SPECTRUM OF COLLISION-INDUCED SCATTERING - ROLE OF MULTIPOLAR POLARIZABILITIES

The collision-induced light scattering from fluids yields polarized I( nu ) intensities. The long tails at high Stokes and anti-Stokes frequencies observed in rayleigh spectra of tetrahedral molecules are attributed to multipolar effects. The model of conducting spheres allows one to compute the spectra and the ratio (Q//m//i//m( nu ) equals I( nu )/i( nu ) of these intensities by taking into account the multipolar effects to all orders. This ratio changes with frequency, contrary to he constant value ( equals 4/3) calculated in the first-order DID theory. The experimental ratio obtained in CF//4 and CH//4 presents an evolution similar to the computed value q(mim)( nu ).