The ViRAPID team has developed the NAFFS (nonadiabatic forward flux sampling) methodology for sampling rare events in electronically excited states! Our approach extends the computationally available time scale in photoreactions to way beyond what is currently feasible.

The NAFFS method extends and combines the enhanced sampling algorithm forward flux sampling and the SHARC surface hopping approach to enable rare event sampling of chemical reaction pathways where more than one potential energy surface is relevant.

We show in our paper using photochemically relevant analytical models, that we can achieve significant speed-ups, depending on the energy barrier, of multiple orders of magnitude compared to traditional methods.