MgCo6(OF)6 crystallizes in the triclinic P1 space group. Mg(1) is bonded to two equivalent O(2), two equivalent O(4), one F(2), and one F(6) atom to form distorted MgO4F2 octahedra that share corners with two equivalent Co(5)O3F tetrahedra, edges with two equivalent Mg(1)O4F2 octahedra, and edges with four equivalent Co(3)O2F4 octahedra. There are six inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent O(1), two equivalent O(6), one F(3), and one F(4) atom to form CoO4F2 octahedra that share corners with four equivalent Co(4)O3F3 octahedra and edges with two equivalent Co(1)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 45-56°. In the second Co site, Co(2) is bonded to one O(3), one O(5), two equivalent F(1), and two equivalent F(5) atoms to form CoO2F4 octahedra that share corners with four equivalent Co(4)O3F3 octahedra, corners with four equivalent Co(5)O3F tetrahedra, and edges with two equivalent Co(2)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 47-55°. In the third Co site, Co(3) is bonded to one O(2), one O(4), two equivalent F(2), and two equivalent F(6) atoms to form CoO2F4 octahedra that share  a cornercorner with one Co(5)O3F tetrahedra, edges with two equivalent Co(3)O2F4 octahedra, and edges with four equivalent Mg(1)O4F2 octahedra. In the fourth Co site, Co(4) is bonded to one O(6), two equivalent O(5), one F(1), and two equivalent F(3) atoms to form CoO3F3 octahedra that share corners with four equivalent Co(2)O2F4 octahedra, corners with four equivalent Co(1)O4F2 octahedra, and edges with two equivalent Co(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 45-56°. In the fifth Co site, Co(5) is bonded to one O(4), two equivalent O(3), and one F(5) atom to form CoO3F tetrahedra that share  a cornercorner with one Co(3)O2F4 octahedra, corners with two equivalent Mg(1)O4F2 octahedra, corners with four equivalent Co(2)O2F4 octahedra, and corners with two equivalent Co(5)O3F tetrahedra. The corner-sharing octahedral tilt angles range from 50-64°. In the sixth Co site, Co(6) is bonded in a 6-coordinate geometry to one O(1), two equivalent O(2), one F(6), and two equivalent F(4) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Co(6) and two equivalent Co(1) atoms. In the second O site, O(2) is bonded to two equivalent Mg(1), one Co(3), and two equivalent Co(6) atoms to form distorted edge-sharing OMg2Co3 trigonal bipyramids. In the third O site, O(3) is bonded in a trigonal planar geometry to one Co(2) and two equivalent Co(5) atoms. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mg(1), one Co(3), and one Co(5) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Co(2) and two equivalent Co(4) atoms. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Co(4) and two equivalent Co(1) atoms. There are six inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Co(4) and two equivalent Co(2) atoms. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Mg(1) and two equivalent Co(3) atoms. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one Co(1) and two equivalent Co(4) atoms. In the fourth F site, F(4) is bonded in a distorted trigonal planar geometry to one Co(1) and two equivalent Co(6) atoms. In the fifth F site, F(5) is bonded in a distorted T-shaped geometry to one Co(5) and two equivalent Co(2) atoms. In the sixth F site, F(6) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Co(6), and two equivalent Co(3) atoms.
