Correlation effect in spectral line shape from the Doppler to the collision regime

The spectral line shape model recently proposed by the present authors [J. Chem. Phys. 109, 8283 (1998)] is extended in order to account for correlati on between velocity- and phase-changing collisions. The possible additional source of asymmetry due to the finite duration of collision is also includ ed. In this implemented form, the model is consistent with previous exhaust ive experimental studies in the collision regime for H-2-rare gases and H-2 -nitrogen mixtures and has been shown to also accurately describe the obser ved spectral features at lower pressure for H-2-Ar. It should be pertinent for various other molecular systems in a wide range of pressure and tempera ture, in particular for optical diagnostics. (C) 1999 American Institute of Physics. [S0021-9606(99)01927-3].