Materials Data on Ca3Ni2O7 by Materials Project

Abstract

Ca3Ni2O7 is Orthorhombic Perovskite-like structured and crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.34–2.63 Å. In the second Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.28–2.48 Å. Ni4+ is bonded to six O2- atoms to form corner-sharing NiO6 octahedra. The corner-sharing octahedra tilt angles range from 24–25°. There are a spread of Ni–O bond distances ranging from 1.92–1.95 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent Ca2+ and one Ni4+ atom. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+ and two equivalent Ni4+ atoms. In the third O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+ and two equivalent Ni4+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+ and two equivalent Ni4+ atoms.