Elasticity of hexagonal BeO

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