MgFe6(O5F)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(4), one O(6), one O(7), one F(1), and one F(2) atom to form MgO4F2 octahedra that share corners with two equivalent Fe(6)O4F2 octahedra,  a cornercorner with one Fe(1)O5 square pyramid,  a cornercorner with one Fe(4)O5 square pyramid, and edges with two equivalent Fe(5)O4F2 octahedra. The corner-sharing octahedral tilt angles are 50°. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(10), one O(5), one O(8), and one O(9) atom to form distorted FeO5 square pyramids that share  a cornercorner with one Mg(1)O4F2 octahedra, corners with three equivalent Fe(6)O4F2 octahedra,  an edgeedge with one Fe(5)O4F2 octahedra, and  an edgeedge with one Fe(4)O5 square pyramid. The corner-sharing octahedral tilt angles range from 45-74°. In the second Fe site, Fe(2) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), one O(6), one O(8), and one F(2) atom. In the third Fe site, Fe(3) is bonded in a 6-coordinate geometry to one O(2), one O(4), one O(5), one O(6), one O(7), and one F(1) atom. In the fourth Fe site, Fe(4) is bonded to one O(10), one O(2), one O(3), one O(7), and one O(9) atom to form distorted FeO5 square pyramids that share  a cornercorner with one Mg(1)O4F2 octahedra, corners with three equivalent Fe(6)O4F2 octahedra,  an edgeedge with one Fe(5)O4F2 octahedra, and  an edgeedge with one Fe(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 45-74°. In the fifth Fe site, Fe(5) is bonded to one O(1), one O(2), one O(7), one O(8), one F(1), and one F(2) atom to form FeO4F2 octahedra that share corners with two equivalent Fe(6)O4F2 octahedra, edges with two equivalent Mg(1)O4F2 octahedra,  an edgeedge with one Fe(1)O5 square pyramid, and  an edgeedge with one Fe(4)O5 square pyramid. The corner-sharing octahedral tilt angles are 47°. In the sixth Fe site, Fe(6) is bonded to one O(10), one O(3), one O(5), one O(9), one F(1), and one F(2) atom to form FeO4F2 octahedra that share corners with two equivalent Mg(1)O4F2 octahedra, corners with two equivalent Fe(5)O4F2 octahedra, corners with three equivalent Fe(1)O5 square pyramids, and corners with three equivalent Fe(4)O5 square pyramids. The corner-sharing octahedral tilt angles range from 47-50°. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Fe(1), one Fe(2), and one Fe(5) atom to form corner-sharing OMgFe3 trigonal pyramids. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(3), one Fe(4), and one Fe(5) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(2), one Fe(4), and one Fe(6) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(2), and one Fe(3) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(6) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(2), and one Fe(3) atom. In the seventh O site, O(7) is bonded to one Mg(1), one Fe(3), one Fe(4), and one Fe(5) atom to form corner-sharing OMgFe3 trigonal pyramids. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(5) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Fe(1), one Fe(4), and one Fe(6) atom. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Fe(1), one Fe(4), and one Fe(6) atom. 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), one Fe(5), and one Fe(6) atom. In the second F site, F(2) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(5), and one Fe(6) atom.
