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Shu Y, Zhang L, Wu D, Chen X, Sun S, Truhlar DG. New Gradient Correction Scheme for Electronically Nonadiabatic Dynamics Involving Multiple Spin States. J Chem Theory Comput 2023; 19:2419-2429. [PMID: 37079755 DOI: 10.1021/acs.jctc.2c01173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
It has been recommended that the best representation to use for trajectory surface hopping (TSH) calculations is the fully adiabatic basis in which the Hamiltonian is diagonal. Simulations of intersystem crossing processes with conventional TSH methods require an explicit computation of nonadiabatic coupling vectors (NACs) in the molecular-Coulomb-Hamiltonian (MCH) basis, also called the spin-orbit-free basis, in order to compute the gradient in the fully adiabatic basis (also called the diagonal representation). This explicit requirement destroys some of the advantages of the overlap-based algorithms and curvature-driven algorithms that can be used for the most efficient TSH calculations. Therefore, although these algorithms allow one to perform NAC-free simulations for internal conversion processes, one still requires NACs for intersystem crossing. Here, we show that how the NAC requirement is circumvented by a new computation scheme called the time-derivative-matrix scheme.
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Affiliation(s)
- Yinan Shu
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
| | - Linyao Zhang
- School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, P. R. China
| | - Dihua Wu
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
| | - Xiye Chen
- School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, P. R. China
| | - Shaozeng Sun
- School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, P. R. China
| | - Donald G Truhlar
- Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
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Muthiah B, Kasai T, Lin KC. Probing BrCl from photodissociation of CH 2BrCl and CHBr 2Cl at 248 nm using cavity ring-down spectroscopy. Phys Chem Chem Phys 2021; 23:6098-6106. [PMID: 33683243 DOI: 10.1039/d0cp06350a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photodissociation of di- and tri-halogenated methanes including CH2BrCl and CHBr2Cl at 248 nm was investigated using cavity ringdown absorption spectroscopy (CRDS). The spectra of the BrCl(v'' = 2, 3) and Br2(v'' = 1, 2) fragments were probed over the wavelength range of 594.5-596 nm in the B3Π+0u ← X1Σ+g and B3Π (0+) ← X1Σ+ transitions, respectively. Their corresponding spectra were simulated for assignment of rotational lines at a given vibrational level. The quantum yields for Br2 eliminated from CHBr2Cl and BrCl from CH2BrCl were determined to be 0.048 ± 0.018 and 0.037 ± 0.014, respectively. The photodissociation of CHBr2Cl yielded only the Br2 fragment, but not the BrCl fragment in the experiments. An ab initio theoretical method based on the CCSD(T)//B3LYP/6-311g(d,p) level was employed to evaluate the potential energy surface for the dissociation pathways to produce Br2 and BrCl from CHBr2Cl, which encountered a transition state barrier of 445 and 484 kJ mol-1, respectively. The corresponding RRKM rate constants were calculated to show that the branching ratio of (Br2/BrCl) is ∼20. The BrCl spectrum is expected to be obscured by the much larger Br2 spectrum, explaining why BrCl fragments cannot be detected in the photolysis of CHBr2Cl.
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Affiliation(s)
- Balaganesh Muthiah
- Department of Chemistry, National Taiwan Univeristy, Taipei 106, Taiwan.
| | - Toshio Kasai
- Department of Chemistry, National Taiwan Univeristy, Taipei 106, Taiwan. and Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - King-Chuen Lin
- Department of Chemistry, National Taiwan Univeristy, Taipei 106, Taiwan. and Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan
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Shu Y, Zhang L, Mai S, Sun S, González L, Truhlar DG. Implementation of Coherent Switching with Decay of Mixing into the SHARC Program. J Chem Theory Comput 2020; 16:3464-3475. [DOI: 10.1021/acs.jctc.0c00112] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Yinan Shu
- Department of Chemistry and Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
| | - Linyao Zhang
- Department of Chemistry and Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
- School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, People’s Republic of China
| | - Sebastian Mai
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 17, 1090, Vienna, Austria
| | - Shaozeng Sun
- School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, People’s Republic of China
| | - Leticia González
- Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Str. 17, 1090, Vienna, Austria
| | - Donald G. Truhlar
- Department of Chemistry and Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States
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Mandal A, Hunt KLC. Variance of the energy of a quantum system in a time-dependent perturbation: Determination by nonadiabatic transition probabilities. J Chem Phys 2020; 152:104110. [DOI: 10.1063/1.5140009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Anirban Mandal
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - Katharine L. C. Hunt
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
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Godara S, Paranjothy M. Competing Molecular and Radical Pathways in the Dissociation of Halons via Direct Chemical Dynamics Simulations. J Phys Chem A 2019; 123:8527-8535. [PMID: 31539256 DOI: 10.1021/acs.jpca.9b06564] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A great deal of attention has been given to the decomposition chemistry of halons (halomethanes) due to their role in stratospheric ozone depletion. Knowledge of certain aspects of dissociation of halons such as the competition between radical and molecular pathways and their mechanistic details is limited. Halon molecules can isomerize to an iso form containing a halogen-halogen bond and such iso-halon forms have been identified as intermediates in condensed phase chemistry. Recently, a quantum chemistry study of role of iso-halons in the gas phase decomposition of halomethanes has been reported. In the present work, we have investigated the ground state dissociation chemistry of select halon molecules - CF2Cl2, CF2Br2, CHBr3, and CH2BrCl using electronic structure theory calculations and direct chemical dynamics simulations. Classical trajectories were generated on-the-fly using density functional PBE0/6-31G* level of theory at a fixed total energy. Simulation results showed that molecular products, in general, were dominant for all the four molecules at the chosen energy. A variety of mechanisms such as direct dissociation via multicenter transition states, decomposition via isomerization, radical recombinations, and roaming pathways contributed to the formation of molecular products. Atomic level mechanisms are presented, and the role of iso-halons in the gas phase chemistry of halomethanes is clearly established.
