jinzhai Road, Hefei 230026, China
| | - Daiqian Xie
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Zhigang Sun
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- Center for Advanced Chemical Physics and 2011 Frontier Centre for Quantum Science and Technology, University of Science and Technology of China, 96 Jinzhai Road, Hefei 230026, China
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24
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Bowen KP, Hillenbrand PM, Liévin J, Savin DW, Urbain X. Dynamics of the isotope exchange reaction of D with H 3 +, H 2D +, and D 2H . J Chem Phys 2021; 154:084307. [PMID: 33639774 DOI: 10.1063/5.0038434] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have measured the merged-beams rate coefficient for the titular isotope exchange reactions as a function of the relative collision energy in the range of ∼3 meV-10 eV. The results appear to scale with the number of available sites for deuteration. We have performed extensive theoretical calculations to characterize the zero-point energy corrected reaction path. Vibrationally adiabatic minimum energy paths were obtained using a combination of unrestricted quadratic configuration interaction of single and double excitations and internally contracted multireference configuration interaction calculations. The resulting barrier height, ranging from 68 meV to 89 meV, together with the various asymptotes that may be reached in the collision, was used in a classical over-the-barrier model. All competing endoergic reaction channels were taken into account using a flux reduction factor. This model reproduces all three experimental sets quite satisfactorily. In order to generate thermal rate coefficients down to 10 K, the internal excitation energy distribution of each H3 + isotopologue is evaluated level by level using available line lists and accurate spectroscopic parameters. Tunneling is accounted for by a direct inclusion of the exact quantum tunneling probability in the evaluation of the cross section. We derive a thermal rate coefficient of <1×10-12 cm3 s-1 for temperatures below 44 K, 86 K, and 139 K for the reaction of D with H3 +, H2D+, and D2H+, respectively, with tunneling effects included. The derived thermal rate coefficients exceed the ring polymer molecular dynamics prediction of Bulut et al. [J. Phys. Chem. A 123, 8766 (2019)] at all temperatures.
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Affiliation(s)
- K P Bowen
- Columbia Astrophysics Laboratory, Columbia University, New York, New York 10027, USA
| | - P-M Hillenbrand
- Columbia Astrophysics Laboratory, Columbia University, New York, New York 10027, USA
| | - J Liévin
- Spectroscopy, Quantum Chemistry and Atmospheric Remote Sensing (SQUARES), Université Libre de Bruxelles, B-1050 Brussels, Belgium
| | - D W Savin
- Columbia Astrophysics Laboratory, Columbia University, New York, New York 10027, USA
| | - X Urbain
- Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
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25
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Zhao H, Xie D, Sun Z. Interaction-Asymptotic Region Decomposition Method for an Insertion Reaction: Application to the S( 1D) + H 2 Reaction. J Phys Chem A 2021; 125:2007-2018. [PMID: 33625216 DOI: 10.1021/acs.jpca.1c00140] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
With adjusting principal axes hyperspherical (APH) coordinate in the interaction region, and the Jacobi coordinates in the asymptotic regions, an efficient multidomain interaction-asymptotic region decomposition (IARD) method has been developed to solve the "coordinate problem" in a product-state-resolved reactive scattering calculation using the quantum wave packet method. Although the APH coordinate treats with all three channels equally, and is efficient for describing the interaction region for some direct reactions, it is inefficient for describing the insertion-type reaction due to the singularity problem, such as the S(1D) + H2 reaction. To deal with this issue, in this work, the channel-dependent Delves hyperspherical (DH) coordinate is proposed to describe the interaction region using the IARD method. The proposed DH-IARD method was applied to calculate the product-state-resolved reaction probabilities of the H + HD reaction, and the differential and integral cross sections of the typical insertion reaction S(1D) + H2. It is found that the new DH-IARD method is much more efficient than the previous APH-IARD method for dealing with insertion reactions. The partial wave resonance structures were observed in the integral cross section. It is found that at a low collision energy, the position of the initial wave packet has to be put far away. Otherwise, the partial wave resonance structures could not be correctly reproduced due to the reef well arising with a large total angular momentum J.
