  This letter extends my recent paper on antiferromagnetic NiO [Structural
Distortion Stabilizing the Antiferromagnetic and Insulating Ground State of
NiO, Symmetry 2020, 12(1), 56] by including also the paramagnetic phase of this
compound. I report evidence that paramagnetic NiO possesses a narrow, roughly
half-filled energy band that produces a nonadiabatic atomic-like motion
providing the basis for a Mott insulator in the paramagnetic phase. While the
atomic-like motion operating in the antiferromagnetic phase is adapted to the
symmetry of the antiferromagnetic state, in the paramagnetic phase the related
localized states are represented by optimally localized Wannier functions
possessing the full fcc symmetry of paramagnetic NiO. The nonadiabatic Wannier
states are twofold degenerate, have d-like symmetry and are situated at the Ni
atoms.
