On the modelling of absorption in the nu(3) band far wing of CO2 perturbedby 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 dependenc e can be thought to arise due to the finite volume of the molecules. Presen t work demonstrates that the perturber density variations of the CO2 absorp tion up to 1000 bars total pressure can be easily interpreted in terms of t he spectroscopic manifestation of a variety of van der Weals complexes form ing at elevated density. At least at high densities the van der Waals assoc iates prove to be the dominant contributors to observed absorption in the f ar wines. (C) 1999 Elsevier Science Ltd. All rights reserved.