Materials Data on Cr6Co2CuSe12 by Materials Project
Cr6Co2CuSe12 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Cr3+ sites. In the first Cr3+ site, Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with two equivalent CuSe6 octahedra, corners with four equivalent CoSe6 octahedra, edges with six CrSe6 octahedra, and a faceface with one CoSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–53°. There are a spread of Cr–Se bond distances ranging from 2.48–2.62 Å. In the second Cr3+ site, Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with six equivalent CoSe6 octahedra, edges with six CrSe6 octahedra, and a faceface with one CoSe6 octahedra. The corner-sharing octahedra tilt angles range from 48–52°. There are a spread of Cr–Se bond distances ranging from 2.50–2.62 Å. In the third Cr3+ site, Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with two equivalent CoSe6 octahedra, corners with four equivalent CuSe6 octahedra, edges with six CrSe6 octahedra, and a faceface with one CuSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–53°. There are a spread of Cr–Se bond distances ranging from 2.51–2.56 Å. Co2+ is bonded to six Se2- atoms to form CoSe6 octahedra that share corners with twelve CrSe6 octahedra, edges with two equivalent CoSe6 octahedra, and faces with two CrSe6 octahedra. The corner-sharing octahedra tilt angles range from 48–53°. There are a spread of Co–Se bond distances ranging from 2.47–2.52 Å. Cu2+ is bonded to six Se2- atoms to form CuSe6 octahedra that share corners with twelve CrSe6 octahedra, edges with two equivalent CuSe6 octahedra, and faces with two equivalent CrSe6 octahedra. The corner-sharing octahedra tilt angles range from 49–53°. There are two shorter (2.54 Å) and four longer (2.59 Å) Cu–Se bond lengths. There are six inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-coordinate geometry to three Cr3+ and two equivalent Co2+ atoms. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to three Cr3+ and two equivalent Co2+ atoms. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to three equivalent Cr3+ and two equivalent Cu2+ atoms. In the fourth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three Cr3+ and one Cu2+ atom. In the fifth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to three equivalent Cr3+ and one Co2+ atom. In the sixth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to three Cr3+ and one Co2+ atom.