Orientational averaging of rotational transition probabilities computed using the sudden approximation

Abstract

Rotational group methods are used to average the results of a semiclassical sudden approximation calculation of rotational transition probabilities over all molecular orientations. The orientation average removes the even Δm selection rule while not affecting that for j. Calculations presented are done for intermolecular potentials selected to represent the argon-nitrogen system. These show the transition probability for Δj=0, ±2 to be slightly reduced compared to the v ∥ z case. For b*>1.2, the angular averaged Pj′j are nearly identical to the parallel case.