On the influence of rare gas atom–chlorine ion potentials on the ground state Rg–Cl2 interactions

An atom-atom model is used to evaluate the effect of ion-pair states of Cl2 on the ground state Rg–Cl2 (Rg=He, Ne, Ar) potentials for the linear geometry. For consistency, the ab initio RgCl± potentials are calculated with an accuracy equivalent to that for the total system. It is found that using only covalent (RgCl) and ionic diatomic potentials, the direct ab initio results cannot be adequately reproduced for any Rg–Cl2 system studied. Relevant nonadditivity of the charge–induced dipole interaction, the induced dipole–induced dipole interaction, and the connection between different Legendre polynomial representations of the interaction potential between S- and D-state atoms are considered.