Coordinate representation of the McWeeny-Coulson wave function for the helium atom

The coordinate representation of the McWeeny-Coulson wave function for the helium atom is obtained in the form of an expansion in scalar tripolar spherical harmonics. The coefficients of the expansion, which are functions of the interparticle coordinates, are represented as a sum of terms admitting separation of variables. Analysis of the expansion constructed substantiates the presence of the Huelten correlation factor in the wave function as well as the appearance of Huelten orbitals.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 37–43, August, 1985.