Materials Data on Ca(NiO2)4 by Materials Project

Abstract

Ca(NiO2)4 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. Ca2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ca–O bond distances ranging from 2.45–2.89 Å. There are four inequivalent Ni+3.50+ sites. In the first Ni+3.50+ site, Ni+3.50+ 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 52–56°. There are a spread of Ni–O bond distances ranging from 1.84–1.99 Å. In the second Ni+3.50+ site, Ni+3.50+ 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 52–57°. There are a spread of Ni–O bond distances ranging from 1.86–2.03 Å. In the third Ni+3.50+ site, Ni+3.50+ 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 54–56°. There are a spread of Ni–O bond distances ranging from 1.84–1.99 Å. In the fourth Ni+3.50+ site, Ni+3.50+ 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 54–57°. There are a spread of Ni–O bond distances ranging from 1.85–2.01 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to three Ni+3.50+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and three Ni+3.50+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and three Ni+3.50+ atoms. In the fourth O2- site, O2- is bonded in a trigonal planar geometry to three Ni+3.50+ atoms. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ca2+ and three Ni+3.50+ atoms. In the sixth O2- site, O2- is bonded to two equivalent Ca2+ and three Ni+3.50+ atoms to form distorted edge-sharing OCa2Ni3 trigonal bipyramids. In the seventh O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Ca2+ and three Ni+3.50+ atoms. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ca2+ and three Ni+3.50+ atoms.