Pressure induced insulator-metal transition of solid LiH

Abstract

The equation of state and the electronic band structure of solid LiH have been calculated using the local-density functional theory with Ceperley and Alder's exchange-correlation potential in the muffin-tin approximation. The band gap is the direct gap with the X 1 minus; X′ 4 symmetries up to the band closing at V M =3.35 cm 3 mole −1. At further compression, the band crossing occurs between the state with the Z 1 symmetry and that of the Z 3 symmetry. The transition pressure of metallization is estimated to be P M =226 GPa. Using the Debye model, the zero-point pressure is also calculated with the Debye temperature theoretically determined. The Debye temperature of 7LiH at normal density is 1115 K in agreement with the experimental value 1190 ± 80 K.