Elasticity of hexagonal BeO

We study the elastic properties, electronic structure, and equation of state of BeO using a first-principles pseudopotential method within the gradient-corrected approximation of the density functional theory. Comparison of the calculated and experimental properties of BeO shows good agreement for all the properties studied here: ground-state structure, linear and bulk compressibilities, and elastic moduli. Calculations are also performed with the local density approximation and the differences in elastic properties are interpreted in terms of a uniform compression. Analysis of the pressure effect on the lattice parameters and on the atomic coordinates shows that the structure changes are close to isotropic from zero to 100 GPa.