MOLECULAR POLARIZABILITIES IN GASES AND LIQUIDS - INDUCED INTERACTIONS IN LIQUIDS - CALCULATIONS FROM CLASSICAL AND REVISED EXPRESSIONS

A comparison of the optical mean molecular polarizability <(alpha)over bar> and of the molecular polarizability anisotropy gamma(2) between gases and liquids, based on reliable measurements is made on twelve co mpounds. The determinations through the spherical cavity model indicat e slight decreases in <(alpha)over bar> and large deviations in gamma( 2) values from gases to liquids. A large decrease in gamma 2 values is observed when a corrected formula is used. It is shown by a simple el ectrostatic bimolecular interaction scheme that the apparent decreases observed in liquids are due to the short distance mutual interactions between the molecular dipole moments induced by the electric field of the incident optical wave. Detailed calculations are made by using th e ellipsoidal cavity model, which includes the induced interactive eff ects in a consistent macroscopic way. They lead to <(alpha)over bar> a nd gamma(2) values in liquids which are in agreement with the gas valu es in the case of a corrected light scattering formula. On the contrar y the classical formula gives inconsistent high values. These results show the prevalence of the previously established corrected formula, a nd bring informations about the origin of the apparent deviations from gases to liquids.