Abstract
The so-called local-density approximation (LDA) plus the multiorbital mean-field Hubbard model (LDA+U) has been implemented within the all-electron projector augmented-wave method, and then used to compute the insulating antiferromagnetic ground state of NiO and its optical properties. The electronic and optical properties have been investigated as a function of the Coulomb repulsion parameter U. We find that the value obtained from constrained LDA eV) is not the best possible choice, whereas an intermediate value eV) reproduces the experimental magnetic moment and optical properties satisfactorily. At intermediate U, the nature of the band gap is a mixture of charge transfer and Mott-Hubbard type, and becomes almost purely of the charge-transfer type at higher values of U. This is due to the enhancement of the oxygen states near the top of the valence states with increasing U value.
- Received 20 January 2000
DOI:https://doi.org/10.1103/PhysRevB.62.16392
©2000 American Physical Society