Accurate high-energy electron diffraction measurements of structure
factors of NiO have been carried out to investigate how strong correlations
in the Ni 3d shell affect electron charge density in the interior area
of nickel ions and whether the ab initio approaches to the electronic structure
of strongly correlated metal oxides are in accord with experimental observations.
The generalized gradient approximation and the local spin density approximation
corrected by the Hubbard U term are found to provide the closest match
to experimental measurements. The comparison of calculated and observed
electron charge densities shows that correlations in the Ni 3d shell suppress
covalent bonding between the oxygen and nickel sublattices.
Physical Review B, 61 2506-12, 2000.
Max-Planck Institut für Festkörperforschung;
Postfach 80 06 65 D-70506 Stuttgart
