Materials Data on NiO2 by Materials Project

Abstract

NiO2 crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are two inequivalent Ni4+ sites. In the first Ni4+ site, Ni4+ is bonded to four O2- atoms to form corner-sharing NiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 57–58°. There is three shorter (1.85 Å) and one longer (1.90 Å) Ni–O bond length. In the second Ni4+ site, Ni4+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with three equivalent NiO4 tetrahedra and edges with four equivalent NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.85–1.99 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to three Ni4+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal pyramidal geometry to four Ni4+ atoms. In the third O2- site, O2- is bonded in a distorted T-shaped geometry to three equivalent Ni4+ atoms. In the fourth O2- site, O2- is bonded in a water-like geometry to two equivalent Ni4+ atoms.