Materials Data on Cr8CoCu3Se16 by Materials Project

Cr8CoCu3Se16 is Spinel-derived structured and crystallizes in the tetragonal P-4m2 space group. The structure is three-dimensional. there are two inequivalent Cr3+ sites. In the first Cr3+ site, Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share a cornercorner with one CoSe4 tetrahedra, corners with five CuSe4 tetrahedra, and edges with six CrSe6 octahedra. There are a spread of Cr–Se bond distances ranging from 2.51–2.56 Å. In the second Cr3+ site, Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with two equivalent CoSe4 tetrahedra, corners with four CuSe4 tetrahedra, and edges with six CrSe6 octahedra. There are a spread of Cr–Se bond distances ranging from 2.51–2.56 Å. Co2+ is bonded to four equivalent Se2- atoms to form CoSe4 tetrahedra that share corners with twelve CrSe6 octahedra. The corner-sharing octahedral tilt angles are 57°. All Co–Se bond lengths are 2.37 Å. There are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded to four equivalent Se2- atoms to form CuSe4 tetrahedra that share corners with twelve CrSe6 octahedra. The corner-sharing octahedral tilt angles are 58°. All Cu–Se bond lengths are 2.40 Å. In the second Cu2+ site, Cu2+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with twelve CrSe6 octahedra. The corner-sharing octahedral tilt angles are 57°. All Cu–Se bond lengths are 2.40 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three Cr3+ and one Co2+ atom. In the second Se2- site, Se2- is bonded to three Cr3+ and one Cu2+ atom to form a mixture of distorted corner and edge-sharing SeCr3Cu trigonal pyramids. In the third Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent Cr3+ and one Cu2+ atom. In the fourth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent Cr3+ and one Cu2+ atom.