DOI: 10.17188/1676101
title: Materials Data on Mg6CoNiO8 by Materials Project

description: Mg6CoNiO8 is alpha Po-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are three inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with four equivalent CoO6 octahedra, and edges with eight equivalent MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.12 Å) and two longer (2.13 Å) Mg–O bond lengths. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with four equivalent NiO6 octahedra, and edges with eight equivalent MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.12 Å) and two longer (2.14 Å) Mg–O bond lengths. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six equivalent MgO6 octahedra, edges with two equivalent CoO6 octahedra, edges with two equivalent NiO6 octahedra, and edges with eight MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Mg–O bond distances ranging from 2.12–2.14 Å. Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with two equivalent NiO6 octahedra, corners with four equivalent CoO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.12 Å) and two longer (2.16 Å) Co–O bond lengths. Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with two equivalent CoO6 octahedra, corners with four equivalent NiO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.11 Å) and four longer (2.12 Å) Ni–O bond lengths. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Mg2+, one Co2+, and one Ni2+ atom to form OMg4CoNi octahedra that share corners with six equivalent OMg4CoNi octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the second O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six equivalent OMg6 octahedra and edges with twelve OMg4CoNi octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the third O2- site, O2- is bonded to four Mg2+ and two equivalent Co2+ atoms to form OMg4Co2 octahedra that share corners with six OMg4Co2 octahedra and edges with twelve OMg4CoNi octahedra. The corner-sharing octahedral tilt angles are 0°. In the fourth O2- site, O2- is bonded to four Mg2+ and two equivalent Ni2+ atoms to form OMg4Ni2 octahedra that share corners with six OMg4Co2 octahedra and edges with twelve OMg4CoNi octahedra. The corner-sharing octahedral tilt angles are 0°. In the fifth O2- site, O2- is bonded to four Mg2+ and two equivalent Co2+ atoms to form OMg4Co2 octahedra that share corners with six OMg4Co2 octahedra and edges with twelve OMg4CoNi octahedra. The corner-sharing octahedral tilt angles are 0°. Both O–Mg bond lengths are 2.14 Å. In the sixth O2- site, O2- is bonded to four Mg2+ and two equivalent Ni2+ atoms to form OMg4Ni2 octahedra that share corners with six OMg4Co2 octahedra and edges with twelve OMg4CoNi octahedra. The corner-sharing octahedral tilt angles are 0°. Both O–Mg bond lengths are 2.13 Å.