Calculation of the Raman spectrum of photodissociating H2S around 195 nm

Calculated Raman spectra of photodissociating H2S in its first absorption b and are presented, obtained by time dependent wave packet propagation on tw o coupled diabatic excited-state surfaces, a bound one (of B-1 symmetry in C-2 nu) and a repulsive one (A(2) symmetry). Both of these states are of A" symmetry in the C-s group and have a conical intersection in the Franck-Co ndon region. Predicted Raman spectra are presented for four excitation wave lengths in the range of 185-205 nm, and various features of the spectra are explored and compared with experimental data. The different behavior of [n 00] lines (those involving vibrational excitation in one H-S bond only, in the local mode picture) to that of other [n10] and [nm1] lines (involving o ne stretching quantum in one H-S bond and one bending quantum, respectively ) is explained using the cross-correlation functions of the propagating wav e packet with ground-state wave functions.