Materials Data on Ca(NiO2)2 by Materials Project

Abstract

Ca(NiO2)2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.37–2.48 Å. There are two inequivalent Ni3+ sites. In the first Ni3+ site, Ni3+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing NiO6 octahedra. The corner-sharing octahedra tilt angles range from 49–58°. There are a spread of Ni–O bond distances ranging from 1.97–2.02 Å. In the second Ni3+ site, Ni3+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing NiO6 octahedra. The corner-sharing octahedra tilt angles range from 49–58°. There are a spread of Ni–O bond distances ranging from 1.99–2.06 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Ca2+ and three equivalent Ni3+ atoms to form a mixture of distorted corner and edge-sharing OCa2Ni3 trigonal bipyramids. In the second O2- site, O2- is bonded to two equivalent Ca2+ and three Ni3+ atoms to form a mixture of distorted corner and edge-sharing OCa2Ni3 trigonal bipyramids. In the third O2- site, O2- is bonded to two equivalent Ca2+ and three equivalent Ni3+ atoms to form a mixture of distorted corner and edge-sharing OCa2Ni3 square pyramids. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Ca2+ and three Ni3+ atoms.