MgCo3NiO8 is beta indium sulfide-derived structured and crystallizes in the trigonal R-3m space group. Mg(1) is bonded to six equivalent O(1) atoms to form MgO6 octahedra that share corners with six equivalent Ni(1)O6 octahedra and edges with six equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles are 14°. Co(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CoO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with four equivalent Co(1)O6 octahedra. Ni(1) is bonded to six equivalent O(1) atoms to form distorted NiO6 octahedra that share corners with six equivalent Mg(1)O6 octahedra and edges with six equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles are 14°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a see-saw-like geometry to one Mg(1), two equivalent Co(1), and one Ni(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Co(1) atoms.
MgCo3NiO8 is beta indium sulfide-derived structured and crystallizes in the trigonal R-3m space group. Mg(1) is bonded to six equivalent O(1) atoms to form MgO6 octahedra that share corners with six equivalent Ni(1)O6 octahedra and edges with six equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles are 14°. All Mg(1)-O(1) bond lengths are 2.06 Å. Co(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CoO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with four equivalent Co(1)O6 octahedra. Both Co(1)-O(2) bond lengths are 1.92 Å. All Co(1)-O(1) bond lengths are 1.89 Å. Ni(1) is bonded to six equivalent O(1) atoms to form distorted NiO6 octahedra that share corners with six equivalent Mg(1)O6 octahedra and edges with six equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles are 14°. All Ni(1)-O(1) bond lengths are 2.10 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a see-saw-like geometry to one Mg(1), two equivalent Co(1), and one Ni(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Co(1) atoms.