Materials Data on Mg(NiO2)2 by Materials Project

Abstract

Mg(NiO2)2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Mg2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Mg–O bond distances ranging from 2.19–2.41 Å. There are two inequivalent Ni3+ sites. In the first Ni3+ site, Ni3+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing NiO6 octahedra. The corner-sharing octahedra tilt angles range from 49–63°. There is four shorter (1.92 Å) and two longer (2.00 Å) Ni–O bond length. In the second Ni3+ site, Ni3+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing NiO6 octahedra. The corner-sharing octahedra tilt angles range from 49–63°. There are a spread of Ni–O bond distances ranging from 1.91–2.05 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Mg2+ and three equivalent Ni3+ atoms to form a mixture of distorted edge and corner-sharing OMg2Ni3 trigonal bipyramids. In the second O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Mg2+ and three Ni3+ atoms. In the third O2- site, O2- is bonded to two equivalent Mg2+ and three equivalent Ni3+ atoms to form a mixture of distorted edge and corner-sharing OMg2Ni3 square pyramids. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Mg2+ and three Ni3+ atoms.