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Affiliation(s)
- Hailin Zhao
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.,State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.,Center for Advanced Chemical Physics and 2011 Frontier Centre for Quantum Science and Technology, University of Science and Technology of China, 96 Jinzhai Road, Hefei 230026, China
| | - Daiqian Xie
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Zhigang Sun
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.,Center for Advanced Chemical Physics and 2011 Frontier Centre for Quantum Science and Technology, University of Science and Technology of China, 96 Jinzhai Road, Hefei 230026, China
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26
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Sathyamurthy N, Mahapatra S. Time-dependent quantum mechanical wave packet dynamics. Phys Chem Chem Phys 2020; 23:7586-7614. [PMID: 33306771 DOI: 10.1039/d0cp03929b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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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27
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Hillenbrand PM, Bowen KP, Dayou F, Miller KA, de Ruette N, Urbain X, Savin DW. Experimental study of the proton-transfer reaction C + H 2+ → CH + + H and its isotopic variant (D 2+). Phys Chem Chem Phys 2020; 22:27364-27384. [PMID: 33231243 DOI: 10.1039/d0cp04810k] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report absolute integral cross section (ICS) measurements using a dual-source merged-fast-beams apparatus to study the titular reactions over the relative translational energy range of Er ∼ 0.01-10 eV. We used photodetachment of C- to produce a pure beam of atomic C in the ground electronic 3P term, with statistically populated fine-structure levels. The H2+ and D2+ were formed in an electron impact ionization source, with well known vibrational and rotational distributions. The experimental work is complemented by a theoretical study of the CH2+ electronic system in the reactant and product channels, which helps to clarify the possible reaction mechanisms underlying the ICS measurements. Our measurements provide evidence that the reactions are barrierless and exoergic. They also indicate the apparent absence of an intermolecular isotope effect, to within the total experimental uncertainties. Capture models, taking into account either the charge-induced dipole interaction potential or the combined charge-quadrupole and charge-induced dipole interaction potentials, produce reaction cross sections that lie a factor of ∼4 above the experimental results. Based on our theoretical study, we hypothesize that the reaction is most likely to proceed adiabatically through the 14A' and 14A'' states of CH2+via the reaction C(3P) + H2+(2Σ+g) → CH+(3Π) + H(2S). We also hypothesize that at low collision energies only H2+(v ≤ 2) and D2+(v ≤ 3) contribute to the titular reactions, due to the onset of dissociative charge transfer for higher vibrational v levels. Incorporating these assumptions into the capture models brings them into better agreement with the experimental results. Still, for energies ⪅0.1 eV where capture models are most relevant, the modified charge-induced dipole model yields reaction cross sections with an incorrect energy dependence and lying ∼10% below the experimental results. The capture cross section obtained from the combined charge-quadrupole and charge-induced dipole model better matches the measured energy dependence but lies ∼30-50% above the experimental results. These findings provide important guidance for future quasiclassical trajectory and quantum mechanical treatments of this reaction.
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28
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Zhao B, Manthe U. Eight-Dimensional Wave Packet Dynamics Within the Quantum Transition-State Framework: State-to-State Reactive Scattering for H2 + CH3 ⇆ H + CH4. J Phys Chem A 2020; 124:9400-9412. [DOI: 10.1021/acs.jpca.0c08461] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Bin Zhao
- Theoretische Chemie, Fakultät für Chemie, Universität Bielefeld, Universitätsstraße 25, D-33615 Bielefeld, Germany
| | - Uwe Manthe
- Theoretische Chemie, Fakultät für Chemie, Universität Bielefeld, Universitätsstraße 25, D-33615 Bielefeld, Germany
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29
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Li J, Zhao B, Xie D, Guo H. Advances and New Challenges to Bimolecular Reaction Dynamics Theory. J Phys Chem Lett 2020; 11:8844-8860. [PMID: 32970441 DOI: 10.1021/acs.jpclett.0c02501] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Dynamics of bimolecular reactions in the gas phase are of foundational importance in combustion, atmospheric chemistry, interstellar chemistry, and plasma chemistry. These collision-induced chemical transformations are a sensitive probe of the underlying potential energy surface(s). Despite tremendous progress in past decades, our understanding is still not complete. In this Perspective, we survey the recent advances in theoretical characterization of bimolecular reaction dynamics, stimulated by new experimental observations, and identify key new challenges.
