The three body correlation spectrum in collision induced light scattering by isotropic molecular gases

The three body correlation spectra in the collision induced light scattering by gaseous Ar, CH4, CF4 and SF6 at 295 K are reported. The zeroth and second frequency moments are compared with calculations based on a pairwise additive triplet cluster polarizability. It is found that the experimental results may be accounted for with the use of the first order dipole-induced dipole model for the polarizability. The spectra may be used to distinguish between the suitability of various intermolecular potentials; modern potentials give excellent results for Ar and CH4 and a Lennard-Jones 28-7 potential best describes the CF4 and SF6 spectra.