Internuclear dependence of static dipole polarizability in diatomic molecules

A simple universal correlation and semi-empirical model are suggested to fit or predict the dependence of the isotropic and anisotropic dipole polarizabilities (or equivalently the parallel and perpendicular components of the polarizability) of diatomic species. Selected ab initio calculations of the polarizability for N2 and NH are presented to test the correlation. Its significance in estimating atom-diatom dispersion coefficients is illustrated for the ArN2 interaction.