The treatment of classically forbidden electronic transitions in semiclassical trajectory surface hopping calculations

Semiclassical methods were tested on a family of four weakly coupled three-atom systems called the YRH systems with features qualitatively similar to the BrH₂ system. Using the TFS algorithm, it was found, for the model systems studied, that hopping to the ground state is rare, but once the system is in the ground state, a large percentage of trajectories experience at least one frustrated hopping attempt. This observation indicates that the new YRH model systems provide a good test cases for studying the treatment of frustrated hops.