On the Calculation of Multicenter Two-Electron Repulsion Integrals Involving Slater Functions

Abstract

Integral transforms are used to evaluate many-center two-electron repulsion integrals involving Slater s-type functions. The reduction of a general four-center integral of this type to a form convenient for computational purposes is presented. The technique described has the important advantage that all lesser many-center and one-center integrals can be obtained from the four-center case by proper choice of constants. The form of the result is such that simple single-precision numerical techniques yield rapid and accurate evaluations of many-center integrals. Several numerical examples are presented.