Analytical evaluations of exponentially correlated unlinked one-center, three- and four-electron integrals

摘要

We discuss an extension of theHylleraas configuration-interactionmethod by incorporation of an exponentiallyncorrelated term. The necessary unlinked one-center, three- and four-electron integrals are derived in a closednform. No three- or four-electron auxiliary integrals appear in the final expressions. The evaluation scheme is annextension of the recent development of Ruiz [J. Math. Chem. 46, 1322 (2009)]. The prescription of combiningndiverged integrals to retrieve a finite value is avoided in the present approach.