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Affiliation(s)
- Sumitra Godara
- Department of Chemistry , Indian Institute of Technology Jodhpur , Jodhpur , 342037 Rajasthan , India
| | - Manikandan Paranjothy
- Department of Chemistry , Indian Institute of Technology Jodhpur , Jodhpur , 342037 Rajasthan , India
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Chicharro DV, Marggi Poullain S, González-Vázquez J, Bañares L. Slice imaging of the UV photodissociation of CH 2BrCl from the maximum of the first absorption band. J Chem Phys 2017; 147:013945. [PMID: 28688417 DOI: 10.1063/1.4984789] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The photodissociation dynamics of bromochloromethane (CH2BrCl) have been investigated at the maximum of the first absorption band, at the excitation wavelengths 203 and 210 nm, using the slice imaging technique in combination with a probe detection of bromine-atom fragments, Br(2P3/2) and Br*(2P1/2), via (2 + 1) resonance enhanced multiphoton ionization. Translational energy distributions and angular distributions reported for both Br(2P3/2) and Br*(2P1/2) fragments show two contributions for the Br(2P3/2) channel and a single contribution for the Br*(2P1/2) channel. High level ab initio calculations have been performed in order to elucidate the dissociation mechanisms taking place. The computed absorption spectrum and potential energy curves indicate the main contribution of the populated 4A″, 5A', and 6A' excited states leading to a C-Br cleavage. Consistently with the results, the single contribution for the Br*(2P1/2) channel has been attributed to direct dissociation through the 6A' state as well as an indirect dissociation of the 5A' state requiring a 5A' → 4A' reverse non-adiabatic crossing. Similarly, a faster contribution for the Br(2P3/2) channel characterized by a similar energy partitioning and anisotropy than those for the Br*(2P1/2) channel is assigned to a direct dissociation through the 5A' state, while the slower component appears to be due to the direct dissociation on the 4A″ state.
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Affiliation(s)
- D V Chicharro
- Departmento de Química Física I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - S Marggi Poullain
- Departmento de Química Física I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - J González-Vázquez
- Departamento de Química and Institute for Advanced Research in Chemistry, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - L Bañares
- Departmento de Química Física I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
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Hoyer CE, Parker K, Gagliardi L, Truhlar DG. The DQ and DQΦ electronic structure diabatization methods: Validation for general applications. J Chem Phys 2016; 144:194101. [DOI: 10.1063/1.4948728] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Chad E. Hoyer
- Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455-0431, USA
| | - Kelsey Parker
- Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455-0431, USA
| | - Laura Gagliardi
- Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455-0431, USA
| | - Donald G. Truhlar
- Department of Chemistry, Chemical Theory Center, and Minnesota Supercomputing Institute, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455-0431, USA
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Merrill WG, Crim FF, Case AS. Dynamics and yields for CHBrCl2photodissociation from 215–265 nm. Phys Chem Chem Phys 2016; 18:32999-33008. [PMID: 27886282 DOI: 10.1039/c6cp05061a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We characterize the energy partitioning and spin–orbit yields for CHBrCl2photodissociation. Resonance enhanced multiphoton ionization selectively detects the Br and Br* product channels. Time of flight mass spectrometry and velocity-map imaging permit measurement of relative quantum yields, as well as kinetic and internal energy distributions. We further interpret the energy partitioning through use of impulsive models.
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Affiliation(s)
- Wyatt G. Merrill
- Department of Chemistry
- University of Wisconsin – Madison
- Madison
- USA
| | - F. Fleming Crim
- Department of Chemistry
- University of Wisconsin – Madison
- Madison
- USA
| | - Amanda S. Case
- Department of Chemistry
- University of Wisconsin – Madison
- Madison
- USA
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Li SL, Truhlar DG, Schmidt MW, Gordon MS. Model space diabatization for quantum photochemistry. J Chem Phys 2015; 142:064106. [DOI: 10.1063/1.4907038] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Shaohong L. Li
- Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Donald G. Truhlar
- Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | | | - Mark S. Gordon
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA
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Hoyer CE, Xu X, Ma D, Gagliardi L, Truhlar DG. Diabatization based on the dipole and quadrupole: The DQ method. J Chem Phys 2014; 141:114104. [DOI: 10.1063/1.4894472] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Chad E. Hoyer
- Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455-0431, USA
| | - Xuefei Xu
- Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455-0431, USA
| | - Dongxia Ma
- Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455-0431, USA
| | - Laura Gagliardi
- Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455-0431, USA
| | - Donald G. Truhlar
- Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, 207 Pleasant St. SE, Minneapolis, Minnesota 55455-0431, USA
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Xu X, Yang KR, Truhlar DG. Diabatic Molecular Orbitals, Potential Energies, and Potential Energy Surface Couplings by the 4-fold Way for Photodissociation of Phenol. J Chem Theory Comput 2013; 9:3612-25. [DOI: 10.1021/ct400447f] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Xuefei Xu
- Department of Chemistry,
Chemical Theory Center, and
Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota
55455-0431, United States
| | - Ke R. Yang
- Department of Chemistry,
Chemical Theory Center, and
Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota
55455-0431, United States
| | - Donald G. Truhlar
- Department of Chemistry,
Chemical Theory Center, and
Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota
55455-0431, United States
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12
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Yang KR, Xu X, Truhlar DG. Direct diabatization of electronic states by the fourfold-way: Including dynamical correlation by multi-configuration quasidegenerate perturbation theory with complete active space self-consistent-field diabatic molecular orbitals. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2013.04.036] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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