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

The elastic constants of CaO have been investigated with the periodic ab initio linear combination of atomic orbitals method implemented in the CRYSTAL program. The calculations have been done at the Hartree-Fock (HF) and density functional theory (DFT) levels. In this last case, different exchange-correlation potentials using a local or gradient correction of the electronic density have been used. The experiment-theory comparison allows us to conclude that the generalized gradient approximation (GGA) corrected DF is the best scheme to reproduce the experimental elastic constants of CaO. (C) 2001 Elsevier Science Ltd. All rights reserved.