On the calculation of arbitrary multielectron molecular integrals over slater-type orbitals using recurrence relations for overlap integrals. II. Two-center expansion method

Abstract

Using expansion formulas for the charge-density over Slater-type orbitals (STOs) obtained by the one of authors [I. I. Guseinov, J Mol Struct (Theochem) 1997, 417, 117] the multicenter molecular integrals with an arbitrary multielectron operator are expressed in terms of the overlap integrals with the same screening parameters of STOs and the basic multielectron two-center Coulomb or hybrid integrals with the same operator. In the special case of two- electron electron-repulsion operator appearing in the Hartree-Fock-Roothaan (HFR) equations for molecules the new auxiliary functions are introduced by means of which basic two-center Coulomb and hybrid Integrals are expressed. Using recurrence relations for auxiliary functions the multicenter electron-repulsion integrals are calculated for extremely large quantum numbers. (C) 2001 John Wiley & Sons, Inc.