Materials Data on Cr4CuNiSe8 by Materials Project
Cr4NiCuSe8 is Spinel-derived structured and crystallizes in the cubic F-43m space group. The structure is three-dimensional. Cr3+ is bonded to six Se2- atoms to form CrSe6 octahedra that share corners with three equivalent NiSe4 tetrahedra, corners with three equivalent CuSe4 tetrahedra, and edges with six equivalent CrSe6 octahedra. All Cr–Se bond lengths are 2.52 Å. Ni2+ is bonded to four equivalent Se2- atoms to form NiSe4 tetrahedra that share corners with twelve equivalent CrSe6 octahedra. The corner-sharing octahedral tilt angles are 56°. All Ni–Se bond lengths are 2.32 Å. Cu2+ is bonded to four equivalent Se2- atoms to form CuSe4 tetrahedra that share corners with twelve equivalent CrSe6 octahedra. The corner-sharing octahedral tilt angles are 58°. All Cu–Se bond lengths are 2.38 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to three equivalent Cr3+ and one Cu2+ atom to form a mixture of distorted edge and corner-sharing SeCr3Cu trigonal pyramids. In the second Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent Cr3+ and one Ni2+ atom.