  A pressure-induced simultaneous metal-insulator transition (MIT) and
structural-phase transformation in lithium hydride with about 1% volume
collapse has been predicted by means of the local density approximation (LDA)
in conjunction with an all-electron GW approximation method. The LDA wrongly
predicts that the MIT occurs before the structural phase transition. As a
byproduct, it is shown that only the use of the generalized-gradient
approximation together with the zero-point vibration produces an equilibrium
lattice parameter, bulk modulus, and an equation of state that are in excellent
agreement with experimental results.
