Ground State of Liquid He⁴

The properties of the ground state of liquid He⁴ are studied using a variational wave function of the form Π_i<jf(r_ij). The Lennard-Jones 12-6 potential is used with parameters determined from the gas data by deBoer and Michiels. The configuration space integrals are performed by a Monte Carlo technique for 32 and 108 atoms in a cube with periodic boundary conditions. With f(r)=exp[-(2.6 Å/r)⁵], the ground-state energy is found to be -0.78 × 10^-15 ergs/atom, which is 20% above the experimental value. The liquid structure factor and the two-particle correlation function are in reasonably good agreement with the x-ray and neutron scattering experiments.