RECURRENCE RELATIONS FOR THE EVALUATION OF ELECTRON REPULSION INTEGRALS OVER SPHERICAL GAUSSIAN FUNCTIONS

Recurrence relations are derived for the evaluation of two-electron re pulsion integrals (ERIs) over Hermite and spherical Gaussian functions . Through such relations, a generic ERI or ERI derivative may be reduc ed to ''basic'' integrals, i.e., true and auxiliary integrals involvin g only zero angular momentum functions. Extensive use is made of diffe rential operators, in particular, of the spherical tensor gradient Y(l )m(del). Spherical Gaussians, being nonseparable in the x, y, and z co ordinates, were not included in previous formulations. The advantages of using spherical Gaussians instead of Cartesian or Hermite Gaussians are briefly discussed. (C) 1993 John Wiley & Sons, Inc.