A simple numerical model of vibrational energy transfer in polyatomic gases

Abstract

A numerical procedure is developed for the accurate modelling of vibrational-vibrational and vibrational-translational energy transfer in molecular gases. The harmonic approximation necessary for an analytical solution is unnecessary and experimentally observed level energies are used. Rate constants, deduced by curve fitting results from this model to thermal lens data, are significantly different from those deduced from an analytical solution, e.g. for CO2,k1=350 Torr-1 s-1 and k2 = 370 Torr-1 s-1 for the scheme CO2(010) + CO2(000) ⇌ CO2(000) + CO2(000), ΔH = - 667 cm-1 and CO2(001) + CO2(OOO) ⇌ CO2 (030) + CO2(000), ΔH = -417 cm-1, where k1 and k2 are the rate constants for the forward processes. © 1993.