Materials Data on Ca2Cr2O5 by Materials Project

Abstract

Ca2Cr2O5 crystallizes in the orthorhombic Pbam 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 2.38–2.78 Å. Cr3+ is bonded to five O2- atoms to form corner-sharing CrO5 square pyramids. There are a spread of Cr–O bond distances ranging from 1.91–1.99 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Ca2+ and two equivalent Cr3+ atoms to form distorted OCa4Cr2 octahedra that share corners with eight equivalent OCa2Cr2 tetrahedra, edges with two equivalent OCa4Cr2 octahedra, and edges with two equivalent OCa2Cr2 tetrahedra. In the second O2- site, O2- is bonded to two equivalent Ca2+ and two equivalent Cr3+ atoms to form distorted OCa2Cr2 tetrahedra that share corners with four equivalent OCa4Cr2 octahedra, corners with four equivalent OCa2Cr2 tetrahedra, and an edgeedge with one OCa4Cr2 octahedra. The corner-sharing octahedra tilt angles range from 8–75°. In the third O2- site, O2- is bonded in a 6-coordinate geometry to four equivalent Ca2+ and two equivalent Cr3+ atoms.