An effective Hamiltonian survey of the anharmonic vibrational state space of SCCl2 up to the dissociation energy.
We survey about 3.5 million feature states in the anharmonic state space of SCCl(2) to answer three questions: how sharp is the threshold for intramolecular vibrational energy redistribution (IVR), how do specific resonances and regions of state space contribute to the threshold, and how many undiluted spectral features (or localized eigenstates) persist as energy increases? As quantitative measures we use the dilution factor sigma, Heller's F, and e, which describes how close to the edge of state space a feature lies. We find that an IVR threshold can be identified and lies between 250 and 300 THz. The threshold is softened because different resonances act at different energies in different parts of state space. According to our calculation, about 1 in 10(3) feature states remains undiluted near the dissociation limit of SCCl(2). This fraction matches the number of sharp spectral features observed recently by experiment when symmetry and Franck-Condon factors are taken into account, and it is in agreement with an analytical model that predicts an increasing fraction of undiluted features as molecular size increases.
Department of Chemistry, University of Illinois, Urbana, Illinois 61822, USA.
Praveen D
PD
Chowdary
Martin
M
Gruebele