Quantum Quality with Classical Cost: Ab Initio Nonadiabatic Dynamics Simulations using the Mapping Approach to Surface Hopping

Nonadiabatic dynamics methods are an essential tool for investigating photochemical processes. In the context of employing first principles electronic structure techniques, such simulations can be carried out in a practical manner using semiclassical trajectory-based methods or wave packet approaches. It is commonly thought that wave packet approaches offer inherent advantages over their semiclassical counterparts in terms of accuracy, and that this trait simply comes at a higher computational cost. Here we demonstrate that the mapping approach to surface hopping (MASH), a recently introduced trajectory-based nonadiabatic dynamics method, can be applied in tandem with ab initio electronic structure much more cheaply than wave packet techniques, without any loss in accuracy.