MgMn2CoO6 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(4), two equivalent O(3), and two equivalent O(5) atoms to form MgO6 octahedra that share  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Co(1)O6 octahedra, corners with four equivalent Mn(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-22°. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(6) atoms to form MnO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles are 19°. In the second Mn site, Mn(2) is bonded to one O(2), one O(6), two equivalent O(3), and two equivalent O(5) atoms to form MnO6 octahedra that share corners with four equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-12°. Co(1) is bonded to one O(1), one O(5), two equivalent O(2), and two equivalent O(4) atoms to form CoO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles are 22°. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), two equivalent Mn(1), and one Co(1) atom to form OMgMn2Co trigonal pyramids that share corners with three equivalent O(5)Mg2Mn2Co square pyramids, corners with two equivalent O(1)MgMn2Co trigonal pyramids, and edges with two equivalent O(3)Mg2Mn3 square pyramids. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Mn(2) and two equivalent Co(1) atoms. In the third O site, O(3) is bonded to two equivalent Mg(1), one Mn(1), and two equivalent Mn(2) atoms to form OMg2Mn3 square pyramids that share corners with four equivalent O(5)Mg2Mn2Co square pyramids, edges with two equivalent O(5)Mg2Mn2Co square pyramids, edges with two equivalent O(3)Mg2Mn3 square pyramids, and edges with two equivalent O(1)MgMn2Co trigonal pyramids. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mn(1), and two equivalent Co(1) atoms. In the fifth O site, O(5) is bonded to two equivalent Mg(1), two equivalent Mn(2), and one Co(1) atom to form OMg2Mn2Co square pyramids that share corners with four equivalent O(3)Mg2Mn3 square pyramids, corners with three equivalent O(1)MgMn2Co trigonal pyramids, edges with two equivalent O(5)Mg2Mn2Co square pyramids, and edges with two equivalent O(3)Mg2Mn3 square pyramids. In the sixth O site, O(6) is bonded in a trigonal non-coplanar geometry to one Mn(2) and two equivalent Mn(1) atoms.
MgMn2CoO6 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(4), two equivalent O(3), and two equivalent O(5) atoms to form MgO6 octahedra that share  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Co(1)O6 octahedra, corners with four equivalent Mn(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-22°. The Mg(1)-O(1) bond length is 2.13 Å. The Mg(1)-O(4) bond length is 2.07 Å. There is one shorter (2.14 Å) and one longer (2.17 Å) Mg(1)-O(3) bond length. Both Mg(1)-O(5) bond lengths are 2.11 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(6) atoms to form MnO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles are 19°. The Mn(1)-O(3) bond length is 1.97 Å. The Mn(1)-O(4) bond length is 1.92 Å. There is one shorter (1.96 Å) and one longer (1.99 Å) Mn(1)-O(1) bond length. There is one shorter (1.94 Å) and one longer (1.96 Å) Mn(1)-O(6) bond length. In the second Mn site, Mn(2) is bonded to one O(2), one O(6), two equivalent O(3), and two equivalent O(5) atoms to form MnO6 octahedra that share corners with four equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-12°. The Mn(2)-O(2) bond length is 1.94 Å. The Mn(2)-O(6) bond length is 1.98 Å. There is one shorter (2.01 Å) and one longer (2.32 Å) Mn(2)-O(3) bond length. There is one shorter (1.97 Å) and one longer (2.28 Å) Mn(2)-O(5) bond length. Co(1) is bonded to one O(1), one O(5), two equivalent O(2), and two equivalent O(4) atoms to form CoO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles are 22°. The Co(1)-O(1) bond length is 2.02 Å. The Co(1)-O(5) bond length is 2.12 Å. There is one shorter (1.85 Å) and one longer (2.07 Å) Co(1)-O(2) bond length. There is one shorter (2.05 Å) and one longer (2.12 Å) Co(1)-O(4) bond length. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), two equivalent Mn(1), and one Co(1) atom to form OMgMn2Co trigonal pyramids that share corners with three equivalent O(5)Mg2Mn2Co square pyramids, corners with two equivalent O(1)MgMn2Co trigonal pyramids, and edges with two equivalent O(3)Mg2Mn3 square pyramids. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Mn(2) and two equivalent Co(1) atoms. In the third O site, O(3) is bonded to two equivalent Mg(1), one Mn(1), and two equivalent Mn(2) atoms to form OMg2Mn3 square pyramids that share corners with four equivalent O(5)Mg2Mn2Co square pyramids, edges with two equivalent O(5)Mg2Mn2Co square pyramids, edges with two equivalent O(3)Mg2Mn3 square pyramids, and edges with two equivalent O(1)MgMn2Co trigonal pyramids. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mn(1), and two equivalent Co(1) atoms. In the fifth O site, O(5) is bonded to two equivalent Mg(1), two equivalent Mn(2), and one Co(1) atom to form OMg2Mn2Co square pyramids that share corners with four equivalent O(3)Mg2Mn3 square pyramids, corners with three equivalent O(1)MgMn2Co trigonal pyramids, edges with two equivalent O(5)Mg2Mn2Co square pyramids, and edges with two equivalent O(3)Mg2Mn3 square pyramids. In the sixth O site, O(6) is bonded in a trigonal non-coplanar geometry to one Mn(2) and two equivalent Mn(1) atoms.