A Quantum Chemical Approach to Cohesive Properties of NiO

We apply ab-initio quantum chemical methods to calculate correlation effects on cohesive properties of NiO, thereby extending a recently proposed scheme to transition metal oxides with partially filled $d$-bands. We obtain good agreement with experiment for the cohesive energy and show that the deviation of the lattice constant at the Hartree-Fock level is mainly due to van der Waals-like interactions. Correlations enhance the stability of the magnetic ground state found at the Hartree-Fock level.