Hartree–Fock and density functional calculations of the elastic constants of the alkaline-earth oxides: comparison with experiment

The periodic linear combination of atomic orbitals-self consistent field (LCAO-SCF) method was used to calculate the static elastic constants of MgO, CaO and SrO. The calculations have been made within the Hartree–Fock (HF) and the density functional (DF) levels of theory. In this last case, the exchange-correlation potential correcting the electronic density uses either local or gradient models. The different results of the calculations are compared with experiment and discussed according to the scheme of calculation adopted and the quality of the basis set (all-electron or effective core pseudopotential sets used for CaO).