Monte Carlo calculation of interaction energies for van der Waals complexes

Abstract
The electronic structure Schrödinger equation is solved approximately to obtain the interaction energies for the van der Waals complexes of spin-polarized H2 and H3 and the closed shell systems of He2 and He3. Both two- and three-body components of the interaction energies are reported. The interaction energies are obtained through variational and Green's function Monte Carlo calculations using optimized wavefunctions that properly correlate the electrons.