• Chinese Journal of Chemical Physics
  • Vol. 33, Issue 5, 05000603 (2020)
Xiao Bing-yang, Xu Jia-bo, and Wang Lin-jun*

Abstract

Inspired by the branching corrected surface hopping (BCSH) method [J. Xu and L. Wang, J. Chem. Phys. 150, 164101 (2019)], we present two new decoherence time formulas for trajectory surface hopping. Both the proposed linear and exponential formulas characterize the decoherence time as functions of the energy difference between adiabatic states and correctly capture the decoherence effect due to wave packet reflection as predicted by BCSH. The relevant parameters are trained in a series of 200 diverse models with different initial nuclear momenta, and the exact quantum solutions are utilized as references. As demonstrated in the three standard Tully models, the two new approaches exhibit significantly higher reliability than the widely used counterpart algorithm while holding the appealing efficiency, thus promising for nonadiabatic dynamics simulations of general systems.

Ⅰ INTRODUCTION

In chemistry, physics, biology, and material sciences, there exist many important dynamical processes, e.g., proton transfer [1, 2], photoisomerization [3-5], charge transport [6-8], nonradiative relaxation [9], energy transfer [10], exciton dissociation [11], and singlet fission [12, 13], which all belong to the category of nonadiabatic dynamics. In these circumstances, the traditional Born-Oppenheimer approximation breaks down and the motion of electronic and nuclear degrees of freedom becomes strongly coupled. In the past few decades, mixed quantum-classical dynamics has become a popular approach to simulate nonadiabatic dynamics [14]. Especially, Tully's fewest switches surface hopping (FSSH) algorithm combined with ab initio electronic structure calculations has achieved great success in different research fields [15]. In the standard FSSH and its variants, the electronic wavefunction is propagated quantum mechanically through solving the time-dependent Schrödinger equation (TDSE), the nuclei evolve classically on an active potential energy surface (PES), and surface hops occur stochastically on the basis of hopping probabilities [15-18]. Besides its advantage in formulation and implementation, trajectory surface hopping has generally shown a good balance between efficiency and reliability [19, 20].

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Bing-yang Xiao, Jia-bo Xu, Lin-jun Wang. New Energy-Based Decoherence Correction Approaches for Trajectory Surface Hopping[J]. Chinese Journal of Chemical Physics, 2020, 33(5): 603
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Received: Jun. 16, 2020
Accepted: Jul. 18, 2020
Published Online: Apr. 21, 2021
The Author Email: Wang Lin-jun (ljwang@zju.edu.cn)