Integrals over <b>B</b> functions basis sets. I. Three-center molecular integrals, a numerical study

Abstract

The evaluation of multicenter integrals for SCF computation with a Slater-type orbitals (STO’s) basis set can be performed by expanding the atomic orbitals over a B function basis set. This is commonly carried out by means of the so-called Fourier integral transform. However, in spite of the extreme simplicity in developing the formulas, several numerical difficulties have not been fully solved. In fact, the reliability of computational algorithms is highly dependent on the choice of numerical integration techniques that are used to evaluate the multiple integral occurring in the analytical expression of any given multicenter integral. Special attention is paid to this aspect of computation and efficient numerical strategies are proposed.