MgFe6(OF)6 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(3), two equivalent O(1), one F(3), and two equivalent F(6) atoms to form distorted MgO3F3 octahedra that share corners with four equivalent Fe(1)O3F3 octahedra, corners with two equivalent Fe(4)O4F square pyramids, edges with two equivalent Mg(1)O3F3 octahedra, edges with two equivalent Fe(6)O3F3 octahedra, and faces with two equivalent Fe(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 35-48°. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), two equivalent O(1), one F(3), and two equivalent F(6) atoms to form distorted FeO3F3 octahedra that share corners with four equivalent Mg(1)O3F3 octahedra, corners with four equivalent Fe(6)O3F3 octahedra, corners with two equivalent Fe(4)O4F square pyramids, edges with two equivalent Fe(1)O3F3 octahedra, and faces with two equivalent Mg(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 35-57°. In the second Fe site, Fe(2) is bonded to one O(4), one O(6), two equivalent F(1), and two equivalent F(4) atoms to form FeO2F4 octahedra that share corners with four equivalent Fe(4)O4F square pyramids, corners with four equivalent Fe(5)O4F square pyramids, and edges with two equivalent Fe(2)O2F4 octahedra. In the third Fe site, Fe(3) is bonded to one O(2), one O(5), two equivalent F(2), and two equivalent F(5) atoms to form FeO2F4 octahedra that share corners with four equivalent Fe(6)O3F3 octahedra, corners with two equivalent Fe(5)O4F square pyramids, and edges with two equivalent Fe(3)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 49-54°. In the fourth Fe site, Fe(4) is bonded to two equivalent O(3), two equivalent O(6), and one F(1) atom to form distorted FeO4F square pyramids that share corners with two equivalent Mg(1)O3F3 octahedra, corners with two equivalent Fe(1)O3F3 octahedra, corners with four equivalent Fe(2)O2F4 octahedra, and edges with two equivalent Fe(4)O4F square pyramids. The corner-sharing octahedral tilt angles range from 46-69°. In the fifth Fe site, Fe(5) is bonded to two equivalent O(4), two equivalent O(5), and one F(4) atom to form distorted FeO4F square pyramids that share corners with two equivalent Fe(3)O2F4 octahedra, corners with four equivalent Fe(2)O2F4 octahedra, and edges with two equivalent Fe(5)O4F square pyramids. The corner-sharing octahedral tilt angles range from 45-52°. In the sixth Fe site, Fe(6) is bonded to one O(1), two equivalent O(2), one F(5), and two equivalent F(3) atoms to form distorted FeO3F3 octahedra that share corners with four equivalent Fe(3)O2F4 octahedra, corners with four equivalent Fe(1)O3F3 octahedra, edges with two equivalent Mg(1)O3F3 octahedra, and edges with two equivalent Fe(6)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 41-57°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Mg(1), one Fe(6), and two equivalent Fe(1) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(3) and two equivalent Fe(6) atoms. In the third O site, O(3) is bonded to one Mg(1), one Fe(1), and two equivalent Fe(4) atoms to form distorted corner-sharing OMgFe3 tetrahedra. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(5) atoms. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Fe(3) and two equivalent Fe(5) atoms. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(4) atoms. There are six inequivalent F sites. In the first F site, F(1) is bonded in a 3-coordinate geometry to one Fe(4) and two equivalent Fe(2) atoms. In the second F site, F(2) is bonded in a water-like geometry to two equivalent Fe(3) atoms. In the third F site, F(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(1), and two equivalent Fe(6) atoms. In the fourth F site, F(4) is bonded in a distorted T-shaped geometry to one Fe(5) and two equivalent Fe(2) atoms. In the fifth F site, F(5) is bonded in a distorted T-shaped geometry to one Fe(6) and two equivalent Fe(3) atoms. In the sixth F site, F(6) is bonded in a 4-coordinate geometry to two equivalent Mg(1) and two equivalent Fe(1) atoms.
