Line mixing effects in the 15 mu m Q-branches of CO2 in helium: Theoretical analysis

Starting from the formalism proposed by Green [J. Chem. Phys 90, 3603 (1989)] and based on the infinite order sudden approximation, we describe here an improved model, based on the energy corrected sudden approximation, which allows the calculation of all types of coupling cross-sections i.e. for stretching as well as bending bands of CO2 starting from a single set of basic rates. Predictions of that model with various experiments made on stretching bands in samples of CO2 in He had been shown to be rather good. The present paper shows that it also predicts the evolution of bending bands in these samples reasonably well, particularly that of Q branches, over a wide range of perturber density. Copyright (C) 1996 Elsevier Science Ltd