MgCo7O12 is Corundum-derived structured and crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(10), one O(2), one O(5), one O(6), and one O(9) atom to form MgO6 octahedra that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra,  an edgeedge with one Co(2)O6 octahedra,  an edgeedge with one Co(4)O6 octahedra, edges with three equivalent Co(3)O6 octahedra, and edges with three equivalent Co(6)O6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are seven inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(11), one O(12), one O(3), one O(4), one O(7), and one O(8) atom to form a mixture of corner and edge-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles range from 17-18°. In the second Co site, Co(2) is bonded to one O(1), one O(12), one O(4), one O(5), one O(8), and one O(9) atom to form distorted CoO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(3)O6 octahedra,  a cornercorner with one Co(5)O6 octahedra,  a cornercorner with one Co(6)O6 octahedra,  a cornercorner with one Co(7)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Co(1)O6 octahedra,  an edgeedge with one Co(3)O6 octahedra,  an edgeedge with one Co(5)O6 octahedra,  an edgeedge with one Co(6)O6 octahedra, and  an edgeedge with one Co(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-17°. In the third Co site, Co(3) is bonded to one O(1), one O(10), one O(2), one O(5), one O(6), and one O(9) atom to form CoO6 octahedra that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra,  an edgeedge with one Co(2)O6 octahedra,  an edgeedge with one Co(4)O6 octahedra, edges with three equivalent Mg(1)O6 octahedra, and edges with three equivalent Co(6)O6 octahedra. The corner-sharing octahedral tilt angles are 9°. In the fourth Co site, Co(4) is bonded to one O(10), one O(11), one O(2), one O(3), one O(6), and one O(7) atom to form distorted CoO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(3)O6 octahedra,  a cornercorner with one Co(5)O6 octahedra,  a cornercorner with one Co(6)O6 octahedra,  a cornercorner with one Co(7)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Co(1)O6 octahedra,  an edgeedge with one Co(3)O6 octahedra,  an edgeedge with one Co(5)O6 octahedra,  an edgeedge with one Co(6)O6 octahedra, and  an edgeedge with one Co(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-18°. In the fifth Co site, Co(5) is bonded to one O(11), one O(12), one O(3), one O(4), one O(7), and one O(8) atom to form a mixture of corner and edge-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles range from 12-13°. In the sixth Co site, Co(6) is bonded to one O(1), one O(10), one O(2), one O(5), one O(6), and one O(9) atom to form CoO6 octahedra that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra,  an edgeedge with one Co(2)O6 octahedra,  an edgeedge with one Co(4)O6 octahedra, edges with three equivalent Mg(1)O6 octahedra, and edges with three equivalent Co(3)O6 octahedra. The corner-sharing octahedral tilt angles are 9°. In the seventh Co site, Co(7) is bonded to one O(11), one O(12), one O(3), one O(4), one O(7), and one O(8) atom to form a mixture of corner and edge-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles are 16°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(2), one Co(3), and one Co(6) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(3), one Co(4), and one Co(6) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Co(1), one Co(4), one Co(5), and one Co(7) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Co(1), one Co(2), one Co(5), and one Co(7) atom. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(2), one Co(3), and one Co(6) atom. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(3), one Co(4), and one Co(6) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Co(1), one Co(4), one Co(5), and one Co(7) atom. In the eighth O site, O(8) is bonded in a distorted rectangular see-saw-like geometry to one Co(1), one Co(2), one Co(5), and one Co(7) atom. In the ninth O site, O(9) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(2), one Co(3), and one Co(6) atom. In the tenth O site, O(10) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(3), one Co(4), and one Co(6) atom. In the eleventh O site, O(11) is bonded in a distorted see-saw-like geometry to one Co(1), one Co(4), one Co(5), and one Co(7) atom. In the twelfth O site, O(12) is bonded in a distorted see-saw-like geometry to one Co(1), one Co(2), one Co(5), and one Co(7) atom.
