DIELECTRIC-SPHERE-COUPLE MODEL FOR NOBLE-GAS PAIR POLARIZABILITY

A classical model of two interacting dielectric spheres (DS) in an electric field is proposed to calculate the trace and anisotropy of the polarizability tensor of a pair of isotropic molecules. The case of noble gases is treated. It is shown that the dielectric-sphere-couple anisotropy is quite close to the dipole-induced-dipole (DID) anisotropy, while the DS trace is significantly greater than the DID trace, even at long distances between the interacting spheres. These results are interpreted as being due to the non-negligible multipolar contributions to the trace. To examine the validity of the model, its predictions are compared with results of experiments (trace and anisotropy are responsible for many collision-induced optical phenomena or properties) and of self-consistent-field calculations.