MgCo6(OF)6 crystallizes in the triclinic P1 space group. Mg(1) is bonded to two equivalent O(2), two equivalent O(4), one F(2), and one F(6) atom to form distorted MgO4F2 octahedra that share corners with two equivalent Co(5)O3F tetrahedra, edges with two equivalent Mg(1)O4F2 octahedra, and edges with four equivalent Co(3)O2F4 octahedra. There is one shorter (2.21 Å) and one longer (2.25 Å) Mg(1)-O(2) bond length. Both Mg(1)-O(4) bond lengths are 2.00 Å. The Mg(1)-F(2) bond length is 1.93 Å. The Mg(1)-F(6) bond length is 2.02 Å. There are six inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent O(1), two equivalent O(6), one F(3), and one F(4) atom to form CoO4F2 octahedra that share corners with four equivalent Co(4)O3F3 octahedra and edges with two equivalent Co(1)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 45-56°. There is one shorter (1.95 Å) and one longer (1.96 Å) Co(1)-O(1) bond length. Both Co(1)-O(6) bond lengths are 1.91 Å. The Co(1)-F(3) bond length is 2.17 Å. The Co(1)-F(4) bond length is 2.30 Å. In the second Co site, Co(2) is bonded to one O(3), one O(5), two equivalent F(1), and two equivalent F(5) atoms to form CoO2F4 octahedra that share corners with four equivalent Co(4)O3F3 octahedra, corners with four equivalent Co(5)O3F tetrahedra, and edges with two equivalent Co(2)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 47-55°. The Co(2)-O(3) bond length is 2.04 Å. The Co(2)-O(5) bond length is 1.97 Å. There is one shorter (2.03 Å) and one longer (2.07 Å) Co(2)-F(1) bond length. There is one shorter (2.15 Å) and one longer (2.16 Å) Co(2)-F(5) bond length. In the third Co site, Co(3) is bonded to one O(2), one O(4), two equivalent F(2), and two equivalent F(6) atoms to form CoO2F4 octahedra that share  a cornercorner with one Co(5)O3F tetrahedra, edges with two equivalent Co(3)O2F4 octahedra, and edges with four equivalent Mg(1)O4F2 octahedra. The Co(3)-O(2) bond length is 2.03 Å. The Co(3)-O(4) bond length is 2.05 Å. Both Co(3)-F(2) bond lengths are 2.07 Å. Both Co(3)-F(6) bond lengths are 2.07 Å. In the fourth Co site, Co(4) is bonded to one O(6), two equivalent O(5), one F(1), and two equivalent F(3) atoms to form CoO3F3 octahedra that share corners with four equivalent Co(2)O2F4 octahedra, corners with four equivalent Co(1)O4F2 octahedra, and edges with two equivalent Co(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 45-56°. The Co(4)-O(6) bond length is 1.97 Å. There is one shorter (1.83 Å) and one longer (2.00 Å) Co(4)-O(5) bond length. The Co(4)-F(1) bond length is 2.17 Å. There is one shorter (2.08 Å) and one longer (2.10 Å) Co(4)-F(3) bond length. In the fifth Co site, Co(5) is bonded to one O(4), two equivalent O(3), and one F(5) atom to form CoO3F tetrahedra that share  a cornercorner with one Co(3)O2F4 octahedra, corners with two equivalent Mg(1)O4F2 octahedra, corners with four equivalent Co(2)O2F4 octahedra, and corners with two equivalent Co(5)O3F tetrahedra. The corner-sharing octahedral tilt angles range from 50-64°. The Co(5)-O(4) bond length is 1.84 Å. There is one shorter (1.81 Å) and one longer (1.88 Å) Co(5)-O(3) bond length. The Co(5)-F(5) bond length is 1.96 Å. In the sixth Co site, Co(6) is bonded in a 6-coordinate geometry to one O(1), two equivalent O(2), one F(6), and two equivalent F(4) atoms. The Co(6)-O(1) bond length is 1.80 Å. Both Co(6)-O(2) bond lengths are 2.06 Å. The Co(6)-F(6) bond length is 2.53 Å. There is one shorter (2.02 Å) and one longer (2.03 Å) Co(6)-F(4) bond length. There are six inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Co(6) and two equivalent Co(1) atoms. In the second O site, O(2) is bonded to two equivalent Mg(1), one Co(3), and two equivalent Co(6) atoms to form distorted edge-sharing OMg2Co3 trigonal bipyramids. In the third O site, O(3) is bonded in a trigonal planar geometry to one Co(2) and two equivalent Co(5) atoms. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mg(1), one Co(3), and one Co(5) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Co(2) and two equivalent Co(4) atoms. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Co(4) and two equivalent Co(1) atoms. There are six inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Co(4) and two equivalent Co(2) atoms. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Mg(1) and two equivalent Co(3) atoms. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one Co(1) and two equivalent Co(4) atoms. In the fourth F site, F(4) is bonded in a distorted trigonal planar geometry to one Co(1) and two equivalent Co(6) atoms. In the fifth F site, F(5) is bonded in a distorted T-shaped geometry to one Co(5) and two equivalent Co(2) atoms. In the sixth F site, F(6) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Co(6), and two equivalent Co(3) atoms.