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

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.