Hydrogen-rare gas interactions and Raman line shapes

Employing the recent XC(fit) intermolecular potential for H-2-Ar, we have p resented the results of the spectral parameters for the D-2-Ar Raman Q(1) b ranch, obtained from quantum mechanical close-coupled calculations. While t he theoretical line shifts of the polarized Raman spectra were found to agr ee with experiments, the corresponding widths were smaller than the measure d values by as much as 56%. We observed that the shifts and the widths depe nd on the vibrational dependence of the potential in their own separate way s, and our results suggested that the anisotropic vibrational dependence of the XC(fit) potential requires improvement, in conjunction with further fi ne-tuning of the isotropic part. Even though there is no experimental data for comparison, we have computed the line-mixing parameters of the polarize d Raman Q(1) branch, as well as the depolarized line widths and shifts for the Q(1)(j) lines. These results showed the same trends as the correspondin g ones for D-2-He.