Semiclassical modeling of infrared pressure-broadened linewidths:: A comparative analysis in CO2-Ar at various temperatures

A novel semiclassical approach, which makes use of the exact trajectory implemented within the Robert-Bonamy formalism, is employed for modeling infrared pressure-broadened linewidths. As a prototype, the carbon dioxide molecule perturbed by argon is examined in the temperature range 160-760 K, for which various measurements and computations are available. For a meaningful comparison with previous theoretical works done with both semiclassical and quantum approaches, the ab initio intermolecular potential surface of Parker [J. Chem. Phys. 64, 1668 (1976)] is used. Our values are found to be in agreement with up-to-date experimental data at all temperatures studied. (C) 2001 American Institute of Physics.