Numerical evaluation of three‐ and four‐center bielectronic integrals using exponential‐type atomic orbitals

Abstract

Three‐ and four‐center Slater orbital bielectronic integrals are evaluated by means of a complete function set. The method provides a series to approximate the bielectronic integrals. Their corresponding partial sums are analyzed in detail for 1s orbitals. The comparison with the Fourier transform–based method brings forth encouraging perspectives for the present approach. © 1995 John Wiley & Sons, Inc.

Implementation of atomic basis set composed of 1s Gaussian and 1s Slater-type orbitals to carry out quantum mechanics molecular calculations

“…Implementation of the mixed-type AO basis set follows the main strategies delineated in previous work. 7 To carry out the SCF calculation 11 a code was written in GAUSSIAN 386i programming language; all nonlinear parameter optimizations were Ž carried out with its OPTIMUM subroutine provided . with the package .…”

“…Table I shows that the numerical behavior of the partial sums is analogous to that found for the corre-sponding STOs. 7 All one-and two-center bielectronic integrals that mix both kinds of AOs are Ž . calculated using eq.…”

“…The application is performed on a very well-known system, lithium hydride, for which there are numerous and very accurate results. 5 In previous articles, 6,7 expansions for binary products of any given class of atomic orbitals were found by using an appropriate complete function set. Therefore, it is an alternative tool 8,9 to evaluate multicenter bielectronic integrals.…”