Use of Ground-State Energy Calculations in Determining the Helium-Helium Interaction

A variational Monte Carlo calculation of the ground-state energy of liquid He⁴ has been performed with a product wave function of a flexible analytic form using several different proposed pair potentials. The calculated ground-state energy, particularly its density dependence, depends sensitively on the form of the pair interaction potential used. The variational nature of the calculations is used to set limits on the depth of some of the proposed forms of the pair potential.