Elasticity properties of the low-compressible material ReB2

By means of ab initio plane-wave pseudopotential density functional theory, the equilibrium structure parameters, the bulk module and shear module, and the elastic constants of ReB2 have been investigated. Our results are consistent with the experimental and previous theoretical data. Comparing it with other hard materials, we conclude that ReB2 is a sort of low-compressible material. The parameters of anisotropy are all larger than 1, which indicates that the hexagonal ReB2 is anisotropic. The elastic constant c 33 is larger than c 11 at all pressure points, which shows that the compressibility of ReB2 in the z direction is larger than that in the x and y directions.