We have implemented the so-called local density approximation (LDA) plus th
e Hubbard parameter U method (LDA+U), in a formalism based on the projector
augmented wave (PAW) method and calculated the ground-state properties of
NiO and its optical properties. Good agreement with the measured ground-sta
te antiferromagnetic magnetic moment and optical properties are obtained fo
r U = 5 eV. The enhancement of the O 2p near the top of the valence states
increases with the value of U. At intermediate U, the nature of the band ga
p is a mixture of charge transfer and Ni d -> d excitations. (C) 2000 Elsev
ier Science B.V. All rights reserved.