Electronic structure of lithium beryllium hydride

Hartree-Fock band-structure and cluster calculations have been performed to study the electronic structure of ${\mathrm{LiBeH}}_3$ in the cubic perovskite structure. The total energy, bulk modulus, band structure, density of states, charge densities, and x-ray structure factors are obtained. The energy minimum has been found for a lattice constant of 3.3 Å in the band calculation (3.2 Å in the cluster calculation), by far larger than the 2.545 Å proposed by Overhauser for a fcc superstructure of ${\mathrm{LiBeH}}_3$ and used in a previous augmented-plane-wave calculation. The hydride is found to be an insulator. The essential features of the band structure can be understood in terms of the energy band of the ${\mathrm{BeH}}_2$ planes present in the perovskite structure. A metal, and possible high-temperature superconductivity often envisioned for metallic hydrogen, could be obtained if beryllium is replaced by boron.