Ab initio surface hopping simulation on dissociative recombination of H3O+

The dissociative recombination of H3O+ has been studied by the ab initio direct trajectory simulations at the state-averaged complete active space self-consistent field level to investigate tendency in the branching ratios of the dissociative products. Five electronic states of H3O including two Rydberg states have been taken into account in the simulations, and nonadiabatic transitions among adiabatic states were taken into account by the Tully’s fewest switches algorithm. It is verified that the highest energy products, OH + 2H, were generated in 87% of trajectories, while the most exothermic products, H2O + H, were generated in 10% of trajectories.