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Affiliation(s)
- Jun Li
- School of Chemistry and Chemical Engineering & Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing 401331, China
| | - Bin Zhao
- Theoretische Chemie, Fakultät für Chemie, Universität Bielefeld, Universitätsstraße 25, D-33615 Bielefeld, Germany
| | - Daiqian Xie
- Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Hua Guo
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, United States
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30
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Lepetit B. Computation and analysis of bound vibrational spectra of the neon tetramer using row orthonormal hyperspherical coordinates. J Chem Phys 2020; 153:104302. [PMID: 32933308 DOI: 10.1063/5.0022655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
This paper presents the first implementation of the row-orthonormal hyperspherical coordinate formalism for the computation of the vibrational spectrum of a tetratomic system. The wavefunction of Ne4 is expanded on a large basis set of hyperspherical harmonics generated numerically. This method not only provides spectra with reasonable accuracy, but also gives physical insight into the vibrational dynamics of the system. The characteristics of the spectra are related to the symmetry and localization of the wavefunction in configuration space.
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Affiliation(s)
- Bruno Lepetit
- Laboratoire Collisions, Agrégats, Réactivité, UMR 5589, CNRS-Université Paul Sabatier Toulouse 3, IRSAMC, 31062 Toulouse Cedex 9, France
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31
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Laude G, Calderini D, Welsch R, Richardson JO. Calculations of quantum tunnelling rates for muonium reactions with methane, ethane and propane. Phys Chem Chem Phys 2020; 22:16843-16854. [PMID: 32666960 DOI: 10.1039/d0cp01346c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Thermal rate constants for Mu + CH4, Mu + C2H6 and Mu + C3H8 and their equivalent reactions with H were evaluated with ab initio instanton rate theory. The potential-energy surfaces are fitted using Gaussian process regression to high-level electronic-structure calculations evaluated around the tunnelling pathway. This method was able to successfully reproduce various experimental measurements for the rate constant of these reactions. However, it was not able to reproduce the faster-than-expected rate of Mu + C3H8 at 300 K reported by Fleming et al. [Phys. Chem. Chem. Phys., 2015, 17, 19901 and Phys. Chem. Chem. Phys., 2020, 22, 6326]. Analysis of our results indicates that the kinetic isotope effect at this temperature is not significantly influenced by quantum tunnelling. We consider many possible factors for the discrepancy between theory and experiment but conclude that in each case, the instanton approximation is unlikely to be the cause of the error. This is in part based on the good agreement we find between the instanton predictions and new multiconfigurational time-dependent Hartree (MCTDH) calculations for Mu + CH4 using the same potential-energy surface. Further experiments will therefore be needed to resolve this issue.
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Affiliation(s)
- Gabriel Laude
- Laboratory of Physical Chemistry, ETH Zürich, Switzerland.
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32
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Nandi A, Bowman JM, Houston P. A Machine Learning Approach for Rate Constants. II. Clustering, Training, and Predictions for the O(3P) + HCl → OH + Cl Reaction. J Phys Chem A 2020; 124:5746-5755. [DOI: 10.1021/acs.jpca.0c04348] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Apurba Nandi
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Joel M. Bowman
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Paul Houston
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
- Department of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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33
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Koner D, Bemish RJ, Meuwly M. Dynamics on Multiple Potential Energy Surfaces: Quantitative Studies of Elementary Processes Relevant to Hypersonics. J Phys Chem A 2020; 124:6255-6269. [DOI: 10.1021/acs.jpca.0c01870] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Debasish Koner
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, 4056 Basel, Switzerland
| | - Raymond J. Bemish
- Air Force Research Laboratory, Space Vehicles Directorate, Kirtland AFB, New Mexico 87117, United States
| | - Markus Meuwly
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, 4056 Basel, Switzerland
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34
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A General User-Friendly Tool for Kinetic Calculations of Multi-Step Reactions within the Virtual Multifrequency Spectrometer Project. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10051872] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We discuss the implementation of a computer program for accurate calculation of the kinetics of chemical reactions integrated in the user-friendly, multi-purpose Virtual Multifrequency Spectrometer tool. The program is based on the ab initio modeling of the involved molecular species, the adoption of transition-state theory for each elementary step of the reaction, and the use of a master-equation approach accounting for the complete reaction scheme. Some features of the software are illustrated through examples including the interconversion reaction of hydroxyacetone and 2-hydroxypropanal and the production of HCN and HNC from vinyl cyanide.
