MgFe6(O5F)2 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(1), two equivalent O(3), two equivalent O(5), and one F(1) atom to form MgO5F octahedra that share corners with two equivalent Fe(1)O4F2 octahedra, corners with two equivalent Fe(3)O5F octahedra, corners with two equivalent Fe(2)O5 square pyramids, corners with two equivalent Fe(5)O3F2 trigonal bipyramids, edges with two equivalent Mg(1)O5F octahedra,  a faceface with one Fe(1)O4F2 octahedra, and  a faceface with one Fe(3)O5F octahedra. The corner-sharing octahedral tilt angles range from 24-32°. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), two equivalent O(5), and two equivalent F(2) atoms to form distorted FeO4F2 octahedra that share corners with two equivalent Mg(1)O5F octahedra, corners with two equivalent Fe(4)O5F octahedra, corners with four equivalent Fe(2)O5 square pyramids, edges with two equivalent Fe(1)O4F2 octahedra, and  a faceface with one Mg(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 32-47°. In the second Fe site, Fe(2) is bonded to one O(9), two equivalent O(1), and two equivalent O(2) atoms to form distorted FeO5 square pyramids that share corners with two equivalent Mg(1)O5F octahedra, corners with two equivalent Fe(6)O6 octahedra, corners with four equivalent Fe(1)O4F2 octahedra, and edges with two equivalent Fe(2)O5 square pyramids. The corner-sharing octahedral tilt angles range from 49-65°. In the third Fe site, Fe(3) is bonded to one O(6), two equivalent O(3), two equivalent O(4), and one F(1) atom to form distorted FeO5F octahedra that share corners with two equivalent Mg(1)O5F octahedra, corners with two equivalent Fe(4)O5F octahedra, corners with four equivalent Fe(5)O3F2 trigonal bipyramids, edges with two equivalent Fe(3)O5F octahedra, and  a faceface with one Mg(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 24-50°. In the fourth Fe site, Fe(4) is bonded to one O(4), two equivalent O(10), two equivalent O(7), and one F(2) atom to form FeO5F octahedra that share corners with two equivalent Fe(1)O4F2 octahedra, corners with two equivalent Fe(3)O5F octahedra, corners with four equivalent Fe(6)O6 octahedra, and edges with two equivalent Fe(4)O5F octahedra. The corner-sharing octahedral tilt angles range from 47-50°. In the fifth Fe site, Fe(5) is bonded to one O(8), two equivalent O(6), and two equivalent F(1) atoms to form distorted FeO3F2 trigonal bipyramids that share corners with two equivalent Mg(1)O5F octahedra, corners with two equivalent Fe(6)O6 octahedra, corners with four equivalent Fe(3)O5F octahedra, and edges with two equivalent Fe(5)O3F2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 49-57°. In the sixth Fe site, Fe(6) is bonded to one O(10), one O(7), two equivalent O(8), and two equivalent O(9) atoms to form FeO6 octahedra that share corners with four equivalent Fe(4)O5F octahedra, corners with two equivalent Fe(2)O5 square pyramids, corners with two equivalent Fe(5)O3F2 trigonal bipyramids, and edges with two equivalent Fe(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-50°. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Fe(1), and two equivalent Fe(2) atoms to form distorted corner-sharing OMgFe3 tetrahedra. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(1) and two equivalent Fe(2) atoms. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Fe(3) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(4) and two equivalent Fe(3) atoms. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Fe(1) atoms. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(3) and two equivalent Fe(5) atoms. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Fe(6) and two equivalent Fe(4) atoms. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Fe(5) and two equivalent Fe(6) atoms. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Fe(2) and two equivalent Fe(6) atoms. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Fe(6) and two equivalent Fe(4) atoms. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(3), and two equivalent Fe(5) atoms. In the second F site, F(2) is bonded in a 3-coordinate geometry to one Fe(4) and two equivalent Fe(1) atoms.
