MgCo(NiO2)4 is Corundum-derived structured and crystallizes in the monoclinic Cm space group. Mg(1) is bonded in a distorted rectangular see-saw-like geometry to one O(4), one O(6), and two equivalent O(2) atoms. Co(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form CoO6 octahedra that share edges with two equivalent Ni(2)O6 octahedra and edges with four equivalent Ni(1)O6 octahedra. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form NiO6 octahedra that share edges with two equivalent Co(1)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with two equivalent Ni(2)O6 octahedra. In the second Ni site, Ni(2) is bonded to one O(5), one O(6), two equivalent O(1), and two equivalent O(2) atoms to form NiO6 octahedra that share edges with two equivalent Co(1)O6 octahedra and edges with four equivalent Ni(1)O6 octahedra. In the third Ni site, Ni(3) is bonded in a distorted rectangular see-saw-like geometry to one O(3), one O(5), and two equivalent O(1) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Co(1), one Ni(1), one Ni(2), and one Ni(3) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(1), one Ni(1), and one Ni(2) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Co(1), one Ni(3), and two equivalent Ni(1) atoms. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(1), and two equivalent Ni(1) atoms. In the fifth O site, O(5) is bonded in a see-saw-like geometry to one Ni(2), one Ni(3), and two equivalent Ni(1) atoms. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Ni(2), and two equivalent Ni(1) atoms.
MgCo(NiO2)4 is Corundum-derived structured and crystallizes in the monoclinic Cm space group. Mg(1) is bonded in a distorted rectangular see-saw-like geometry to one O(4), one O(6), and two equivalent O(2) atoms. The Mg(1)-O(4) bond length is 1.91 Å. The Mg(1)-O(6) bond length is 1.98 Å. Both Mg(1)-O(2) bond lengths are 2.05 Å. Co(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form CoO6 octahedra that share edges with two equivalent Ni(2)O6 octahedra and edges with four equivalent Ni(1)O6 octahedra. The Co(1)-O(3) bond length is 1.92 Å. The Co(1)-O(4) bond length is 1.90 Å. Both Co(1)-O(1) bond lengths are 1.89 Å. Both Co(1)-O(2) bond lengths are 1.90 Å. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form NiO6 octahedra that share edges with two equivalent Co(1)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with two equivalent Ni(2)O6 octahedra. The Ni(1)-O(1) bond length is 1.96 Å. The Ni(1)-O(2) bond length is 1.96 Å. The Ni(1)-O(3) bond length is 2.10 Å. The Ni(1)-O(4) bond length is 2.08 Å. The Ni(1)-O(5) bond length is 1.89 Å. The Ni(1)-O(6) bond length is 1.90 Å. In the second Ni site, Ni(2) is bonded to one O(5), one O(6), two equivalent O(1), and two equivalent O(2) atoms to form NiO6 octahedra that share edges with two equivalent Co(1)O6 octahedra and edges with four equivalent Ni(1)O6 octahedra. The Ni(2)-O(5) bond length is 2.06 Å. The Ni(2)-O(6) bond length is 2.03 Å. Both Ni(2)-O(1) bond lengths are 2.13 Å. Both Ni(2)-O(2) bond lengths are 2.11 Å. In the third Ni site, Ni(3) is bonded in a distorted rectangular see-saw-like geometry to one O(3), one O(5), and two equivalent O(1) atoms. The Ni(3)-O(3) bond length is 1.88 Å. The Ni(3)-O(5) bond length is 1.99 Å. Both Ni(3)-O(1) bond lengths are 2.05 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Co(1), one Ni(1), one Ni(2), and one Ni(3) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(1), one Ni(1), and one Ni(2) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Co(1), one Ni(3), and two equivalent Ni(1) atoms. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(1), and two equivalent Ni(1) atoms. In the fifth O site, O(5) is bonded in a see-saw-like geometry to one Ni(2), one Ni(3), and two equivalent Ni(1) atoms. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Ni(2), and two equivalent Ni(1) atoms.