A classical trajectory study of the high CH and CD overtones in benzene and perdeuterobenzene

Abstract

The intermolecular vibrational energy redistribution in high overtones of CH(D) stretching modes in benzene and perdeuterobenzene has been studied using classical trajectories. Using the exact kinetic energy and the best available potential energy surface for planar benzene, the rapid decay of these local modes is calculated to be in reasonable quantitative agreement with experimental lifetimes. The long time dynamics of benzene is found to be characterized by periodic energy transfer between CH stretching local modes via a 2:1 Fermi resonance with normal ring modes. Preferential energy transfer between para CH local modes is observed.