Materials Data on ZnFe4NiO8 by Materials Project

Fe4NiZnO8 is Spinel-derived structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three equivalent FeO4 tetrahedra, corners with three equivalent ZnO4 tetrahedra, edges with two equivalent NiO6 octahedra, and edges with four equivalent FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.01–2.09 Å. In the second Fe3+ site, Fe3+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with three equivalent NiO6 octahedra and corners with nine equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 57–59°. There is three shorter (1.93 Å) and one longer (1.94 Å) Fe–O bond length. Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with three equivalent FeO4 tetrahedra, corners with three equivalent ZnO4 tetrahedra, and edges with six equivalent FeO6 octahedra. There are three shorter (2.06 Å) and three longer (2.12 Å) Ni–O bond lengths. Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share corners with three equivalent NiO6 octahedra and corners with nine equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 57–59°. There is three shorter (1.98 Å) and one longer (2.00 Å) Zn–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent Fe3+ and one Zn2+ atom. In the second O2- site, O2- is bonded to two equivalent Fe3+, one Ni2+, and one Zn2+ atom to form a mixture of distorted edge and corner-sharing OZnFe2Ni trigonal pyramids. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Fe3+ atoms. In the fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Fe3+ and one Ni2+ atom.