Trajectory surface hopping study of the photodissociation dynamics of methyl radical from the 3 s and 3 p z Rydberg states

Highlights: • Aimed at filling the gap in the theoretical studies of the CH₃'s photo-dissociation. • Our results look promising reproducing the same trend as state of the art experiments. • The method used allows the interpretation of the internal mechanisms of the process. The photodissociation dynamics of methyl radical from selected vibrational levels of the $3s$ and $3p_z$ Rydberg states has been studied using the trajectory surface hopping method on one-dimensional potential energy curves along the carbon-hydrogen dissociative coordinate and the non-adiabatic couplings between them, calculated by ab initio methods. Lifetimes and product distributions have been obtained for all the studied vibrational levels and compared with previous theoretical and experimental works. The theoretical lifetimes tend to decrease as vibrational excitation increases in accordance with experimental results. The agreement, however, is only qualitative considering the reduced dimensionality of the model.