Magnetic ground state of metallic hydrogen and lithium in the low-density limit

The nature of the magnetic instabilities in an electron gas at low densities is investigated by means of local spin-density determinations of the electronic and magnetic properties of monoatomic alkali-metal materials in the low-density limit. The total energy and band structures of the paramagnetic, ferromagnetic, and antiferromagnetic phases of H and Li were calculated using the linearized muffin-tin orbital method and the full-potential linearized augmented-plane-wave method. The different instabilities and the corresponding metal-insulator transitions are discussed. A stable antiferromagnetic phase is obtained for metallic H, and a stable ferromagnetic phase for metallic Li. A Stoner-factor calculation for all the alkali metals shows the exceptional behavior of H.