EVALUATION OF MOLECULAR MULTICENTER INTEGRALS FOR SLATER-TYPE ORBITALS

An integral transform technique is suggested to evaluate the multicentre molecular integrals for Slater-type orbitals. For example, the two-electron-four-centre integral can be cast into a simple numerical integration over a three-dimensional space. The integrand contains a finite sum of spherical harmonics and spherical Bessel functions of order L whose arguments contain the complicated angular dependence of the geometry of the centres: L<or= Sigma ili,li being the angular quantum number of each individual orbital. A few examples are given.