On the Relation between Population Kinetics and State-to-State Rate Coefficients for Vibrational Energy Transfer

Abstract

Abstract:The relation between time-dependent population of vibrational state and collision-induced state-to-state rate coefficients is discussed within the Landau-Teller kinetic equations for the relaxation of harmonic oscillators in a heat bath. In particular, the increase of the populations in the first and the second vibrational state of an initially cold oscillator shows a considerable variety of its relation to a single Landau-Teller state-to-state rate coefficient. It is suggested that this variety should be kept in mind when experimental studies of the relaxation of specific level are analyzed.

Electronically nonadiabatic mechanism of the vibrational relaxation of NO in Ar: Rate coefficients from ab initio potentials and asymptotic coupling

“…The following conclusions can be drawn from above: 35 Considering the approximations inherent in the asymptotic estimation of the theoretical coupling coefficient and the error limits (±30%) of the measured rates, the agreement between experiment and theory appears quite satisfactory. We also note that Coriolis and spin-orbit interactions at this temperature make comparable contribution to the nonadiabatic coupling, with the latter dominating at lower temperatures.…”

“…We, therefore, identify LT k 10 (NO-Ar) with a scaled rate coefficient LT k 10 (O 2 -Ar) (we tolerate possible effects of the small anisotropy and also the difference between the SSH rate coefficients on the V (R, θ) and V (R, θ) PES for the NO-Ar collisions). The scaling of LT k 10 (O 2 -Ar) to LT k 10 (NO-Ar) uses the dependence of T LT , T V , and A SSH on the vibrational frequency ω of the diatomic molecule, [33][34][35][36] i.e.,…”