A coupled-trajectory approach for decoherence, frustrated hops and internal consistency in surface hopping

TL;DR

This paper introduces a novel coupled-trajectory surface hopping method that improves the treatment of decoherence, frustrated hops, and internal consistency in nonadiabatic molecular dynamics simulations.

Contribution

It proposes a new surface hopping scheme based on coupled trajectories and energy sharing, addressing key issues in nonadiabatic dynamics.

Findings

Demonstrates improved electronic and vibrational property predictions

Shows robustness of the new scheme in photodynamics simulations

Reports encouraging results on fulvene and benzonitrile molecules

Abstract

We address the issues of decoherence, frustrated hops and internal consistency in surface hopping. We demonstrate that moving away from an independent-trajectory picture is the strategy which allows us to propose a robust surface hopping scheme overcoming all these issues at once. Based on the exact factorization and on the idea of coupled trajectories, we consider the swarm of trajectories, that mimics the nuclear dynamics in nonadiabatic processes, as a unique entity. In this way, imposing energy conservation of the swarm and allowing the trajectories to share energy when hops occur clearly indicates the route towards a new surface hopping scheme. Encouraging results are reported, in terms of electronic and vibrational time-dependent properties on the photodynamics of fulvene and 4-(dimethyloamino)benzonitrile, modeled with a full-dimensional linear vibronic coupling Hamiltonian.