On the long-range configuration interaction between ionic and covalent states

Abstract

The problem of long-range configuration interaction between ionic and covalent states is considered. The existing methods for calculation of this interaction are discussed. An asymptotically exact expression for the long-range configuration interaction at the crossing point of diabatic ionic and covalent potentials is derived. Using this expression the adiabatic energy splitting at the crossing point for H*+H, M+H, and M+O systems (M = alkali atom) is calculated. The results are compared with those obtained by LCAO and variational calculations.