First principles study of structural stability, electronic structure and mechanical properties of alkali beryllium hydrides ABeH3 (A=K, Rb, Cs)

Abstract

Ab initio calculations are performed to investigate the structural stability, electronic structure and mechanical properties of alkali beryllium hydrides ABeH3 (A=K, Rb, Cs) for three different crystal structures, namely orthorhombic (Pnma), monoclinic (P21/c) and triclinic (P−1). Among the considered structures monoclinic (P21/c) phase is found to be the most stable one for these hydrides at ambient condition. The electronic structure reveals that these hydrides are insulators. The calculated elastic constants indicate that these materials are mechanically stable at ambient condition.