Benchmark Values for Two-Center Coulomb Integrals over Slater-Type Orbitals

摘要

The Lowdin alpha-function method, in which displaced orbitals are expanded in aninfinite series of spherical harmonics, is implemented for Slater-type orbitals using a commercial computer algebra program, Mathematica. The program, which is included, generates a C matrix with integer elements that characterizes our approach to multicenter molecular integrals. The general two-center, two-electron Coulomb repulsion integral is produced analytically with a finite number of terms. Each Coulomb formula may be evaluated to arbitrary precision, since Mathematica works with integer arithmetic. Hence, cancellation errors can be overcome.... Computer algebra, Coulomb integral, Slater-type orbital.