JASTROW WAVE-FUNCTION OF YUKAWA BOSE FLUIDS - MONTE-CARLO COMPUTATION

We study with the variational method the ground state of bosons interacting with Yukawa potentials in the fluid phase near solidification. We show that the serious discrepancy in the short-range order which was found by Ceperley et al. between Jastrow variational and exact results is due to the presence in the Jastrow function of intermediate-distance correlations. These are density dependent, and we relate them to the zero-point motion of rotonlike excitations on the basis of analogy with hard-core systems. A simple one-parameter expression of these correlations is proposed for any Bose system in the fluid phase. A Jastrow wave function which includes such correlations is as good as a Hartree-Jastrow wave function for the solid phase, so that the variational method can now be used to determine reliably the solidification line. © 1979 The American Physical Society.