MgCo6(O5F)2 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(5), one O(8), two equivalent O(2), and two equivalent O(9) atoms to form MgO6 octahedra that share corners with four equivalent Co(1)O6 octahedra, corners with two equivalent Co(6)O4F square pyramids, corners with two equivalent Co(4)O3F2 trigonal bipyramids, edges with two equivalent Mg(1)O6 octahedra, and faces with two equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-40°. There are six inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(5), one O(8), two equivalent O(2), and two equivalent O(9) atoms to form CoO6 octahedra that share corners with four equivalent Mg(1)O6 octahedra, corners with two equivalent Co(6)O4F square pyramids, corners with two equivalent Co(4)O3F2 trigonal bipyramids, edges with two equivalent Co(1)O6 octahedra, and faces with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-40°. In the second Co site, Co(2) is bonded to one O(6), two equivalent O(1), two equivalent O(10), and one F(1) atom to form CoO5F octahedra that share corners with four equivalent Co(5)O6 octahedra, corners with four equivalent Co(4)O3F2 trigonal bipyramids, and edges with two equivalent Co(2)O5F octahedra. The corner-sharing octahedral tilt angles range from 50-51°. In the third Co site, Co(3) is bonded to one O(4), one O(7), two equivalent O(3), and two equivalent F(2) atoms to form CoO4F2 octahedra that share corners with four equivalent Co(5)O6 octahedra, corners with four equivalent Co(6)O4F square pyramids, and edges with two equivalent Co(3)O4F2 octahedra. The corner-sharing octahedral tilt angles are 51°. In the fourth Co site, Co(4) is bonded to one O(1), two equivalent O(5), and two equivalent F(1) atoms to form distorted CoO3F2 trigonal bipyramids that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Co(1)O6 octahedra, corners with four equivalent Co(2)O5F octahedra, and edges with two equivalent Co(4)O3F2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 45-63°. In the fifth Co site, Co(5) is bonded to one O(10), one O(3), two equivalent O(6), and two equivalent O(7) atoms to form CoO6 octahedra that share corners with four equivalent Co(3)O4F2 octahedra, corners with four equivalent Co(2)O5F octahedra, and edges with two equivalent Co(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-51°. In the sixth Co site, Co(6) is bonded to two equivalent O(4), two equivalent O(8), and one F(2) atom to form CoO4F square pyramids that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Co(1)O6 octahedra, corners with four equivalent Co(3)O4F2 octahedra, and edges with two equivalent Co(6)O4F square pyramids. The corner-sharing octahedral tilt angles range from 48-66°. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Co(4) and two equivalent Co(2) atoms. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Co(1) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Co(5) and two equivalent Co(3) atoms. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Co(3) and two equivalent Co(6) atoms. In the fifth O site, O(5) is bonded to one Mg(1), one Co(1), and two equivalent Co(4) atoms to form distorted corner-sharing OMgCo3 tetrahedra. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Co(2) and two equivalent Co(5) atoms. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Co(3) and two equivalent Co(5) atoms. In the eighth O site, O(8) is bonded to one Mg(1), one Co(1), and two equivalent Co(6) atoms to form distorted corner-sharing OMgCo3 tetrahedra. In the ninth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Co(1) atoms. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Co(5) and two equivalent Co(2) atoms. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Co(2) and two equivalent Co(4) atoms. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Co(6) and two equivalent Co(3) atoms.