MgFe6(OF)6 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(3), two equivalent O(1), one F(3), and two equivalent F(6) atoms to form distorted MgO3F3 octahedra that share corners with four equivalent Fe(1)O3F3 octahedra, corners with two equivalent Fe(4)O4F square pyramids, edges with two equivalent Mg(1)O3F3 octahedra, edges with two equivalent Fe(6)O3F3 octahedra, and faces with two equivalent Fe(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 35-48°. The Mg(1)-O(3) bond length is 1.98 Å. Both Mg(1)-O(1) bond lengths are 2.15 Å. The Mg(1)-F(3) bond length is 2.05 Å. Both Mg(1)-F(6) bond lengths are 2.03 Å. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), two equivalent O(1), one F(3), and two equivalent F(6) atoms to form distorted FeO3F3 octahedra that share corners with four equivalent Mg(1)O3F3 octahedra, corners with four equivalent Fe(6)O3F3 octahedra, corners with two equivalent Fe(4)O4F square pyramids, edges with two equivalent Fe(1)O3F3 octahedra, and faces with two equivalent Mg(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 35-57°. The Fe(1)-O(3) bond length is 2.00 Å. Both Fe(1)-O(1) bond lengths are 2.16 Å. The Fe(1)-F(3) bond length is 2.15 Å. Both Fe(1)-F(6) bond lengths are 2.29 Å. In the second Fe site, Fe(2) is bonded to one O(4), one O(6), two equivalent F(1), and two equivalent F(4) atoms to form FeO2F4 octahedra that share corners with four equivalent Fe(4)O4F square pyramids, corners with four equivalent Fe(5)O4F square pyramids, and edges with two equivalent Fe(2)O2F4 octahedra. The Fe(2)-O(4) bond length is 2.01 Å. The Fe(2)-O(6) bond length is 2.02 Å. Both Fe(2)-F(1) bond lengths are 2.26 Å. Both Fe(2)-F(4) bond lengths are 2.19 Å. In the third Fe site, Fe(3) is bonded to one O(2), one O(5), two equivalent F(2), and two equivalent F(5) atoms to form FeO2F4 octahedra that share corners with four equivalent Fe(6)O3F3 octahedra, corners with two equivalent Fe(5)O4F square pyramids, and edges with two equivalent Fe(3)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 49-54°. The Fe(3)-O(2) bond length is 2.10 Å. The Fe(3)-O(5) bond length is 1.84 Å. Both Fe(3)-F(2) bond lengths are 1.99 Å. Both Fe(3)-F(5) bond lengths are 2.14 Å. In the fourth Fe site, Fe(4) is bonded to two equivalent O(3), two equivalent O(6), and one F(1) atom to form distorted FeO4F square pyramids that share corners with two equivalent Mg(1)O3F3 octahedra, corners with two equivalent Fe(1)O3F3 octahedra, corners with four equivalent Fe(2)O2F4 octahedra, and edges with two equivalent Fe(4)O4F square pyramids. The corner-sharing octahedral tilt angles range from 46-69°. Both Fe(4)-O(3) bond lengths are 2.11 Å. Both Fe(4)-O(6) bond lengths are 1.94 Å. The Fe(4)-F(1) bond length is 1.95 Å. In the fifth Fe site, Fe(5) is bonded to two equivalent O(4), two equivalent O(5), and one F(4) atom to form distorted FeO4F square pyramids that share corners with two equivalent Fe(3)O2F4 octahedra, corners with four equivalent Fe(2)O2F4 octahedra, and edges with two equivalent Fe(5)O4F square pyramids. The corner-sharing octahedral tilt angles range from 45-52°. Both Fe(5)-O(4) bond lengths are 1.94 Å. Both Fe(5)-O(5) bond lengths are 2.07 Å. The Fe(5)-F(4) bond length is 1.99 Å. In the sixth Fe site, Fe(6) is bonded to one O(1), two equivalent O(2), one F(5), and two equivalent F(3) atoms to form distorted FeO3F3 octahedra that share corners with four equivalent Fe(3)O2F4 octahedra, corners with four equivalent Fe(1)O3F3 octahedra, edges with two equivalent Mg(1)O3F3 octahedra, and edges with two equivalent Fe(6)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 41-57°. The Fe(6)-O(1) bond length is 1.96 Å. Both Fe(6)-O(2) bond lengths are 1.90 Å. The Fe(6)-F(5) bond length is 2.14 Å. Both Fe(6)-F(3) bond lengths are 2.34 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Mg(1), one Fe(6), and two equivalent Fe(1) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(3) and two equivalent Fe(6) atoms. In the third O site, O(3) is bonded to one Mg(1), one Fe(1), and two equivalent Fe(4) atoms to form distorted corner-sharing OMgFe3 tetrahedra. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(5) atoms. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Fe(3) and two equivalent Fe(5) atoms. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(4) atoms. There are six inequivalent F sites. In the first F site, F(1) is bonded in a 3-coordinate geometry to one Fe(4) and two equivalent Fe(2) atoms. In the second F site, F(2) is bonded in a water-like geometry to two equivalent Fe(3) atoms. In the third F site, F(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(1), and two equivalent Fe(6) atoms. In the fourth F site, F(4) is bonded in a distorted T-shaped geometry to one Fe(5) and two equivalent Fe(2) atoms. In the fifth F site, F(5) is bonded in a distorted T-shaped geometry to one Fe(6) and two equivalent Fe(3) atoms. In the sixth F site, F(6) is bonded in a 4-coordinate geometry to two equivalent Mg(1) and two equivalent Fe(1) atoms.