Evaluation of GTO molecular integrals

Methods for evaluating the function F_m(t) occurring in molecular integrals over Gaussian-type orbitals are reviewed and extended. Formulas based on Bessel function and continued-fraction expansions are analyzed. The recommended evaluation procedures, embodied in a portable computer program, involve Padé approximations for various argument intervals and use recursion in m. The program is economical in storage requirements and faster than those in current use.