Green’s-function Monte Carlo algorithm for the solution of the Schrödinger equation with the shadow wave function

An implementation of the Green’s-function Monte Carlo method, using a shadow wave function as the importance function, is presented. This implementation gives faster convergence and more stable random walks than previous versions. The method is used to calculate the ground-state energy and the radial distribution function g(r) of solid ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ at density ρ=0.0335 A${\mathrm{̊}}^{\mathrm{-}3}$. The results obtained are compared with the literature and with the experimental values.