Materials Data on Mg3MnNi3O8 by Materials Project
Mg3MnNi3O8 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six equivalent NiO6 octahedra, edges with two equivalent MnO6 octahedra, edges with four equivalent MgO6 octahedra, and edges with four equivalent NiO6 octahedra. The corner-sharing octahedra tilt angles range from 1–9°. There are two shorter (2.10 Å) and four longer (2.12 Å) Mg–O bond lengths. Mn2+ is bonded to six equivalent O2- atoms to form MnO6 octahedra that share edges with six equivalent MgO6 octahedra and edges with six equivalent NiO6 octahedra. All Mn–O bond lengths are 1.94 Å. Ni+2.67+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent MgO6 octahedra, edges with two equivalent MnO6 octahedra, edges with four equivalent MgO6 octahedra, and edges with four equivalent NiO6 octahedra. The corner-sharing octahedra tilt angles range from 1–9°. All Ni–O bond lengths are 2.12 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to three equivalent Mg2+ and three equivalent Ni+2.67+ atoms to form OMg3Ni3 octahedra that share corners with six equivalent OMg3Ni3 octahedra and edges with twelve equivalent OMg2MnNi2 square pyramids. The corner-sharing octahedral tilt angles are 0°. In the second O2- site, O2- is bonded to two equivalent Mg2+, one Mn2+, and two equivalent Ni+2.67+ atoms to form OMg2MnNi2 square pyramids that share corners with nine equivalent OMg2MnNi2 square pyramids, edges with four equivalent OMg3Ni3 octahedra, and edges with four equivalent OMg2MnNi2 square pyramids.