ON THE INFLUENCE OF RARE-GAS ATOM-CHLORINE ION POTENTIALS ON THE GROUND-STATE RG-CL-2 INTERACTIONS

An atom-atom model is used to evaluate the effect of ion-pair states o f Cl-2 on the ground state Rg-Cl-2 (Rg = He, Ne, Ar) potentials for th e linear geometry. For consistency, the ab initio RgCl(+/-) potentials are calculated with an accuracy equivalent to that for the total syst em. It is found that using only covalent (RgCl) and ionic diatomic pot entials, the direct ab initio results cannot be adequately reproduced for any Rg-Cl-2 system studied. Relevant nonadditivity of the charge-i nduced dipole interaction, the induced dipole-induced dipole interacti on, and the connection between different Legendre polynomial represent ations of the interaction potential between S- and D-state atoms are c onsidered. (C) 1998 Elsevier Science B.V. All rights reserved.