A Size-Consistent Multi-State Mapping Approach to Surface Hopping

TL;DR

This paper introduces a size-consistent multi-state extension of the MASH surface hopping method, enabling accurate simulation of systems with multiple electronic states in nonadiabatic dynamics.

Contribution

It presents a novel multi-state generalization of MASH that is size consistent and reduces to the original in two-state cases, improving nonadiabatic simulation capabilities.

Findings

Accurately reproduces benchmark results for model systems.

Effective for simulating photochemical relaxation processes.

Maintains size consistency across multiple states.

Abstract

We develop a multi-state generalisation of the recently proposed mapping approach to surface hopping (MASH) for the simulation of electronically nonadiabatic dynamics. This new approach extends the original MASH method to be able to treat systems with more than two electronic states. It differs from previous approaches in that it is size consistent and rigorously recovers the original two-state MASH in appropriate limits. We demonstrate the accuracy of the method by application to a series of model systems for which exact benchmark results are available, and find that the method is well suited to the simulation of photochemical relaxation processes.