Calculation of radial couplings between approximate wavefunctions in atomic collisions

Abstract

A method is presented for the calculation of the radial coupling matrix elements which occur in the molecular approach to atomic collisions. The formalism is based on the earlier work of Bratos (1958) and provides a local method of evaluating analytically radial couplings between approximate wavefunctions when a Gaussian basis is used. The cases of CI and SCF molecular calculations are treated explicitly. Some examples of strong and weak radial couplings are chosen to show the efficiency of the procedure and an approximate formula is tested for the case of coupling between SCF orbitals.