Formulas are developed for evaluating the three-electron integrals, which a
ppear in the transcorrelated method using a frozen Gaussian geminal. First,
we derive expressions with intermediates, in which the angular momentum in
dices of the inter-electronic operators are temporarily increased. Followin
g the inspection on the factorization property, we further derive more stra
ightforward recurrence relations corresponding to the Obara-Saika one for e
lectron repulsion integrals. It is shown that the relations can be applied
outside the contraction loops over geminal primitives by introducing three-
indexed auxiliary integrals. (C) 2000 Elsevier Science B.V. All rights rese
rved.