Adiabatic polarization energy in a simple dense fluid

In this note we prey300505 sent the results of a calculation of the adiabatic electrostatic polarization energy, P⁺, of Xe⁺ in fluid Ar over the density range 0.1-1.4 g cm^-3. P₊ was expressed in terms of Lekner's screening function which, within the framework of the Kirkwood approximation, is determined by the (neutral) solute-solvent and the solvent-solvent pair correlation functions. The density dependence of P₊ can be quite well approximated (within ≈10%) by the Born charging energy with the effective ionic radius being identified with the effective hard-core diameter for the (neutral) solute-solvent separation. The P₊ data, together with experimental spectroscope results for the density dependence of the ionization potential of Xe and of CH₃I, result in preliminary information concerning the ground state energy of the quasi-free electron in fluid Ar over a wide density range.