MgCo7O12 is Corundum-derived structured and crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(10), one O(2), one O(5), one O(6), and one O(9) atom to form MgO6 octahedra that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra,  an edgeedge with one Co(2)O6 octahedra,  an edgeedge with one Co(4)O6 octahedra, edges with three equivalent Co(3)O6 octahedra, and edges with three equivalent Co(6)O6 octahedra. The corner-sharing octahedral tilt angles are 5°. The Mg(1)-O(1) bond length is 2.03 Å. The Mg(1)-O(10) bond length is 2.15 Å. The Mg(1)-O(2) bond length is 2.03 Å. The Mg(1)-O(5) bond length is 2.01 Å. The Mg(1)-O(6) bond length is 2.02 Å. The Mg(1)-O(9) bond length is 2.14 Å. There are seven inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(11), one O(12), one O(3), one O(4), one O(7), and one O(8) atom to form a mixture of corner and edge-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles range from 17-18°. The Co(1)-O(11) bond length is 2.05 Å. The Co(1)-O(12) bond length is 2.06 Å. The Co(1)-O(3) bond length is 2.03 Å. The Co(1)-O(4) bond length is 2.03 Å. The Co(1)-O(7) bond length is 1.93 Å. The Co(1)-O(8) bond length is 1.94 Å. In the second Co site, Co(2) is bonded to one O(1), one O(12), one O(4), one O(5), one O(8), and one O(9) atom to form distorted CoO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(3)O6 octahedra,  a cornercorner with one Co(5)O6 octahedra,  a cornercorner with one Co(6)O6 octahedra,  a cornercorner with one Co(7)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Co(1)O6 octahedra,  an edgeedge with one Co(3)O6 octahedra,  an edgeedge with one Co(5)O6 octahedra,  an edgeedge with one Co(6)O6 octahedra, and  an edgeedge with one Co(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-17°. The Co(2)-O(1) bond length is 1.99 Å. The Co(2)-O(12) bond length is 2.18 Å. The Co(2)-O(4) bond length is 1.99 Å. The Co(2)-O(5) bond length is 2.02 Å. The Co(2)-O(8) bond length is 2.37 Å. The Co(2)-O(9) bond length is 1.89 Å. In the third Co site, Co(3) is bonded to one O(1), one O(10), one O(2), one O(5), one O(6), and one O(9) atom to form CoO6 octahedra that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra,  an edgeedge with one Co(2)O6 octahedra,  an edgeedge with one Co(4)O6 octahedra, edges with three equivalent Mg(1)O6 octahedra, and edges with three equivalent Co(6)O6 octahedra. The corner-sharing octahedral tilt angles are 9°. The Co(3)-O(1) bond length is 1.92 Å. The Co(3)-O(10) bond length is 2.07 Å. The Co(3)-O(2) bond length is 1.92 Å. The Co(3)-O(5) bond length is 1.88 Å. The Co(3)-O(6) bond length is 1.88 Å. The Co(3)-O(9) bond length is 2.07 Å. In the fourth Co site, Co(4) is bonded to one O(10), one O(11), one O(2), one O(3), one O(6), and one O(7) atom to form distorted CoO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(3)O6 octahedra,  a cornercorner with one Co(5)O6 octahedra,  a cornercorner with one Co(6)O6 octahedra,  a cornercorner with one Co(7)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Co(1)O6 octahedra,  an edgeedge with one Co(3)O6 octahedra,  an edgeedge with one Co(5)O6 octahedra,  an edgeedge with one Co(6)O6 octahedra, and  an edgeedge with one Co(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-18°. The Co(4)-O(10) bond length is 1.89 Å. The Co(4)-O(11) bond length is 2.17 Å. The Co(4)-O(2) bond length is 1.98 Å. The Co(4)-O(3) bond length is 1.99 Å. The Co(4)-O(6) bond length is 2.01 Å. The Co(4)-O(7) bond length is 2.42 Å. In the fifth Co site, Co(5) is bonded to one O(11), one O(12), one O(3), one O(4), one O(7), and one O(8) atom to form a mixture of corner and edge-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles range from 12-13°. The Co(5)-O(11) bond length is 1.90 Å. The Co(5)-O(12) bond length is 1.89 Å. The Co(5)-O(3) bond length is 1.86 Å. The Co(5)-O(4) bond length is 1.86 Å. The Co(5)-O(7) bond length is 1.96 Å. The Co(5)-O(8) bond length is 1.96 Å. In the sixth Co site, Co(6) is bonded to one O(1), one O(10), one O(2), one O(5), one O(6), and one O(9) atom to form CoO6 octahedra that share  a cornercorner with one Co(2)O6 octahedra,  a cornercorner with one Co(4)O6 octahedra,  an edgeedge with one Co(2)O6 octahedra,  an edgeedge with one Co(4)O6 octahedra, edges with three equivalent Mg(1)O6 octahedra, and edges with three equivalent Co(3)O6 octahedra. The corner-sharing octahedral tilt angles are 9°. The Co(6)-O(1) bond length is 1.92 Å. The Co(6)-O(10) bond length is 1.91 Å. The Co(6)-O(2) bond length is 1.92 Å. The Co(6)-O(5) bond length is 2.01 Å. The Co(6)-O(6) bond length is 2.01 Å. The Co(6)-O(9) bond length is 1.91 Å. In the seventh Co site, Co(7) is bonded to one O(11), one O(12), one O(3), one O(4), one O(7), and one O(8) atom to form a mixture of corner and edge-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles are 16°. The Co(7)-O(11) bond length is 1.91 Å. The Co(7)-O(12) bond length is 1.91 Å. The Co(7)-O(3) bond length is 2.19 Å. The Co(7)-O(4) bond length is 2.19 Å. The Co(7)-O(7) bond length is 1.89 Å. The Co(7)-O(8) bond length is 1.89 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(2), one Co(3), and one Co(6) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(3), one Co(4), and one Co(6) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Co(1), one Co(4), one Co(5), and one Co(7) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Co(1), one Co(2), one Co(5), and one Co(7) atom. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(2), one Co(3), and one Co(6) atom. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(3), one Co(4), and one Co(6) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Co(1), one Co(4), one Co(5), and one Co(7) atom. In the eighth O site, O(8) is bonded in a distorted rectangular see-saw-like geometry to one Co(1), one Co(2), one Co(5), and one Co(7) atom. In the ninth O site, O(9) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(2), one Co(3), and one Co(6) atom. In the tenth O site, O(10) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(3), one Co(4), and one Co(6) atom. In the eleventh O site, O(11) is bonded in a distorted see-saw-like geometry to one Co(1), one Co(4), one Co(5), and one Co(7) atom. In the twelfth O site, O(12) is bonded in a distorted see-saw-like geometry to one Co(1), one Co(2), one Co(5), and one Co(7) atom.