Incorporating Berry Force Effects into the Fewest Switches Surface-Hopping Algorithm: Intersystem Crossing and the Case of Electronic Degeneracy

We present a preliminary surface-hopping approach formodeling intersystem crossing (ISC) dynamics between four electronicstates: one singlet and one (triply degenerate) triplet. In order toincorporate all Berry force effects, the algorithm requires that, whenmoving along an adiabatic surface associated with the triplet manifold,one must also keep track of a quasi-diabatic index (akin to amsquantum number) for each trajectory. For a simple model problem, wefind that a great deal of new physics can be captured by our algorithm,setting the stage for larger, more realistic (or perhaps even ab initio)simulations in the future.

Automated summary

The research presents a surface-hopping approach for modeling dynamics between multiple electronic states, focusing on Berry force effects and quasi-diabatic index application, capturing a significant amount of new physics.