Theoretical investigation of the electronic structure, elastic, dynamic properties of intermetallic compound NiBe under pressure

Abstract

From the beryllide group, NiBe is a hybrid material of CsCl (B2) type structure and presents a large range of stoichiometry. In this paper, we have studied the structural, electronic, elastic, and dynamic properties of NiBe intermetallic compound under pressure by performing ab initio density functional theory using the Cambridge Serial Total Energy Package (CASTEP). In B2 structure, we have obtained the lattice constant ( $${A}_{\mathrm {0}}$$ ), equilibrium volume ( $${V}_{\mathrm {0}}$$ ), bulk modulus ( $${B}_{\mathrm {0}}$$ ) and its pressure derivative ( $${B}_{0}$$ ’) and elastic constants. We have quantitatively analyzed the band structure and the corresponding density of states (DOS). We have also estimated the mechanical stability and brittle/ductile behaviors of this compound based on the computed elastic constants. It is found that this structure is stable between 0 and 50 GPa pressure for NiBe compound. Finally, the changing degree of anisotropy with pressure was analyzed in three and two dimensions.