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.Comment: LaTeX, 8 pages, 2 figures, accepted by Phys. Rev.