ANALYTICAL TREATMENT OF NUCLEAR MAGNETIC SHIELDING TENSOR INTEGRALS OVER EXPONENTIAL-TYPE FUNCTIONS

The present work concerns the analytical and numerical development of three-center molecular integrals over Slater-type functions (STFs) and B functions of the second order involving 1/r(N)(3) in the operator. These integrals appear in the analytic expression of the nuclear magnetic shielding tensor. The basis set of STFs is used to represent atomic orbitals. These STFs are expressed in terms of B functions, which are better suited to apply the Fourier transform method thoroughly developed by Steinborn group. Analytic expressions are obtained for the integrals of the second order involved in nuclear magnetic resonance shielding tensor over B functions. These expressions turned out to be similar to those obtained for the usual molecular multi-center integrals. Consequently, the numerical evaluation of the integrals under consideration will benefit from the work previously done on the molecular multi-center integrals.