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35
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Houston PL, Nandi A, Bowman JM. A Machine Learning Approach for Prediction of Rate Constants. J Phys Chem Lett 2019; 10:5250-5258. [PMID: 31423788 DOI: 10.1021/acs.jpclett.9b01810] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report a machine learning approach to train and predict bimolecular thermal rate constants over a large temperature range. The approach uses Gaussian process (GP) regression to evaluate the difference between accurate quantum results and Eckart-corrected conventional transition state theory, mostly for collinear reactions. Training is done on a database of rate constants for 13 reaction/potential surface combinations, and testing is performed on a set of 39 reaction/potential surface combinations. Averaged over all test reactions, the GP method is within 80% of the accurate answer, whereas transition state theory (TST) is only within 330% and Eckart-corrected TST (ECK) is within 110%. In the tunneling region, GP is generally (with a few exceptions) more accurate and sometimes much more accurate. In the high-temperature recrossing region, GP is significantly more accurate than either TST or ECK, neither of which addresses the possibility of recrossing. The GP predictions for the 3D reactions O(3P) + H2, OH + H2, O(3P) + CH4, and H + CH4, for which accurate quantum results are available, provide further encouragement to the machine learning approach.
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Affiliation(s)
- Paul L Houston
- Department of Chemistry & Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Apurba Nandi
- Department of Chemistry and Cherry L. Emerson Center for Scientic Computation, Emory University, Atlanta, Georgia 30322, United States
| | - Joel M Bowman
- Department of Chemistry and Cherry L. Emerson Center for Scientic Computation, Emory University, Atlanta, Georgia 30322, United States
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36
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Wang H, Fang J, Yang H, Song J, Li Y. Ring-polymer molecular dynamical benchmarks for X + H2 insertion reactions. Chem Phys Lett 2019. [DOI: 10.1016/j.cplett.2019.06.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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37
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De Fazio D, Aquilanti V, Cavalli S. Quantum Dynamics and Kinetics of the F + H 2 and F + D 2 Reactions at Low and Ultra-Low Temperatures. Front Chem 2019; 7:328. [PMID: 31157204 PMCID: PMC6527900 DOI: 10.3389/fchem.2019.00328] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 04/24/2019] [Indexed: 11/29/2022] Open
Abstract
Integral cross sections and rate constants for the prototypical chemical reactions of the fluorine atom with molecular hydrogen and deuterium have been calculated over a wide interval of collision energy and temperature ranging from the sub-thermal (50 K) down to the ultra-cold regimes (0.5 mK). Rigorous close coupling time-independent quantum reactive scattering calculations have been carried out on two potential energy surfaces, differing only at long-range in the reactants' channel. The results show that tunnel, resonance and virtual state effects enhance under-barrier reactivity giving rise to pronounced deviations from the Arrhenius law as temperature is lowered. Within the ultra-cold domain (below 1 mK), the reactivity is governed by virtual state effects and by tunneling through the reaction barrier; in the cold regime (1 mK–1 K), the shape resonances in the entrance channel of the potential energy surface make the quantum tunneling contribution larger so enhancing cross sections and rate constants by about one order of magnitude; at higher temperatures (above 10 K), the tunneling pathway enhanced by the constructive interference between two Feshbach resonances trapped in the reaction exit channel competes with the thermally activated mechanism, as the energy gets closer to the reaction barrier height. The results show that at low temperatures cross sections and rate constants are extremely sensitive to small changes in the long-range intermolecular interaction in the entrance channel of the potential energy surface, as well as to isotopic substitution.
