Elastic anisotropy of OsB2 and RuB2 from first-principles study

The elastic anisotropy of the potential low compressible and hard materials OsB2 and RuB2 were studied by first-principles investigation within density functional theory. The structure, elastic constants, bulk modulus, shear modulus, Poisson's ratio and Debye temperature have been calculated within both local density approximation (LDA) and generalized gradient approximation (GGA). The results indicated that the calculated bulk modulus and shear modulus were in good agreement with the experimental and previous theoretical studies. The calculated elastic constants anisotropic factors and directional bulk modulus showed that OsB2 and RuB2 possess high elastic anisotropic.