Calculated Collision-Induced Absorption Spectrum for He–Ar

Abstract

Computations (exact within the classical framework) are presented of the translational absorption spectrum for a model system of dissimilar rare-gas atoms chosen to simulate the He–Ar pair. The treatment makes use of the classical theory of Levine and Birnbaum. However, the procedure takes proper account of the nonlinear collision trajectories (evaluated on the basis of a realistic interaction potential derived from beam scattering experiments) and the theoretical form of the dipole-moment function (i.e., the ab initio computations of Matcha and Nesbet). The calculations reproduce the experimental (Bosomworth and Gush) line shape for He–Ar fairly well, provided the “dipole range parameter” is altered by some 7% from its ab initio value.