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arXiv · 1501.06816

Why do mixed quantum-classical methods describe short-time dynamics through conical intersections so well? Analysis of geometric phase effects

Rami Gherib·Ilya G. Ryabinkin·Artur F. Izmaylov
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Abstract

Adequate simulation of non-adiabatic dynamics through conical intersection requires account for a non-trivial geometric phase (GP) emerging in electronic and nuclear wave-functions in the adiabatic representation. Popular mixed quantum-classical (MQC) methods, surface hopping and Ehrenfest, do not carry a nuclear wave-function to be able to incorporate the GP into nuclear dynamics. Surprisingly, the MQC methods reproduce ultra-fast interstate crossing dynamics generated with the exact quantum propagation so well as if they contained information about the GP. Using two-dimensional linear vibronic coupling models we unravel how the MQC methods can effectively mimic the most significant dynamical GP effects: 1) compensation for repulsive diagonal second order non-adiabatic couplings and 2) transfer enhancement for a fully cylindrically symmetric component of a nuclear distribution.

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Rami Gherib, Ilya G. Ryabinkin, Artur F. Izmaylov. 2015-03-03. Why do mixed quantum-classical methods describe short-time dynamics through conical intersections so well? Analysis of geometric phase effects. https://doi.org/10.1021/acs.jctc.5b00072

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