Effect of internal fields on depolarized light scattering fromn-alkane gases

In this paper we extend the interacting site theory of optical response proposed by Applequist, Karl and Fung to molecules with internal degrees of freedom. We apply the theory to chain alkanes and calculate their polarizabilities. We find that the interacting site model agrees well with the experimental data on depolarized light scattering from small normal alkanes in the gas phase. Unlike the bond additive model, our model predicts the observed behaviour of the depolarization of the scattered light with the number of carbon-carbon bonds. We also discuss asymptotic behaviour of isotropic and anisotropic polarizabilities for long chains.