Theoretical study of the photodissociation reaction of methanol

Abstract The photodissociation of methanol, which is an important radical source on interstellar ices, was studied using quantum chemistry calculations. Surface hopping simulations using the time-dependent density functional theory were performed, and the potential energy curves of the low-lying excited states were analyzed using the second-order multireference perturbation theory to reveal the reaction mechanism in the gas phase. We showed that the generation of CH 3 O would more frequently occur than that of CH 2 OH on the S 1 state in contrast to the ground state. We also discuss why the ratio of CH 3 O and CH 2 OH differs between the gas and solid phases.