A new implementation of <i>ab initio</i> ehrenfest dynamics using electronic configuration basis: Exact formulation with molecular orbital connection and effective propagation scheme with locally quasi‐diabatic representation

Kunisada, Tomotaka; Ushiyama, Hiroshi; Yamashita, Koichi

doi:10.1002/qua.25156

Cited by 3 publications

(3 citation statements)

References 41 publications

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“…Both CH2NH2 + and azomethane (Scheme 1) were often taken as typical examples to test the direct nonadiabatic dynamics approaches. 30,106,[108][109][110][111][112][113][114][115][116][117][118][119][120][121] Therefore, we also examined their excited state dynamics by using the on-the-fly SQC/MM dynamics. In addition, the FSSH dynamics were also performed.…”

Section: Computational Detailsmentioning

confidence: 99%

On-the-Fly Symmetrical Quasi-Classical Dynamics with Meyer–Miller Mapping Hamiltonian for the Treatment of Nonadiabatic Dynamics at Conical Intersections

Xie

Peng

et al. 2021

J. Chem. Theory Comput.

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The on-the-fly version of the symmetrical quasi-classical dynamics method based on the Meyer-Miller mapping Hamiltonian (SQC/MM) is implemented to study the nonadiabatic dynamics at conical intersections of polyatomic systems. The current on-the-fly implementation of the SQC/MM method is based on the adiabatic representation and the dressed momentum. To include the zero-point energy (ZPE) correction of the electronic mapping variables, we employ both the γadjusted and γ-fixed approaches. Nonadiabatic dynamics of the methaniminium cation (CH2NH2 + ) and azomethane are simulated using the on-the-fly SQC/MM method. For CH2NH2 + , both two ZPE correction approaches give reasonable and consistent results. However, for azomethane, the γ-adjusted version of the SQC/MM dynamics behaves much better than the γ-fixed version. The further analysis indicates that it is always recommended to use the γ-adjusted SQC/MM dynamics in the on-the-fly simulation of photoinduced dynamics of polyatomic systems, particularly when the excited-state is well separated from the ground state in the Franck-Condon region. This work indicates that the on-the-fly SQC/MM method is a powerful simulation protocol to deal with the nonadiabatic dynamics of realistic polyatomic systems.

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Section: Computational Detailsmentioning

confidence: 99%

On-the-Fly Symmetrical Quasi-Classical Dynamics with Meyer–Miller Mapping Hamiltonian for the Treatment of Nonadiabatic Dynamics at Conical Intersections

Xie

Peng

et al. 2021

J. Chem. Theory Comput.

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show abstract

“…Both CH2NH2 + and azomethane (Scheme 1) were often taken as typical examples to test the direct nonadiabatic dynamics approaches. 30,[106][107][108][109][110][111][112][113][114][115][116][117][118][119][120] Therefore, we also examined their excited state dynamics by using the on-the-fly SQC/MM dynamics. In addition, the FSSH dynamics were also performed.…”

Section: Computational Detailsmentioning

confidence: 99%

On-the-fly Symmetrical Quasi-classical Dynamics with Meyer-Miller Mapping Hamiltonian for the Treatment of Nonadiabatic Dynamics at Conical Intersections

Da¹,

Xie²,

Peng³

et al. 2020

Preprint

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The ‘on-the-fly’ version of the symmetrical quasi-classical dynamics method based on the Meyer-Miller mapping Hamiltonian (SQC/MM) is implemented to study the nonadiabatic dynamics at conical intersections of polyatomic systems. The current ‘on-the-fly’ implementation of the SQC/MM method is based on the adiabatic representation and the dressed momentum. To include the zero-point energy (ZPE) correction of the electronic mapping variables, we employed both the γ-adjusted and γ-fixed approaches. Nonadiabatic dynamics of the methaniminium cation (CH2NH2+) and azomethane are simulated using the on-the-fly SQC/MM method. For CH2NH2+, both two ZPE correction approaches give reasonable and consistent results. However, for azomethane, the γ-adjusted version of the SQC/MM dynamics behaves much better than the γ-fixed version. The further analysis indicates that it is always recommended to use the γ-adjusted SQC/MM dynamics in the on-the-fly simulation of photoinduced dynamics of polyatomic systems, particularly when the excited-state is well separated from the ground state in the Frank-Condon region. This work indicates that the on-the-fly SQC/MM method is a powerful simulation protocol to deal with the nonadiabatic dynamics of realistic polyatomic systems.

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“…One of the most successful first-principles mixed quantum–classical algorithms is the mean-field Ehrenfest approach, − in which the nuclei are subject to a classical force determined by the instantaneous average density of the electrons. However, as a mean-field approach, it cannot properly describe correlated electron–nuclear processes.…”

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confidence: 99%

Improved Ehrenfest Approach to Model Correlated Electron–Nuclear Dynamics

Baskov

White

2019

J. Phys. Chem. Lett.

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Mixed quantum-classical mechanics descriptions are critical to modeling coupled electron-nuclear dynamics, i.e. non-adiabatic molecular dynamics, relevant to photochemical and photophysical processes. We argue that, for polyatomic molecules, such mixed dynamics can not be efficiently described in terms of a matrix gauge potential and develop the concept of a "length gauge" effective Hamiltonian, which helps clarifying certain aspects for the popular non-adiabatic computational approaches. In particular, within such an effective Hamiltonian formalism one readily derives the momentum rescaling boundary condition, used in the surface hopping algorithms. Furthermore, using the new formalism, we introduce a coupled Gaussian wavepacket parameterization of the nuclear wavefunction, which generalizes the Ehrenfest approach to account for electron-nuclei correlations. We test this new approach, Ehrenfest-Plus, on the standard set of model problems that probe electron-nuclear correlation in non-adiabatic transitions. The high accuracy of our approach, combined with mixed-quantum classical efficiency, opens a path for improved simulation of nonadiabatic molecular dynamics in realistic molecular systems. arXiv:1808.05263v2 [physics.chem-ph]

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A new implementation of ab initio ehrenfest dynamics using electronic configuration basis: Exact formulation with molecular orbital connection and effective propagation scheme with locally quasi‐diabatic representation

Cited by 3 publications

References 41 publications

On-the-Fly Symmetrical Quasi-Classical Dynamics with Meyer–Miller Mapping Hamiltonian for the Treatment of Nonadiabatic Dynamics at Conical Intersections

On-the-Fly Symmetrical Quasi-Classical Dynamics with Meyer–Miller Mapping Hamiltonian for the Treatment of Nonadiabatic Dynamics at Conical Intersections

On-the-fly Symmetrical Quasi-classical Dynamics with Meyer-Miller Mapping Hamiltonian for the Treatment of Nonadiabatic Dynamics at Conical Intersections

Improved Ehrenfest Approach to Model Correlated Electron–Nuclear Dynamics

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