MgCo6(O5F)2 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(5), one O(8), two equivalent O(2), and two equivalent O(9) atoms to form MgO6 octahedra that share corners with four equivalent Co(1)O6 octahedra, corners with two equivalent Co(6)O4F square pyramids, corners with two equivalent Co(4)O3F2 trigonal bipyramids, edges with two equivalent Mg(1)O6 octahedra, and faces with two equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-40°. The Mg(1)-O(5) bond length is 2.05 Å. The Mg(1)-O(8) bond length is 2.05 Å. Both Mg(1)-O(2) bond lengths are 2.08 Å. Both Mg(1)-O(9) bond lengths are 2.06 Å. There are six inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(5), one O(8), two equivalent O(2), and two equivalent O(9) atoms to form CoO6 octahedra that share corners with four equivalent Mg(1)O6 octahedra, corners with two equivalent Co(6)O4F square pyramids, corners with two equivalent Co(4)O3F2 trigonal bipyramids, edges with two equivalent Co(1)O6 octahedra, and faces with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-40°. The Co(1)-O(5) bond length is 1.87 Å. The Co(1)-O(8) bond length is 1.93 Å. Both Co(1)-O(2) bond lengths are 1.91 Å. Both Co(1)-O(9) bond lengths are 1.91 Å. In the second Co site, Co(2) is bonded to one O(6), two equivalent O(1), two equivalent O(10), and one F(1) atom to form CoO5F octahedra that share corners with four equivalent Co(5)O6 octahedra, corners with four equivalent Co(4)O3F2 trigonal bipyramids, and edges with two equivalent Co(2)O5F octahedra. The corner-sharing octahedral tilt angles range from 50-51°. The Co(2)-O(6) bond length is 2.01 Å. Both Co(2)-O(1) bond lengths are 1.87 Å. Both Co(2)-O(10) bond lengths are 1.87 Å. The Co(2)-F(1) bond length is 2.25 Å. In the third Co site, Co(3) is bonded to one O(4), one O(7), two equivalent O(3), and two equivalent F(2) atoms to form CoO4F2 octahedra that share corners with four equivalent Co(5)O6 octahedra, corners with four equivalent Co(6)O4F square pyramids, and edges with two equivalent Co(3)O4F2 octahedra. The corner-sharing octahedral tilt angles are 51°. The Co(3)-O(4) bond length is 1.87 Å. The Co(3)-O(7) bond length is 1.93 Å. Both Co(3)-O(3) bond lengths are 1.87 Å. Both Co(3)-F(2) bond lengths are 2.05 Å. In the fourth Co site, Co(4) is bonded to one O(1), two equivalent O(5), and two equivalent F(1) atoms to form distorted CoO3F2 trigonal bipyramids that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Co(1)O6 octahedra, corners with four equivalent Co(2)O5F octahedra, and edges with two equivalent Co(4)O3F2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 45-63°. The Co(4)-O(1) bond length is 1.94 Å. Both Co(4)-O(5) bond lengths are 1.95 Å. Both Co(4)-F(1) bond lengths are 2.03 Å. In the fifth Co site, Co(5) is bonded to one O(10), one O(3), two equivalent O(6), and two equivalent O(7) atoms to form CoO6 octahedra that share corners with four equivalent Co(3)O4F2 octahedra, corners with four equivalent Co(2)O5F octahedra, and edges with two equivalent Co(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-51°. The Co(5)-O(10) bond length is 1.93 Å. The Co(5)-O(3) bond length is 1.93 Å. Both Co(5)-O(6) bond lengths are 1.87 Å. Both Co(5)-O(7) bond lengths are 1.88 Å. In the sixth Co site, Co(6) is bonded to two equivalent O(4), two equivalent O(8), and one F(2) atom to form CoO4F square pyramids that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Co(1)O6 octahedra, corners with four equivalent Co(3)O4F2 octahedra, and edges with two equivalent Co(6)O4F square pyramids. The corner-sharing octahedral tilt angles range from 48-66°. Both Co(6)-O(4) bond lengths are 1.87 Å. Both Co(6)-O(8) bond lengths are 1.93 Å. The Co(6)-F(2) bond length is 2.11 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Co(4) and two equivalent Co(2) atoms. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Co(1) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Co(5) and two equivalent Co(3) atoms. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Co(3) and two equivalent Co(6) atoms. In the fifth O site, O(5) is bonded to one Mg(1), one Co(1), and two equivalent Co(4) atoms to form distorted corner-sharing OMgCo3 tetrahedra. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Co(2) and two equivalent Co(5) atoms. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Co(3) and two equivalent Co(5) atoms. In the eighth O site, O(8) is bonded to one Mg(1), one Co(1), and two equivalent Co(6) atoms to form distorted corner-sharing OMgCo3 tetrahedra. In the ninth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Co(1) atoms. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Co(5) and two equivalent Co(2) atoms. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Co(2) and two equivalent Co(4) atoms. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Co(6) and two equivalent Co(3) atoms.