Materials Data on Ca(NiO2)2 by Materials Project

Abstract

NiOCaONiO2 crystallizes in the triclinic P-1 space group. The structure is two-dimensional and consists of two nickel dihydroxide molecules and one NiOCaO sheet oriented in the (0, 1, -1) direction. In the NiOCaO sheet, Ca2+ is bonded in a 1-coordinate geometry to three O2- atoms. There are a spread of Ca–O bond distances ranging from 1.40–2.43 Å. There are two inequivalent Ni3+ sites. In the first Ni3+ site, Ni3+ is bonded in a linear geometry to two equivalent O2- atoms. Both Ni–O bond lengths are 1.41 Å. In the second Ni3+ site, Ni3+ is bonded in a distorted linear geometry to two equivalent O2- atoms. Both Ni–O bond lengths are 1.34 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Ca2+ and one Ni3+ atom. In the second O2- site, O2- is bonded in a distorted L-shaped geometry to one Ca2+ and one Ni3+ atom.