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

The multicenter charge-density expansion coefficients [I. I. Guseinov, J Mol Struct (Theochem) 417, 117 (1997)] appearing in the molecular integrals with an arbitrary multielectron operator were calculated for extremely large quantum numbers of Slater-type orbitals (STOs). As an example, using computer programs written for these coefficients, with the help of single-center expansion method, some of two-electron hive-center Coulomb and four-center exchange electron repulsion integrals of Hartree-Fock-Roothaan (HFR) equations for molecules were also calculated. Accuracy of the results is quite high for the quantum numbers, screening constants, and location of STOs. (C) 2000 John Wiley & Sons, Inc.