MgCo6(OF)6 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(4), one O(6), one F(1), one F(3), and one F(5) atom to form MgO3F3 octahedra that share corners with two equivalent Co(2)O3F3 octahedra, corners with two equivalent Co(3)O3F3 octahedra, edges with two equivalent Co(4)O3F3 octahedra, edges with two equivalent Co(5)O3F3 octahedra, and faces with two equivalent Co(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 35-56°. There are six inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(1), one O(4), one O(6), one F(1), one F(3), and one F(5) atom to form distorted CoO3F3 octahedra that share corners with four equivalent Co(4)O3F3 octahedra, corners with four equivalent Co(5)O3F3 octahedra,  an edgeedge with one Co(2)O3F3 octahedra,  an edgeedge with one Co(3)O3F3 octahedra, and faces with two equivalent Mg(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 38-56°. In the second Co site, Co(2) is bonded to one O(2), one O(5), one O(6), one F(1), one F(2), and one F(6) atom to form CoO3F3 octahedra that share corners with two equivalent Mg(1)O3F3 octahedra, corners with four equivalent Co(4)O3F3 octahedra, corners with four equivalent Co(6)O3F3 octahedra,  an edgeedge with one Co(1)O3F3 octahedra, and  an edgeedge with one Co(3)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 42-61°. In the third Co site, Co(3) is bonded to one O(1), one O(2), one O(3), one F(4), one F(5), and one F(6) atom to form CoO3F3 octahedra that share corners with two equivalent Mg(1)O3F3 octahedra, corners with four equivalent Co(5)O3F3 octahedra, corners with four equivalent Co(6)O3F3 octahedra,  an edgeedge with one Co(1)O3F3 octahedra, and  an edgeedge with one Co(2)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 35-64°. In the fourth Co site, Co(4) is bonded to one O(4), one O(5), one O(6), one F(1), one F(2), and one F(3) atom to form distorted CoO3F3 octahedra that share corners with four equivalent Co(1)O3F3 octahedra, corners with four equivalent Co(2)O3F3 octahedra,  an edgeedge with one Co(5)O3F3 octahedra,  an edgeedge with one Co(6)O3F3 octahedra, and edges with two equivalent Mg(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 41-61°. In the fifth Co site, Co(5) is bonded to one O(1), one O(3), one O(4), one F(3), one F(4), and one F(5) atom to form CoO3F3 octahedra that share corners with four equivalent Co(1)O3F3 octahedra, corners with four equivalent Co(3)O3F3 octahedra,  an edgeedge with one Co(4)O3F3 octahedra,  an edgeedge with one Co(6)O3F3 octahedra, and edges with two equivalent Mg(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 38-64°. In the sixth Co site, Co(6) is bonded to one O(2), one O(3), one O(5), one F(2), one F(4), and one F(6) atom to form a mixture of distorted corner and edge-sharing CoO3F3 octahedra. The corner-sharing octahedral tilt angles range from 43-54°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Co(1), one Co(3), and one Co(5) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Co(2), one Co(3), and one Co(6) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Co(3), one Co(5), and one Co(6) atom. In the fourth O site, O(4) is bonded in a trigonal pyramidal geometry to one Mg(1), one Co(1), one Co(4), and one Co(5) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Co(2), one Co(4), and one Co(6) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Co(1), one Co(2), and one Co(4) atom. There are six inequivalent F sites. In the first F site, F(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(1), one Co(2), and one Co(4) atom. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Co(2), one Co(4), and one Co(6) atom. In the third F site, F(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Co(1), one Co(4), and one Co(5) atom. In the fourth F site, F(4) is bonded in a distorted T-shaped geometry to one Co(3), one Co(5), and one Co(6) atom. In the fifth F site, F(5) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Co(1), one Co(3), and one Co(5) atom. In the sixth F site, F(6) is bonded in a 3-coordinate geometry to one Co(2), one Co(3), and one Co(6) atom.
