Quasi-classical dynamics of benzene overtone relaxation on an ab initio force field: 30-mode models of energy flow and survival probability for CH(v=2)

Quasi-classical methods were employed to study energy transfer from the first CH stretching overtone in 30-mode benzene. The ipso out-of-plane CH bend is identified as an important conduit for energy flowing out of the CH chromophore and reaches a maximum in local mode energy before the ipso in-plane CH wag does. Local mode analyses of energy flow provide a detailed description of the mechanism of intramolecular vibrational relaxation in benzene. Data from survival probability calculations are in reasonable agreement with previous classical studies of planar benzene and on-going quantal studies of 30-mode benzene.