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Affiliation(s)
- Dario De Fazio
- Istituto di Struttura della Materia, Consiglio Nazionale Delle Ricerche (CNR), Rome, Italy
| | - Vincenzo Aquilanti
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
| | - Simonetta Cavalli
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, Perugia, Italy
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38
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Li J. Ring-polymer molecular dynamics studies of thermal rate coefficients for reaction F + H2O → HF + OH. CHINESE J CHEM PHYS 2019. [DOI: 10.1063/1674-0068/cjcp1808186] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Jun Li
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China
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39
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Zhao H, Umer U, Hu X, Xie D, Sun Z. An interaction-asymptotic region decomposition method for general state-to-state reactive scatterings. J Chem Phys 2019; 150:134105. [DOI: 10.1063/1.5085651] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Hailin Zhao
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People’s Republic of China and Center for Advanced Chemical Physics and 2011 Frontier Centre for Quantum Science and Technology, University of Science and Technology of China, 96 Jinzhai Road, Hefei 230026, China
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Umair Umer
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People’s Republic of China and Center for Advanced Chemical Physics and 2011 Frontier Centre for Quantum Science and Technology, University of Science and Technology of China, 96 Jinzhai Road, Hefei 230026, China
| | - Xixi Hu
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Daiqian Xie
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Zhigang Sun
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People’s Republic of China and Center for Advanced Chemical Physics and 2011 Frontier Centre for Quantum Science and Technology, University of Science and Technology of China, 96 Jinzhai Road, Hefei 230026, China
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40
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Wu Y, Cao J, Ma H, Zhang C, Bian W, Nunez-Reyes D, Hickson KM. Conical intersection-regulated intermediates in bimolecular reactions: Insights from C( 1D) + HD dynamics. SCIENCE ADVANCES 2019; 5:eaaw0446. [PMID: 31032418 PMCID: PMC6486230 DOI: 10.1126/sciadv.aaw0446] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 03/11/2019] [Indexed: 06/09/2023]
Abstract
The importance of conical intersections (CIs) in electronically nonadiabatic processes is well known, but their influence on adiabatic dynamics has been underestimated. Here, through combined experimental and theoretical studies, we show that CIs induce a barrier and regulate conversion from a precursor metastable intermediate (CI-R) to a deep well one. This results in bond-selective activation, influencing the adiabatic dynamics markedly in the C(1D) + HD reaction. Theory is validated by experiment; quantum dynamics calculations on highly accurate ab initio potential energy surfaces yield rate coefficients and product branching ratios in excellent agreement with the experiment. Quasi-classical trajectory calculations reveal that the CI-R intermediate leads to unusual reaction mechanisms (designated as C─H activation complex conversion and cyclic complex), which are responsible for large branching ratios. We also reveal that CI-R intermediates exist in other reactive systems, and the dynamical effects uncovered here may have general significance.
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Affiliation(s)
- Yanan Wu
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jianwei Cao
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Haitao Ma
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Chunfang Zhang
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- College of Chemistry and Environmental Science, Hebei University, Baoding 071002, China
| | - Wensheng Bian
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dianailys Nunez-Reyes
- Université de Bordeaux, Institut des Sciences Moléculaires, F-33400 Talence, France
- CNRS, Institut des Sciences Moléculaires, UMR 5255, F-33400 Talence, France
| | - Kevin M. Hickson
- Université de Bordeaux, Institut des Sciences Moléculaires, F-33400 Talence, France
- CNRS, Institut des Sciences Moléculaires, UMR 5255, F-33400 Talence, France
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41
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Welsch R. Kinetic isotope effects in the water forming reaction H2/D2 + OH from rigorous close-coupling quantum dynamics simulations. Phys Chem Chem Phys 2019; 21:17054-17062. [DOI: 10.1039/c9cp02323b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Rigorous quantum dynamics simulations of thermal rate constants and kinetic isotope effects for the water-forming H2/D2 + OH reaction are presented, which show increased tunneling below 300 K and can serve as benchmarks for approximate methods.
