Materials Data on MnFeNiO4 by Materials Project

NiFeMnO4 is Spinel-derived structured and crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six equivalent FeO4 tetrahedra, edges with two equivalent MnO6 octahedra, and edges with four equivalent NiO6 octahedra. There are two shorter (1.94 Å) and four longer (2.12 Å) Mn–O bond lengths. Fe3+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with six equivalent MnO6 octahedra and corners with six equivalent NiO6 octahedra. The corner-sharing octahedra tilt angles range from 55–58°. There is two shorter (1.91 Å) and two longer (1.94 Å) Fe–O bond length. Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent FeO4 tetrahedra, edges with two equivalent NiO6 octahedra, and edges with four equivalent MnO6 octahedra. There are two shorter (2.07 Å) and four longer (2.11 Å) Ni–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to two equivalent Mn3+, one Fe3+, and one Ni2+ atom. In the second O2- site, O2- is bonded to one Mn3+, one Fe3+, and two equivalent Ni2+ atoms to form a mixture of distorted edge and corner-sharing OMnFeNi2 trigonal pyramids.