The extended Hubbard Hamiltonian on a bcc lattice is studied at half-filing and for finite hopping between next-nearest-neighbours, in the mean-field approximation. An ionic insulating broken-symmetry phase is predicted to occur for any hydrogenoid bce solid in the density range 1.0 < r(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 region of 100 GPa.
Are light alkali metals still metals under high pressure?
SIRINGO, Fabio;ANGILELLA, Giuseppe Gioacchino Neil
1997-01-01
Abstract
The extended Hubbard Hamiltonian on a bcc lattice is studied at half-filing and for finite hopping between next-nearest-neighbours, in the mean-field approximation. An ionic insulating broken-symmetry phase is predicted to occur for any hydrogenoid bce solid in the density range 1.0 < r(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 region of 100 GPa.File in questo prodotto:
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