A recently proposed computational scheme based on local increments has been applied to the calculation of correlation contributions to the cohesive energy of the CaO crystal. Using ab initio quantum-chemical methods for evaluating individual increments, we obtain ∼80% of the difference between the experimental and Hartree-Fock cohesive energies. Lattice constants corrected for correlation effects deviate by less than 1% from experimental values, in the case of MgO and CaO. © 1996 The American Physical Society.

• Received 29 May 1996

DOI:https://doi.org/10.1103/PhysRevB.54.13529