Evaluation of the importance of spin-orbit couplings in the nonadiabatic quantum dynamics with quantum fidelity and with its efficient "on-the-fly" ab initio semiclassical approximation

Abstract

We propose to measure the importance of spin-orbit couplings (SOCs) in the nonadiabatic molecular quantum dynamics rigorously with quantum fidelity. To make the criterion practical, quantum fidelity is estimated efficiently with the multiple-surface dephasing representation (MSDR). The MSDR is a semiclassical method that includes nuclear quantum effects through interference of mixed quantum-classical trajectories without the need for the Hessian of potential energy surfaces. Two variants of the MSDR are studied, in which the nuclei are propagated either with the fewest-switches surface hopping or with the locally mean field dynamics. The fidelity criterion and MSDR are first tested on one-dimensional model systems amenable to numerically exact quantum dynamics. Then, the MSDR is combined with "on-the-fly" computed electronic structure to measure the importance of SOCs and nonadiabatic couplings (NACs) in the photoisomerization dynamics of CH2NH2+ considering 20 electronic states and in the collision of F + H2 considering six electronic states.

arXiv comment9 pages, 3 figures, submitted to J. Chem. Phys

References in corpus (12)

• Dynamics of Loschmidt echoes and fidelity decay
• Mixing Quantum and Classical Mechanics
• Impediments to mixing classical and quantum dynamics
• Semiclassical evaluation of quantum fidelity
• Dephasing representation: Employing the shadowing theorem to calculate quantum correlation functions
• Dephasing representation of quantum fidelity for general pure and mixed states
• Evaluation of the nondiabaticity of quantum molecular dynamics with the dephasing representation of quantum fidelity
• Measuring nonadiabaticity of molecular quantum dynamics with quantum fidelity and with its efficient semiclassical approximation
• Beating the efficiency of both quantum and classical simulations with semiclassics
• Universal Response of Quantum Systems with Chaotic Dynamics
• Semiclassical approach to fidelity amplitude
• Optimizing adiabaticity in quantum mechanics

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• Improving the accuracy and efficiency of time-resolved electronic spectra calculations: Cellular dephasing representation with a prefactor
• High-order geometric integrators for representation-free Ehrenfest dynamics