First-principles calculations for elastic properties of OsB2 under pressure

The structure, elastic properties and elastic anisotropy of orthorhombic OsB2 are investigated by density functional theory method with the ultrasoft pseudopotential scheme in the frame of the generalized gradient approximation (GGA) as well as local density approximation (LDA). The obtained structural parameters, elastic constants, elastic anisotropy and Debye temperature for OsB2 under pressure are consistent with the available experimental data and other theoretical results. It is found that the elastic constants, bulk modulus and Debye temperature of OsB2 tend to increase with increasing pressure. It is predicted that OsB2 is not a superhard material from our calculations.