INTERACTION-INDUCED POLARIZABILITY INVARIANTS AND THE INTERATOMIC POTENTIAL OF THE MERCURY DIATOM

Analytical models of the invariants (trace and anisotropy) of the diat om polarizability tensor are formulated that differ from existing mode ls by the suppression of the classical long-range components at close range (''damping''). Such damping is imperative in diatomic systems wh ere the long-range polarizability terms are relatively large and/or th e collision energies are high so that substantial penetration of the e lectronic shells of the colliding atoms takes place, e.g., for collisi on-induced light scattering by mercury vapor at high temperatures. Whe n a small number of physically meaningful parameters of the polarizabi lity models are properly adjusted, the binary trace and anisotropy col lision-induced spectra of mercury vapor are closely reproduced from th eory in all details. An improved model. of the Hg-Hg interaction poten tial, which reproduces the existing: bound mercury dimer slates as wel l as the viscosity data, includes a similar damping term fur suppressi on of the dispersion part at close range. (C) 1998 American Institute of Physics.