Materials Data on Mg(NiO2)2 by Materials Project

Mg(NiO2)2 is Spinel structured and crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Mg2+ is bonded to four O2- atoms to form MgO4 tetrahedra that share corners with twelve NiO6 octahedra. The corner-sharing octahedra tilt angles range from 55–62°. All Mg–O bond lengths are 1.99 Å. There are four inequivalent Ni3+ sites. In the first Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent MgO4 tetrahedra and edges with six NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.94–2.08 Å. In the second Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent MgO4 tetrahedra and edges with six NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.96–2.04 Å. In the third Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent MgO4 tetrahedra and edges with six NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.94–2.04 Å. In the fourth Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent MgO4 tetrahedra and edges with six NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.95–2.04 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms. In the fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Ni3+ atoms.