Density-functional theory of the metal-insulator transition

The spin-density-functional theory is used to investigate the phase transitions of electrons in a lattice of fixed point charges (a model first studied by Mott). We find a first-order metal-insulator transition at rₛ=2.84 and a second-order magnetic transition at rₛ=2.74. Results are presented for the magnetization and the spin susceptibility. Extrapolating our results for the case of donor impurities in silicon (neglecting disorder), we estimate that the first-order metal-insulator transition would not be observable above Tc≈50 mK.