One-Center Two-Electron Integrals Arising in Electron-Ion Scattering Calculations

The two-electron integrals which arise in electron-atomic ion scattering theory are expressed as a finite sum of terms each involving a generalized hypergeometric function. We give what is believed to be the first finite expansion known for the exchange integral. The many well-known recursive and transformation features of the hypergeometric functions are then utilized to conveniently and accurately evaluate the integrals with few restrictions on the values of the parameters.