Metastable conducting solid hydrogen at high pressures.*

The posibility of formation of metastable metallic hydrogen at normal pressure was predicted in [1]. In the present work, the density functional theory is applied for the calculation of the equation of state, the pair correlation function and density of states of solid hydrogen in the region of the possible formation of the conducting phase. A hysteresis of the dependence of pressure on density is observed in the pressure range from 350 GPa to 625 GPa. During compression, the transition of molecular hydrogen with the C2/c symmetry to a conducting atomic state with the C222₁ symmetry through an intermediate conducting molecular phase with Cmca-4 symmetry is observed. The results of calculation of the band structure of the molecular state Cmca-4 point to the semimetalic mechanism of conductivity. The possibility of the existence of conductive atomic solid hydrogen with P2₁/c symmetry under expansion up to a pressure of 350 GPa is shown.

1. Kagan, Yu.; Brovman, E. G. // Sov. Phys. Usp. 1971, 14, 809 - 811.