MgFe6(O5F)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(4), one O(6), one O(7), one F(1), and one F(2) atom to form MgO4F2 octahedra that share corners with two equivalent Fe(6)O4F2 octahedra,  a cornercorner with one Fe(1)O5 square pyramid,  a cornercorner with one Fe(4)O5 square pyramid, and edges with two equivalent Fe(5)O4F2 octahedra. The corner-sharing octahedral tilt angles are 50°. The Mg(1)-O(1) bond length is 2.01 Å. The Mg(1)-O(4) bond length is 2.00 Å. The Mg(1)-O(6) bond length is 2.00 Å. The Mg(1)-O(7) bond length is 2.01 Å. The Mg(1)-F(1) bond length is 2.09 Å. The Mg(1)-F(2) bond length is 2.09 Å. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(10), one O(5), one O(8), and one O(9) atom to form distorted FeO5 square pyramids that share  a cornercorner with one Mg(1)O4F2 octahedra, corners with three equivalent Fe(6)O4F2 octahedra,  an edgeedge with one Fe(5)O4F2 octahedra, and  an edgeedge with one Fe(4)O5 square pyramid. The corner-sharing octahedral tilt angles range from 45-74°. The Fe(1)-O(1) bond length is 2.01 Å. The Fe(1)-O(10) bond length is 1.98 Å. The Fe(1)-O(5) bond length is 1.97 Å. The Fe(1)-O(8) bond length is 1.96 Å. The Fe(1)-O(9) bond length is 1.97 Å. In the second Fe site, Fe(2) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), one O(6), one O(8), and one F(2) atom. The Fe(2)-O(1) bond length is 2.13 Å. The Fe(2)-O(3) bond length is 1.92 Å. The Fe(2)-O(4) bond length is 1.89 Å. The Fe(2)-O(6) bond length is 1.98 Å. The Fe(2)-O(8) bond length is 1.94 Å. The Fe(2)-F(2) bond length is 2.50 Å. In the third Fe site, Fe(3) is bonded in a 6-coordinate geometry to one O(2), one O(4), one O(5), one O(6), one O(7), and one F(1) atom. The Fe(3)-O(2) bond length is 1.95 Å. The Fe(3)-O(4) bond length is 1.98 Å. The Fe(3)-O(5) bond length is 1.92 Å. The Fe(3)-O(6) bond length is 1.89 Å. The Fe(3)-O(7) bond length is 2.13 Å. The Fe(3)-F(1) bond length is 2.52 Å. In the fourth Fe site, Fe(4) is bonded to one O(10), one O(2), one O(3), one O(7), and one O(9) atom to form distorted FeO5 square pyramids that share  a cornercorner with one Mg(1)O4F2 octahedra, corners with three equivalent Fe(6)O4F2 octahedra,  an edgeedge with one Fe(5)O4F2 octahedra, and  an edgeedge with one Fe(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 45-74°. The Fe(4)-O(10) bond length is 1.97 Å. The Fe(4)-O(2) bond length is 1.95 Å. The Fe(4)-O(3) bond length is 1.98 Å. The Fe(4)-O(7) bond length is 2.01 Å. The Fe(4)-O(9) bond length is 1.97 Å. In the fifth Fe site, Fe(5) is bonded to one O(1), one O(2), one O(7), one O(8), one F(1), and one F(2) atom to form FeO4F2 octahedra that share corners with two equivalent Fe(6)O4F2 octahedra, edges with two equivalent Mg(1)O4F2 octahedra,  an edgeedge with one Fe(1)O5 square pyramid, and  an edgeedge with one Fe(4)O5 square pyramid. The corner-sharing octahedral tilt angles are 47°. The Fe(5)-O(1) bond length is 1.98 Å. The Fe(5)-O(2) bond length is 1.94 Å. The Fe(5)-O(7) bond length is 1.98 Å. The Fe(5)-O(8) bond length is 1.94 Å. The Fe(5)-F(1) bond length is 2.18 Å. The Fe(5)-F(2) bond length is 2.19 Å. In the sixth Fe site, Fe(6) is bonded to one O(10), one O(3), one O(5), one O(9), one F(1), and one F(2) atom to form FeO4F2 octahedra that share corners with two equivalent Mg(1)O4F2 octahedra, corners with two equivalent Fe(5)O4F2 octahedra, corners with three equivalent Fe(1)O5 square pyramids, and corners with three equivalent Fe(4)O5 square pyramids. The corner-sharing octahedral tilt angles range from 47-50°. The Fe(6)-O(10) bond length is 2.00 Å. The Fe(6)-O(3) bond length is 1.98 Å. The Fe(6)-O(5) bond length is 1.98 Å. The Fe(6)-O(9) bond length is 2.00 Å. The Fe(6)-F(1) bond length is 2.14 Å. The Fe(6)-F(2) bond length is 2.14 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Fe(1), one Fe(2), and one Fe(5) atom to form corner-sharing OMgFe3 trigonal pyramids. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(3), one Fe(4), and one Fe(5) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(2), one Fe(4), and one Fe(6) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(2), and one Fe(3) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(6) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(2), and one Fe(3) atom. In the seventh O site, O(7) is bonded to one Mg(1), one Fe(3), one Fe(4), and one Fe(5) atom to form corner-sharing OMgFe3 trigonal pyramids. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(5) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Fe(1), one Fe(4), and one Fe(6) atom. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Fe(1), one Fe(4), and one Fe(6) atom. 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), one Fe(5), and one Fe(6) atom. In the second F site, F(2) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(5), and one Fe(6) atom.