Resolutions of the Coulomb operator: II. The Laguerre generator

We discuss a resolution of the Coulomb operator, r12-1=|ϕi〉〈ϕi|, into a one-particle basis. We show that the Laguerre polynomials generate a resolution with attractive computational properties and we apply it to the calculation of Coulomb and exchange energies in hydrogenic ions, the H2 molecule, and the Be atom. Rapid convergence is observed in all cases and a theoretical reason for this is discussed.