We demonstrate that unrestricted Hartree-Fock theory applied to electrons in a uniform potential has stable Wigner crystal solutions for rs≥1.44 in two dimensions and rs≥4.5 in three dimensions. The correlation energies of the Wigner crystal phases are considerably smaller than those of the fluid phases at the same density.
@article{arxiv.0909.5498,
title = {Unrestricted Hartree-Fock theory of Wigner crystals},
author = {J. R. Trail and M. D. Towler and R. J. Needs},
journal= {arXiv preprint arXiv:0909.5498},
year = {2009}
}