Numerical Calculations Of Two-Center Overlap Integrals With The Same Screening Parameters Over STO

We present a program for the evaluation of overlap integrals with the same screening parameters over Slater type orbitals (STOs), which are one of the types of exponential type orbitals (ETOs), and for this aim we have used Mathematica 7.0. The program is based on a number of general formulas for molecular integrals with STO basis functions. These formulas consist of real spherical harmonics, Gegenbauer coefficients and Gaunt coefficients which are a considerable importance for computations to large values of quantum numbers n, l, m. Moreover, all coefficients are given in terms of factorials. In this paper, our numerical results for large values of quantum numbers are agreed with the results of literature.