1995/11/29 by Fabio Siringo, Renato Pucci, Giuseppe G. N. Angilella
Physics and Astronomy · #cond-mat
published as High Pressure Research, 15 (1997) 255 · 12 REVTeX pages + 1 PostScript figures in 1 uuencoded+ compressed+tarred format; subm. to Phys. Rev. Lett
arxiv created 1995/11/29 · arxiv updated 2009/11/30
The extended Hubbard Hamiltonian on a bcc lattice is studied at half-filling and for a finite hopping between next-nearest-neighbours, in mean-field approximation. An ionic insulating broken-symmetry phase is predicted for any hydrogenoid bcc solid in the density range 1.0 < r sub s < 2.6. The occurrence of an ionic phase would explain the failure to achieve hydrogen metallization at high pressures. Moreover, a metal-insulator transition is expected for sodium in the 100 GPa region.