Use of Guseinov's One-Center Expansion Formulae and Lowdin alpha Radial Function in Calculation of Two-Center Overlap Integrals over Slater Type Orbitals with Noninteger Principal Quantum Numbers

An efficient calculation algorithm is presented for two-center overlap integrals over noninteger n* Slater type orbitals in molecular coordinate system based on the use of Guseinov's one-center expansion formulae and Lowdin a radial function. These integrals are expressed in terms of overlap integrals of integer n Slater type orbitals. The analytical formulae offer the advantage of direct and efficient calculation of the two-center overlap integrals over noninteger n* Slater type orbitals without the use of numerical methods. Several numerical results obtained are presented to demonstrate the improvements in convergence rates.