DOI: 10.17188/1751817
title: Materials Data on Co4Cu3(NiSe6)2 by Materials Project

description: Co4Cu3(NiSe6)2 is Spinel-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Co+3.50+ sites. In the first Co+3.50+ site, Co+3.50+ is bonded to six Se2- atoms to form CoSe6 octahedra that share corners with six CuSe4 tetrahedra, edges with two NiSe6 octahedra, and edges with four equivalent CoSe6 octahedra. There are four shorter (2.39 Å) and two longer (2.40 Å) Co–Se bond lengths. In the second Co+3.50+ site, Co+3.50+ is bonded to six Se2- atoms to form CoSe6 octahedra that share corners with six CuSe4 tetrahedra, edges with two equivalent CoSe6 octahedra, and edges with four NiSe6 octahedra. All Co–Se bond lengths are 2.39 Å. In the third Co+3.50+ site, Co+3.50+ is bonded to six Se2- atoms to form CoSe6 octahedra that share corners with six CuSe4 tetrahedra, edges with two NiSe6 octahedra, and edges with four CoSe6 octahedra. There are four shorter (2.39 Å) and two longer (2.40 Å) Co–Se bond lengths. There are three inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded to six Se2- atoms to form NiSe6 octahedra that share corners with six CuSe4 tetrahedra, an edgeedge with one NiSe6 octahedra, and edges with five CoSe6 octahedra. There are two shorter (2.41 Å) and four longer (2.42 Å) Ni–Se bond lengths. In the second Ni2+ site, Ni2+ is bonded to six Se2- atoms to form NiSe6 octahedra that share corners with six equivalent CuSe4 tetrahedra and edges with six CoSe6 octahedra. All Ni–Se bond lengths are 2.42 Å. In the third Ni2+ site, Ni2+ is bonded to six Se2- atoms to form NiSe6 octahedra that share corners with six CuSe4 tetrahedra, edges with two equivalent NiSe6 octahedra, and edges with four equivalent CoSe6 octahedra. There are four shorter (2.41 Å) and two longer (2.42 Å) Ni–Se bond lengths. There are three inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with three equivalent NiSe6 octahedra and corners with nine CoSe6 octahedra. The corner-sharing octahedra tilt angles range from 59–60°. All Cu–Se bond lengths are 2.41 Å. In the second Cu2+ site, Cu2+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with five NiSe6 octahedra and corners with seven CoSe6 octahedra. The corner-sharing octahedra tilt angles range from 58–60°. All Cu–Se bond lengths are 2.41 Å. In the third Cu2+ site, Cu2+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with four NiSe6 octahedra and corners with eight CoSe6 octahedra. The corner-sharing octahedra tilt angles range from 59–60°. There are three shorter (2.41 Å) and one longer (2.42 Å) Cu–Se bond lengths. There are nine inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to two equivalent Co+3.50+, one Ni2+, and one Cu2+ atom to form a mixture of distorted edge and corner-sharing SeCo2CuNi trigonal pyramids. In the second Se2- site, Se2- is bonded to two equivalent Co+3.50+, one Ni2+, and one Cu2+ atom to form a mixture of distorted edge and corner-sharing SeCo2CuNi trigonal pyramids. In the third Se2- site, Se2- is bonded to two equivalent Co+3.50+, one Ni2+, and one Cu2+ atom to form distorted SeCo2CuNi trigonal pyramids that share corners with twelve SeCo2CuNi trigonal pyramids and edges with three SeCo3Cu trigonal pyramids. In the fourth Se2- site, Se2- is bonded to three Co+3.50+ and one Cu2+ atom to form a mixture of distorted edge and corner-sharing SeCo3Cu trigonal pyramids. In the fifth Se2- site, Se2- is bonded to two equivalent Co+3.50+, one Ni2+, and one Cu2+ atom to form distorted SeCo2CuNi trigonal pyramids that share corners with twelve SeCo2CuNi trigonal pyramids and edges with three SeCoCuNi2 trigonal pyramids. In the sixth Se2- site, Se2- is bonded to three Co+3.50+ and one Cu2+ atom to form a mixture of distorted edge and corner-sharing SeCo3Cu trigonal pyramids. In the seventh Se2- site, Se2- is bonded to two Co+3.50+, one Ni2+, and one Cu2+ atom to form a mixture of distorted edge and corner-sharing SeCo2CuNi trigonal pyramids. In the eighth Se2- site, Se2- is bonded to one Co+3.50+, two Ni2+, and one Cu2+ atom to form a mixture of distorted edge and corner-sharing SeCoCuNi2 trigonal pyramids. In the ninth Se2- site, Se2- is bonded to two Co+3.50+, one Ni2+, and one Cu2+ atom to form distorted SeCo2CuNi trigonal pyramids that share corners with twelve SeCo2CuNi trigonal pyramids and edges with three SeCo3Cu trigonal pyramids.