DOI: 10.17188/1321282
title: Materials Data on ZnCrO2 by Materials Project

description: ZnCrO2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Cr2+ sites. In the first Cr2+ site, Cr2+ is bonded to five O2- atoms to form CrO5 square pyramids that share corners with four CrO5 square pyramids, corners with four ZnO5 trigonal bipyramids, edges with two equivalent CrO5 square pyramids, and an edgeedge with one ZnO5 trigonal bipyramid. There are a spread of Cr–O bond distances ranging from 1.99–2.19 Å. In the second Cr2+ site, Cr2+ is bonded to five O2- atoms to form CrO5 square pyramids that share corners with four CrO5 square pyramids, corners with two equivalent ZnO5 trigonal bipyramids, edges with two equivalent CrO5 square pyramids, and a faceface with one ZnO5 trigonal bipyramid. There are a spread of Cr–O bond distances ranging from 1.92–2.16 Å. In the third Cr2+ site, Cr2+ is bonded to five O2- atoms to form distorted CrO5 square pyramids that share corners with four CrO5 square pyramids, corners with two equivalent ZnO5 trigonal bipyramids, edges with two equivalent CrO5 square pyramids, and a faceface with one ZnO5 trigonal bipyramid. There are a spread of Cr–O bond distances ranging from 1.92–2.15 Å. In the fourth Cr2+ site, Cr2+ is bonded to five O2- atoms to form CrO5 square pyramids that share corners with four CrO5 square pyramids, corners with four ZnO5 trigonal bipyramids, edges with two equivalent CrO5 square pyramids, and an edgeedge with one ZnO5 trigonal bipyramid. There are a spread of Cr–O bond distances ranging from 1.99–2.19 Å. There are four inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded to five O2- atoms to form ZnO5 trigonal bipyramids that share corners with six CrO5 square pyramids, an edgeedge with one CrO5 square pyramid, edges with two equivalent ZnO5 trigonal bipyramids, and a faceface with one CrO5 square pyramid. There are a spread of Zn–O bond distances ranging from 2.07–2.23 Å. In the second Zn2+ site, Zn2+ is bonded to five O2- atoms to form ZnO5 trigonal bipyramids that share corners with six CrO5 square pyramids, an edgeedge with one CrO5 square pyramid, edges with two equivalent ZnO5 trigonal bipyramids, and a faceface with one CrO5 square pyramid. There are a spread of Zn–O bond distances ranging from 2.07–2.24 Å. In the third Zn2+ site, Zn2+ is bonded in a water-like geometry to two O2- atoms. There are one shorter (2.06 Å) and one longer (2.08 Å) Zn–O bond lengths. In the fourth Zn2+ site, Zn2+ is bonded in a water-like geometry to two O2- atoms. There are one shorter (2.07 Å) and one longer (2.08 Å) Zn–O bond lengths. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to three Cr2+ and one Zn2+ atom to form distorted OZnCr3 tetrahedra that share corners with two equivalent OZnCr3 tetrahedra and edges with two equivalent OZn3Cr2 trigonal bipyramids. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to three Cr2+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to three Cr2+ atoms. In the fourth O2- site, O2- is bonded to three Cr2+ and one Zn2+ atom to form distorted OZnCr3 tetrahedra that share corners with two equivalent OZnCr3 tetrahedra and edges with two equivalent OZn3Cr2 trigonal bipyramids. In the fifth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Cr2+ and three Zn2+ atoms. In the sixth O2- site, O2- is bonded to two equivalent Cr2+ and three Zn2+ atoms to form distorted OZn3Cr2 trigonal bipyramids that share edges with two equivalent OZnCr3 tetrahedra and edges with two equivalent OZn3Cr2 trigonal bipyramids. In the seventh O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Cr2+ and three Zn2+ atoms. In the eighth O2- site, O2- is bonded to two equivalent Cr2+ and three Zn2+ atoms to form distorted OZn3Cr2 trigonal bipyramids that share edges with two equivalent OZnCr3 tetrahedra and edges with two equivalent OZn3Cr2 trigonal bipyramids.