Collision-induced vibrational polarizability and mixed second refractivityvirial coefficients B-R(ab): an experimental study of the SF6-rare gas mixtures

Mixed second refractivity virial coefficients B-R(ab)(omega) are determined in the infrared spectral range from the analysis of the buffer gas-induced intensity redistribution in the nu(3) absorption band at omega approximate to 930 cm(-1) of (SF6)-S-34 perturbed by the rare gases Ar, Kr, and Xe at relative densities up to 140 Amagat. The values of the refractivity virial coefficients are found to be several orders of magnitude greater than those observed in the spectral regions far removed from single-photon resonances . The undamped dynamic dipole-induced-dipole (DID) model is shown to qualit atively correctly reproduce the observed unusual dispersion of the B-R(ab)( omega) functions. A new estimate of the integrated band intensity S(nu(3)) of SF6 is also obtained.