Hartree-Fock and density functional calculations of the elastic constants of CaO

The elastic constants of CaO have been investigated with the periodic ab in itio linear combination of atomic orbitals method implemented in the CRYSTA L program. The calculations have been done at the Hartree-Fock (HF) and den sity functional theory (DFT) levels. In this last case, different exchange- correlation potentials using a local or gradient correction of the electron ic density have been used. The experiment-theory comparison allows us to co nclude that the generalized gradient approximation (GGA) corrected DF is th e best scheme to reproduce the experimental elastic constants of CaO. (C) 2 001 Elsevier Science Ltd. All rights reserved.