Semiempirical study of polyatomic rare gas halides: Application to the XenCl systems

Abstract
In order to calculate different electronic states in polyatomic rare gas–halogen systems, including ionic states with charge transfer, a semiempirical diatomics‐in‐ionic‐systems (DIIS) method is presented. In this method the Hamiltonian matrix elements are expressed in terms of diatomic potentials, except for those which are responsible for coupling between the ionic and neutral states. The coupling matrix elements are determined by fitting the diatomic transition moments. Calculations are performed for Xe2Cl, Xe3Cl, and Xe12Cl. The results reveal at least three quasistable ionic Xe+2Cl molecules. Such molecules can attract more Xe atoms, which are binded mainly by polarization forces.