Spin-orbit ab initio investigation of the photodissociation of C2H5Br

The photodissociation of ethyl bromide (C2H5Br) has been investigated by spin-orbit (SO) ab initio calculations. The vertical excitation energies of some excited states for C2H5Br were calculated. The potential energy curves of C2H5Br along the C-Br dissociation coordinate were calculated by multistate second-order multiconfigurational perturbation theory in conjunction with spin-orbit (SO) interaction through complete active space state interaction (MS-CASPT2/CASSI-SO). The calculated results clearly assigned the experimentally observed photodissociation channels leading to C2H5 + Br (P-2(3/2)) and C2H5 + Br*(P-2(1/2)).