Madelung energy of the wigner crystal on lattices with non-equivalent sites

Abstract A recent calculation for the Wigner crystal on non-Bravais lattices is found to violate an exact lower bound for the potential energy. The existence in non-Bravais lattices of inequivalent sites is shown to be at the origin of the erroneous prediction of the stability of the Wigner crystal on the perovskite structure. Once the energy per particle is correctly evaluated, the BCC lattice remains the most stable energetically.