MgFe6(O5F)2 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(1), two equivalent O(3), two equivalent O(5), and one F(1) atom to form MgO5F octahedra that share corners with two equivalent Fe(1)O4F2 octahedra, corners with two equivalent Fe(3)O5F octahedra, corners with two equivalent Fe(2)O5 square pyramids, corners with two equivalent Fe(5)O3F2 trigonal bipyramids, edges with two equivalent Mg(1)O5F octahedra,  a faceface with one Fe(1)O4F2 octahedra, and  a faceface with one Fe(3)O5F octahedra. The corner-sharing octahedral tilt angles range from 24-32°. The Mg(1)-O(1) bond length is 2.09 Å. Both Mg(1)-O(3) bond lengths are 2.06 Å. Both Mg(1)-O(5) bond lengths are 2.12 Å. The Mg(1)-F(1) bond length is 2.22 Å. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), two equivalent O(5), and two equivalent F(2) atoms to form distorted FeO4F2 octahedra that share corners with two equivalent Mg(1)O5F octahedra, corners with two equivalent Fe(4)O5F octahedra, corners with four equivalent Fe(2)O5 square pyramids, edges with two equivalent Fe(1)O4F2 octahedra, and  a faceface with one Mg(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 32-47°. The Fe(1)-O(1) bond length is 2.26 Å. The Fe(1)-O(2) bond length is 1.95 Å. Both Fe(1)-O(5) bond lengths are 1.99 Å. Both Fe(1)-F(2) bond lengths are 2.03 Å. In the second Fe site, Fe(2) is bonded to one O(9), two equivalent O(1), and two equivalent O(2) atoms to form distorted FeO5 square pyramids that share corners with two equivalent Mg(1)O5F octahedra, corners with two equivalent Fe(6)O6 octahedra, corners with four equivalent Fe(1)O4F2 octahedra, and edges with two equivalent Fe(2)O5 square pyramids. The corner-sharing octahedral tilt angles range from 49-65°. The Fe(2)-O(9) bond length is 1.93 Å. Both Fe(2)-O(1) bond lengths are 1.98 Å. Both Fe(2)-O(2) bond lengths are 1.96 Å. In the third Fe site, Fe(3) is bonded to one O(6), two equivalent O(3), two equivalent O(4), and one F(1) atom to form distorted FeO5F octahedra that share corners with two equivalent Mg(1)O5F octahedra, corners with two equivalent Fe(4)O5F octahedra, corners with four equivalent Fe(5)O3F2 trigonal bipyramids, edges with two equivalent Fe(3)O5F octahedra, and  a faceface with one Mg(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 24-50°. The Fe(3)-O(6) bond length is 1.95 Å. Both Fe(3)-O(3) bond lengths are 2.03 Å. Both Fe(3)-O(4) bond lengths are 1.94 Å. The Fe(3)-F(1) bond length is 2.34 Å. In the fourth Fe site, Fe(4) is bonded to one O(4), two equivalent O(10), two equivalent O(7), and one F(2) atom to form FeO5F octahedra that share corners with two equivalent Fe(1)O4F2 octahedra, corners with two equivalent Fe(3)O5F octahedra, corners with four equivalent Fe(6)O6 octahedra, and edges with two equivalent Fe(4)O5F octahedra. The corner-sharing octahedral tilt angles range from 47-50°. The Fe(4)-O(4) bond length is 2.00 Å. Both Fe(4)-O(10) bond lengths are 1.93 Å. Both Fe(4)-O(7) bond lengths are 1.93 Å. The Fe(4)-F(2) bond length is 2.35 Å. In the fifth Fe site, Fe(5) is bonded to one O(8), two equivalent O(6), and two equivalent F(1) atoms to form distorted FeO3F2 trigonal bipyramids that share corners with two equivalent Mg(1)O5F octahedra, corners with two equivalent Fe(6)O6 octahedra, corners with four equivalent Fe(3)O5F octahedra, and edges with two equivalent Fe(5)O3F2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 49-57°. The Fe(5)-O(8) bond length is 1.87 Å. Both Fe(5)-O(6) bond lengths are 1.89 Å. Both Fe(5)-F(1) bond lengths are 2.10 Å. In the sixth Fe site, Fe(6) is bonded to one O(10), one O(7), two equivalent O(8), and two equivalent O(9) atoms to form FeO6 octahedra that share corners with four equivalent Fe(4)O5F octahedra, corners with two equivalent Fe(2)O5 square pyramids, corners with two equivalent Fe(5)O3F2 trigonal bipyramids, and edges with two equivalent Fe(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-50°. The Fe(6)-O(10) bond length is 2.10 Å. The Fe(6)-O(7) bond length is 2.12 Å. Both Fe(6)-O(8) bond lengths are 1.94 Å. Both Fe(6)-O(9) bond lengths are 1.92 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Fe(1), and two equivalent Fe(2) atoms to form distorted corner-sharing OMgFe3 tetrahedra. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(1) and two equivalent Fe(2) atoms. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Fe(3) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(4) and two equivalent Fe(3) atoms. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Fe(1) atoms. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(3) and two equivalent Fe(5) atoms. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Fe(6) and two equivalent Fe(4) atoms. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Fe(5) and two equivalent Fe(6) atoms. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Fe(2) and two equivalent Fe(6) atoms. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Fe(6) and two equivalent Fe(4) atoms. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(3), and two equivalent Fe(5) atoms. In the second F site, F(2) is bonded in a 3-coordinate geometry to one Fe(4) and two equivalent Fe(1) atoms.