Materials Data on Fe4CuNiO8 by Materials Project

Fe4NiCuO8 is Spinel-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with three equivalent NiO6 octahedra, corners with three equivalent CuO6 octahedra, and corners with six equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 54–60°. There are a spread of Fe–O bond distances ranging from 1.91–1.96 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six equivalent FeO4 tetrahedra, edges with two equivalent FeO6 octahedra, edges with two equivalent NiO6 octahedra, and edges with two equivalent CuO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.03–2.06 Å. Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent FeO4 tetrahedra, edges with two equivalent CuO6 octahedra, and edges with four equivalent FeO6 octahedra. There are four shorter (2.08 Å) and two longer (2.13 Å) Ni–O bond lengths. Cu2+ is bonded to six O2- atoms to form CuO6 octahedra that share corners with six equivalent FeO4 tetrahedra, edges with two equivalent NiO6 octahedra, and edges with four equivalent FeO6 octahedra. There are four shorter (2.00 Å) and two longer (2.27 Å) Cu–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Fe3+ and one Cu2+ atom. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Fe3+ and one Ni2+ atom. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Fe3+, one Ni2+, and one Cu2+ atom.