Novel a b i n i t i o self-consistent-field approach to molecular solids under pressure. II. Solid H2 under high pressure

Abstract

As a test of our new ab initio approach to the study of molecular solids under pressure, the PV relations for solid H2 under high pressure were studied. Using a minimum basis set of Slater orbitals and a single determinant crystal wave function, we found the hexagonal closest packed structure to be more stable than the face-centered cubic, body-centered cubic, or Pa3 structures investigated. Structurally optimized calculations of the PV isotherm at 0 K for the hexagonal closest packed solid gave excellent agreement with extrapolated experimental data. Furthermore, the calculated vibron frequency shows an initial increase with increasing pressure followed by a decrease beginning at ∼0.5 Mbars, as has been previously seen experimentally.