MgCo6(OF)6 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(4), one O(6), one F(1), one F(3), and one F(5) atom to form MgO3F3 octahedra that share corners with two equivalent Co(2)O3F3 octahedra, corners with two equivalent Co(3)O3F3 octahedra, edges with two equivalent Co(4)O3F3 octahedra, edges with two equivalent Co(5)O3F3 octahedra, and faces with two equivalent Co(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 35-56°. The Mg(1)-O(1) bond length is 2.10 Å. The Mg(1)-O(4) bond length is 1.98 Å. The Mg(1)-O(6) bond length is 2.11 Å. The Mg(1)-F(1) bond length is 2.01 Å. The Mg(1)-F(3) bond length is 1.89 Å. The Mg(1)-F(5) bond length is 2.03 Å. There are six inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(1), one O(4), one O(6), one F(1), one F(3), and one F(5) atom to form distorted CoO3F3 octahedra that share corners with four equivalent Co(4)O3F3 octahedra, corners with four equivalent Co(5)O3F3 octahedra,  an edgeedge with one Co(2)O3F3 octahedra,  an edgeedge with one Co(3)O3F3 octahedra, and faces with two equivalent Mg(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 38-56°. The Co(1)-O(1) bond length is 1.99 Å. The Co(1)-O(4) bond length is 1.98 Å. The Co(1)-O(6) bond length is 1.97 Å. The Co(1)-F(1) bond length is 2.17 Å. The Co(1)-F(3) bond length is 2.33 Å. The Co(1)-F(5) bond length is 2.07 Å. In the second Co site, Co(2) is bonded to one O(2), one O(5), one O(6), one F(1), one F(2), and one F(6) atom to form CoO3F3 octahedra that share corners with two equivalent Mg(1)O3F3 octahedra, corners with four equivalent Co(4)O3F3 octahedra, corners with four equivalent Co(6)O3F3 octahedra,  an edgeedge with one Co(1)O3F3 octahedra, and  an edgeedge with one Co(3)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 42-61°. The Co(2)-O(2) bond length is 2.00 Å. The Co(2)-O(5) bond length is 2.02 Å. The Co(2)-O(6) bond length is 2.02 Å. The Co(2)-F(1) bond length is 2.30 Å. The Co(2)-F(2) bond length is 2.29 Å. The Co(2)-F(6) bond length is 2.04 Å. In the third Co site, Co(3) is bonded to one O(1), one O(2), one O(3), one F(4), one F(5), and one F(6) atom to form CoO3F3 octahedra that share corners with two equivalent Mg(1)O3F3 octahedra, corners with four equivalent Co(5)O3F3 octahedra, corners with four equivalent Co(6)O3F3 octahedra,  an edgeedge with one Co(1)O3F3 octahedra, and  an edgeedge with one Co(2)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 35-64°. The Co(3)-O(1) bond length is 2.04 Å. The Co(3)-O(2) bond length is 2.01 Å. The Co(3)-O(3) bond length is 2.08 Å. The Co(3)-F(4) bond length is 2.23 Å. The Co(3)-F(5) bond length is 2.24 Å. The Co(3)-F(6) bond length is 2.08 Å. In the fourth Co site, Co(4) is bonded to one O(4), one O(5), one O(6), one F(1), one F(2), and one F(3) atom to form distorted CoO3F3 octahedra that share corners with four equivalent Co(1)O3F3 octahedra, corners with four equivalent Co(2)O3F3 octahedra,  an edgeedge with one Co(5)O3F3 octahedra,  an edgeedge with one Co(6)O3F3 octahedra, and edges with two equivalent Mg(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 41-61°. The Co(4)-O(4) bond length is 1.98 Å. The Co(4)-O(5) bond length is 1.87 Å. The Co(4)-O(6) bond length is 1.89 Å. The Co(4)-F(1) bond length is 2.23 Å. The Co(4)-F(2) bond length is 2.03 Å. The Co(4)-F(3) bond length is 2.25 Å. In the fifth Co site, Co(5) is bonded to one O(1), one O(3), one O(4), one F(3), one F(4), and one F(5) atom to form CoO3F3 octahedra that share corners with four equivalent Co(1)O3F3 octahedra, corners with four equivalent Co(3)O3F3 octahedra,  an edgeedge with one Co(4)O3F3 octahedra,  an edgeedge with one Co(6)O3F3 octahedra, and edges with two equivalent Mg(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 38-64°. The Co(5)-O(1) bond length is 1.91 Å. The Co(5)-O(3) bond length is 1.85 Å. The Co(5)-O(4) bond length is 1.91 Å. The Co(5)-F(3) bond length is 2.21 Å. The Co(5)-F(4) bond length is 2.06 Å. The Co(5)-F(5) bond length is 2.19 Å. In the sixth Co site, Co(6) is bonded to one O(2), one O(3), one O(5), one F(2), one F(4), and one F(6) atom to form a mixture of distorted corner and edge-sharing CoO3F3 octahedra. The corner-sharing octahedral tilt angles range from 43-54°. The Co(6)-O(2) bond length is 1.77 Å. The Co(6)-O(3) bond length is 1.87 Å. The Co(6)-O(5) bond length is 1.88 Å. The Co(6)-F(2) bond length is 2.06 Å. The Co(6)-F(4) bond length is 2.05 Å. The Co(6)-F(6) bond length is 2.34 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Co(1), one Co(3), and one Co(5) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Co(2), one Co(3), and one Co(6) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Co(3), one Co(5), and one Co(6) atom. In the fourth O site, O(4) is bonded in a trigonal pyramidal geometry to one Mg(1), one Co(1), one Co(4), and one Co(5) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Co(2), one Co(4), and one Co(6) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Co(1), one Co(2), and one Co(4) atom. There are six inequivalent F sites. In the first F site, F(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(1), one Co(2), and one Co(4) atom. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Co(2), one Co(4), and one Co(6) atom. In the third F site, F(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Co(1), one Co(4), and one Co(5) atom. In the fourth F site, F(4) is bonded in a distorted T-shaped geometry to one Co(3), one Co(5), and one Co(6) atom. In the fifth F site, F(5) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Co(1), one Co(3), and one Co(5) atom. In the sixth F site, F(6) is bonded in a 3-coordinate geometry to one Co(2), one Co(3), and one Co(6) atom.