Quantum calculations on the collisions of nonlinear triatomic molecules with atoms: Vibrational excitation in He+SO2(v1v2v3)

Abstract

The combined vibrational close‐coupling, rotational infinite‐order sudden quantum technique is extended to the calculation of vibrational excitation cross sections for the three‐dimensional collisions of atoms with nonlinear triatomic molecules. The method has been incorporated into a general computer program which should be applicable to many atom–nonlinear triatomic systems having realistic potential energy surfaces. Calculations on the He+SO₂(v₁v₂v₃) system are reported for four different potential energy surfaces. Various vibrational transition propensities are observed. The results are used to examine the validity of assumptions made by Siebert and Flynn on the dominant collision‐induced energy transfer pathways contributing to the fluorescence rate of the v₃ mode of SO₂.