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Affiliation(s)
- Ralph Welsch
- Center for Free-Electron Laser Science
- DESY
- 22607 Hamburg
- Germany
- The Hamburg Centre for Ultrafast Imaging
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42
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Han S, Xie D, Guo H. Modified Gaussian Wave Packet Method for Calculating Initial State Wave Functions in Photodissociation. J Chem Theory Comput 2018; 14:5527-5534. [PMID: 30234984 DOI: 10.1021/acs.jctc.8b00771] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A modified Gaussian wave packet relaxation method is proposed to calculate the ground state wave function using an expansion of frozen Gaussian wave packets. This new procedure consists of two steps. In the first step, a multidimensional Gaussian product placed at the ground state equilibrium geometry is propagated in imaginary time. The relaxation optimizes the widths of the one-dimensional Gaussians. In the second step, additional Gaussian wave packets with the same widths are placed near the equilibrium geometry, and the corresponding expansion coefficients are optimized using the same relaxation method. This new algorithm is tested in photodissociation of NOCl and NH3, and the results show good agreement with the exact results in the energy, wave function, and absorption spectrum. In particular, the highly structured absorption spectrum of NH3 is reproduced, underscoring the accuracy of both the initial wave packet and the excited state propagation.
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Affiliation(s)
- Shanyu Han
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210093 , China.,Department of Chemistry and Chemical Biology , University of New Mexico , Albuquerque , New Mexico 87131 , United States
| | - Daiqian Xie
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210093 , China
| | - Hua Guo
- Department of Chemistry and Chemical Biology , University of New Mexico , Albuquerque , New Mexico 87131 , United States
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43
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Zhao H, Hu X, Xie D, Sun Z. Quantum wavepacket method for state-to-state reactive cross sections in hyperspherical coordinates. J Chem Phys 2018; 149:174103. [DOI: 10.1063/1.5042066] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Hailin Zhao
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People’s Republic of China and Center for Advanced Chemical Physics and 2011 Frontier Centre for Quantum Science and Technology, University of Science and Technology of China, 96 Jinzhai Road, Hefei 230026, China
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Xixi Hu
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Daiqian Xie
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Zhigang Sun
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People’s Republic of China and Center for Advanced Chemical Physics and 2011 Frontier Centre for Quantum Science and Technology, University of Science and Technology of China, 96 Jinzhai Road, Hefei 230026, China
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44
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Welsch R. Low‐Temperature Thermal Rate Constants for the Water Formation Reaction H
2
+OH from Rigorous Quantum Dynamics Calculations. Angew Chem Int Ed Engl 2018; 57:13150-13153. [DOI: 10.1002/anie.201807666] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Ralph Welsch
- Center for Free-Electron Laser Science, DESY Notkestraße 85 22607 Hamburg Germany
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45
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Welsch R. Low‐Temperature Thermal Rate Constants for the Water Formation Reaction H
2
+OH from Rigorous Quantum Dynamics Calculations. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201807666] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ralph Welsch
- Center for Free-Electron Laser Science, DESY Notkestraße 85 22607 Hamburg Germany
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46
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Tennyson J, McKemmish LK, Rivlin T. Low-temperature chemistry using the R-matrix method. Faraday Discuss 2018; 195:31-48. [PMID: 27711838 DOI: 10.1039/c6fd00110f] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Techniques for producing cold and ultracold molecules are enabling the study of chemical reactions and scattering at the quantum scattering limit, with only a few partial waves contributing to the incident channel, leading to the observation and even full control of state-to-state collisions in this regime. A new R-matrix formalism is presented for tackling problems involving low- and ultra-low energy collisions. This general formalism is particularly appropriate for slow collisions occurring on potential energy surfaces with deep wells. The many resonance states make such systems hard to treat theoretically but offer the best prospects for novel physics: resonances are already being widely used to control diatomic systems and should provide the route to steering ultracold reactions. Our R-matrix-based formalism builds on the progress made in variational calculations of molecular spectra by using these methods to provide wavefunctions for the whole system at short internuclear distances, (a regime known as the inner region). These wavefunctions are used to construct collision energy-dependent R-matrices which can then be propagated to give cross sections at each collision energy. The method is formulated for ultracold collision systems with differing numbers of atoms.
