Ab initio calculations of cohesive and structural properties of the alkali-earth oxides

We have performed ab initio self-consistent calculations of the standard cohesive properties (equilibrium lattice parameters, binding energies and bulk moduli) of the four alkali-earth oxides (MgO, CaO, SrO and BaO) having the B1 (NaCl-like) phase under normal temperature and pressure conditions. We have also studied the relative stability of the B1 and B2 (CsCl-like) phases, and the behaviour, under pressure of these crystals (equations of state, transition pressures and changes of volume for the structural phase transition B1 --> B2). All the calculations were performed in the framework of the density-functional theory by a method which allows the direct calculation of the ground-state electron density of a system without the preliminary determination of its wavefunctions and energy eigenvalues.