The ground-state energy of a system of hard-sphere bosons of diameter $\sigma$ is calculated by a variational method using a Jastrow wave-function for the fluid phase and a "localized" Jastrow times a Gaussian wave function for the solid phase. The transition densities are ${\rho }_{\mathrm{fluid}}=0.23\mathrm{}\pm 0.02$ particles/${\mathrm{\sigma }}^3$ and ${\rho }_{\mathrm{solid}}=0.25\mathrm{}\pm 0.02$ particles/${\mathrm{\sigma }}^3$.

DOI:https://doi.org/10.1103/PhysRevA.3.776