On the Evaluation of Integrals Occurring in the Theory of the Correlated Electronic Wave Functions

It can be shown that the simplest generalization of the Hylleraas method for atoms with arbitrary number of electrons leads to integrals of six and nine dimensions, respectively, where the interelectronic distances occur in the integrands. The purpose of the present paper is to show that the nine-dimensional integrals can be treated by a similar procedure to that which was suggested for the evaluation of the six-dimensional integrals by Hylleraas and Breit.