On the modelling of absorption in the ν3 band far wing of CO2 perturbed by argon

Recent experimental data show that the absorption in the far wings of nu(3) and 3 nu(3) absorption bands of CO2 in a mixture with Ar or He rare gases exhibit nonlinear perturber density dependence. Very roughly this dependence can be thought to arise due to the finite volume of the molecules. Present work demonstrates that the perturber density variations of the CO2 absorption up to 1000 bars total pressure can be easily interpreted in terms of the spectroscopic manifestation of a variety of van der Weals complexes forming at elevated density. At least at high densities the van der Waals associates prove to be the dominant contributors to observed absorption in the far wines. (C) 1999 Elsevier Science Ltd. All rights reserved.