Vibrational relaxation of HCI as a function of xenon density: The role of HCI-Xe complexes

A treatment of the effect of vibrational predissociation of van der Waals complexes on vibrational relaxation rates [Chem. Phys. 29, 253 (1978)] has been extended by including V-V energy transfer between complexed and uncomplexed species and the possibility of different V-T/R relaxation rates for complexed and uncomplexed species. These modifications allow us to reproduce experimentally observed relaxation data for HCl(v=1) over two orders of magnitude in xenon density. The dependence of the vibrational relaxation rate on density is discussed as are the implications of the observed behavior on isolated binary collision formulations of vibrational energy relaxation processes.