Evaluation of two-electron integrals including the factors r(12)(k) exp(-gamma r(12)(2)) over Cartesian Gaussian functions
We present a practical scheme for the evaluation of nonstandard two-electron integrals including the factors r(12)(k) exp(-gammar(12)(2)) which have been appeared recently, where k greater than or equal to -1 is an integer. The method used throughout this paper is based on the highly efficient Head-Gordon and Pople (HGP) approach of evaluation of electron repulsion integrals (ERI). Thus only straightforward modifications of existing codes that employ HGP or HGP-PRISM scheme are necessary to implement our approach. (C) 2003 Elsevier B.V All rights reserved.
two-electron integrals damped-r-12 integrals hgp recurrence relations