Rotational-translational propagation effects in orientational molecular correlation functions

A theory of spectral distribution of the rotational molecular time correlation function for a system consisting of a linear molecule active in a given process and an atomic perturber has been developed. Within the framework of the proposed approach the coupling between the rotational and translational degrees of freedom due to anisotropic intermolecular interactions has been considered. In order to analyse the effect of the rotational level mixing and propagation the stationary phase method has been used. The theory has been shaped in such a way that its final formulae would form a fully numerically tractable procedure, capable of producing orientational parts of spectral profiles for collision-induced absorption and scattering processes, which might be used for the interpretation of experimental results. Numerical calculations have been performed for N2-Ar pairs and the properties of the resulting spectral distributions have been studied, with special attention paid to their dependence on the angular momentum quantum number J