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Affiliation(s)
- Jonathan Tennyson
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK.
| | - Laura K McKemmish
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK.
| | - Tom Rivlin
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK.
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47
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Xie C, Guo H. Active vs. spectator modes in nonadiabatic photodissociation dynamics of the hydroxymethyl radical via the 2 2A(3s) Rydberg state. J Chem Phys 2018; 148:044305. [PMID: 29390808 DOI: 10.1063/1.5017737] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The choice of the active degrees of freedom (DOFs) is a pivotal issue in a reduced-dimensional model of quantum dynamics when a full-dimensional one is not feasible. Here, several five-dimensional (5D) models are used to investigate the nonadiabatic photodissociation dynamics of the hydroxymethyl (CH2OH) radical, which possesses nine internal DOFs, in its lowest absorption band. A normal-mode based scheme is used to identify the active and spectator modes, and its predictions are confirmed by 5D quantum dynamical calculations. Our results underscore the important role of the CO stretching mode in the photodissociation dynamics of CH2OH, originating from the photo-induced promotion of an electron from the half-occupied π*CO antibonding orbital to a carbon Rydberg orbital.
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Affiliation(s)
- Changjian Xie
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Hua Guo
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA
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48
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Jambrina PG, Menéndez M, Aoiz FJ. Angular momentum-scattering angle quantum correlation: a generalized deflection function. Chem Sci 2018; 9:4837-4850. [PMID: 29910936 PMCID: PMC5982215 DOI: 10.1039/c7sc05489k] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 04/25/2018] [Indexed: 11/23/2022] Open
Abstract
A natural generalization of the classical deflection function, the functional dependence of the deflection angle on the angular momentum (or the impact parameter), is the joint probability density function of these two quantities, revealing the correlation between them. It provides, at a glance, detailed information about the reaction mechanisms and how changes in the impact parameter affect the product angular distribution. It is also useful to predict the presence of quantum phenomena such as interference. However, the classical angular momentum-scattering angle correlation function has a limited use whenever quantum effects become important. Rigorously speaking, there is not a quantum equivalent of the classical joint distribution, as the differential cross section depends on the coherences between the different values of J caused by the cross terms in the expansion of partial waves. In this article, we present a simple method to calculate a quantum analog of this correlation, a generalized deflection function that can shed light onto the reaction mechanism using just quantum mechanical results. Our results show that there is a very good agreement between the quantum and classical correlation functions as long as quantum effects are not all relevant. When this is not the case, it will also be shown that the quantum correlation function is most useful to observe the extent of quantum effects such as interference among different reaction mechanisms.
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Affiliation(s)
- P G Jambrina
- Departamento de Química Física Aplicada , Universidad Autonoma de Madrid , 28049 , Madrid , Spain .
| | - M Menéndez
- Departamento de Química Física I , Facultad de Ciencias Químicas , Universidad Complutense de Madrid , 28040 Madrid , Spain .
| | - F J Aoiz
- Departamento de Química Física I , Facultad de Ciencias Químicas , Universidad Complutense de Madrid , 28040 Madrid , Spain .
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49
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Welsch R. Rigorous close-coupling quantum dynamics calculation of thermal rate constants for the water formation reaction of H2 + OH on a high-level PES. J Chem Phys 2018; 148:204304. [DOI: 10.1063/1.5033358] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Ralph Welsch
- Center for Free-Electron Laser Science, DESY, Notkestrasse 85, 22607 Hamburg, Germany
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50
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Zuo JX, Hu XX, Xie DQ. Quantum Dynamics of Oxyhydrogen Complex-Forming Reactions for the HO2 and HO3 Systems. CHINESE J CHEM PHYS 2018. [DOI: 10.1063/1674-0068/31/cjcp1804060] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Jun-xiang Zuo
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Xi-xi Hu
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Dai-qian Xie
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
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