Coupled Wavepackets for Non-Adiabatic Molecular Dynamics: A Generalization of Gaussian Wavepacket Dynamics to Multiple Potential Energy Surfaces

TL;DR

This paper introduces a new semiclassical method called coupled wavepackets, extending Gaussian wavepacket dynamics to multiple potential energy surfaces, efficiently capturing interference and decoherence in non-adiabatic molecular dynamics.

Contribution

It generalizes Gaussian wavepacket dynamics to include multiple potential energy surfaces, improving accuracy while maintaining computational efficiency.

Findings

Method accounts for interference and decoherence effects.

Systematic improvement of accuracy demonstrated.

Comparable efficiency to Ehrenfest and Surface Hopping methods.

Abstract

Accurate simulation of the non-adiabatic dynamics of molecules in excited electronic states is key to understanding molecular photo-physical processes. Here we present a novel method, based on a semiclassical approximation, that is as efficient as the commonly used mean field Ehrenfest or ad hoc Surface Hopping methods and properly accounts for interference and decoherence effects. This novel method is an extension of Hellers Thawed Gaussian wavepacket dynamics that includes coupling between potential energy surfaces. The accuracy of the method can be systematically improved.