MgFe6(O2F)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one O(7), one O(8), one F(2), and one F(3) atom to form MgO4F2 octahedra that share corners with two equivalent Fe(1)O4F2 octahedra, corners with two equivalent Fe(3)O4F2 octahedra, edges with two equivalent Fe(4)O4F2 octahedra, edges with two equivalent Fe(6)O4F2 octahedra, and faces with two equivalent Fe(2)O4F2 octahedra. The corner-sharing octahedral tilt angles are 45°. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), one O(5), one O(7), one F(1), and one F(4) atom to form FeO4F2 octahedra that share corners with two equivalent Mg(1)O4F2 octahedra, corners with four equivalent Fe(4)O4F2 octahedra, corners with four equivalent Fe(5)O4F2 octahedra,  an edgeedge with one Fe(2)O4F2 octahedra, and  an edgeedge with one Fe(3)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 43-61°. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(7), one O(8), one F(2), and one F(3) atom to form FeO4F2 octahedra that share corners with four equivalent Fe(4)O4F2 octahedra, corners with four equivalent Fe(6)O4F2 octahedra,  an edgeedge with one Fe(1)O4F2 octahedra,  an edgeedge with one Fe(3)O4F2 octahedra, and faces with two equivalent Mg(1)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 38-56°. In the third Fe site, Fe(3) is bonded to one O(2), one O(4), one O(6), one O(8), one F(1), and one F(4) atom to form FeO4F2 octahedra that share corners with two equivalent Mg(1)O4F2 octahedra, corners with four equivalent Fe(5)O4F2 octahedra, corners with four equivalent Fe(6)O4F2 octahedra,  an edgeedge with one Fe(1)O4F2 octahedra, and  an edgeedge with one Fe(2)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 43-61°. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(3), one O(5), one O(7), one F(2), and one F(3) atom to form FeO4F2 octahedra that share corners with four equivalent Fe(1)O4F2 octahedra, corners with four equivalent Fe(2)O4F2 octahedra,  an edgeedge with one Fe(5)O4F2 octahedra,  an edgeedge with one Fe(6)O4F2 octahedra, and edges with two equivalent Mg(1)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 38-61°. In the fifth Fe site, Fe(5) is bonded to one O(3), one O(4), one O(5), one O(6), one F(1), and one F(4) atom to form a mixture of corner and edge-sharing FeO4F2 octahedra. The corner-sharing octahedral tilt angles range from 43-52°. In the sixth Fe site, Fe(6) is bonded to one O(2), one O(4), one O(6), one O(8), one F(2), and one F(3) atom to form FeO4F2 octahedra that share corners with four equivalent Fe(2)O4F2 octahedra, corners with four equivalent Fe(3)O4F2 octahedra,  an edgeedge with one Fe(4)O4F2 octahedra,  an edgeedge with one Fe(5)O4F2 octahedra, and edges with two equivalent Mg(1)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 38-61°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(2), and one Fe(4) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(3), and one Fe(6) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(4), and one Fe(5) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Fe(3), one Fe(5), and one Fe(6) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(4), and one Fe(5) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Fe(3), one Fe(5), and one Fe(6) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(2), and one Fe(4) atom. In the eighth O site, O(8) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(3), and one Fe(6) atom. There are four inequivalent F sites. In the first F site, F(1) is bonded in a trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(5) atom. In the second F site, F(2) is bonded to one Mg(1), one Fe(2), one Fe(4), and one Fe(6) atom to form a mixture of distorted corner and edge-sharing FMgFe3 trigonal pyramids. In the third F site, F(3) is bonded to one Mg(1), one Fe(2), one Fe(4), and one Fe(6) atom to form a mixture of distorted corner and edge-sharing FMgFe3 trigonal pyramids. In the fourth F site, F(4) is bonded in a trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(5) atom.
MgFe6(O2F)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one O(7), one O(8), one F(2), and one F(3) atom to form MgO4F2 octahedra that share corners with two equivalent Fe(1)O4F2 octahedra, corners with two equivalent Fe(3)O4F2 octahedra, edges with two equivalent Fe(4)O4F2 octahedra, edges with two equivalent Fe(6)O4F2 octahedra, and faces with two equivalent Fe(2)O4F2 octahedra. The corner-sharing octahedral tilt angles are 45°. The Mg(1)-O(1) bond length is 2.05 Å. The Mg(1)-O(2) bond length is 2.06 Å. The Mg(1)-O(7) bond length is 2.06 Å. The Mg(1)-O(8) bond length is 2.06 Å. The Mg(1)-F(2) bond length is 1.94 Å. The Mg(1)-F(3) bond length is 1.94 Å. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), one O(5), one O(7), one F(1), and one F(4) atom to form FeO4F2 octahedra that share corners with two equivalent Mg(1)O4F2 octahedra, corners with four equivalent Fe(4)O4F2 octahedra, corners with four equivalent Fe(5)O4F2 octahedra,  an edgeedge with one Fe(2)O4F2 octahedra, and  an edgeedge with one Fe(3)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 43-61°. The Fe(1)-O(1) bond length is 2.01 Å. The Fe(1)-O(3) bond length is 1.94 Å. The Fe(1)-O(5) bond length is 1.95 Å. The Fe(1)-O(7) bond length is 2.02 Å. The Fe(1)-F(1) bond length is 2.07 Å. The Fe(1)-F(4) bond length is 2.08 Å. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(7), one O(8), one F(2), and one F(3) atom to form FeO4F2 octahedra that share corners with four equivalent Fe(4)O4F2 octahedra, corners with four equivalent Fe(6)O4F2 octahedra,  an edgeedge with one Fe(1)O4F2 octahedra,  an edgeedge with one Fe(3)O4F2 octahedra, and faces with two equivalent Mg(1)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 38-56°. The Fe(2)-O(1) bond length is 1.93 Å. The Fe(2)-O(2) bond length is 1.92 Å. The Fe(2)-O(7) bond length is 1.93 Å. The Fe(2)-O(8) bond length is 1.93 Å. The Fe(2)-F(2) bond length is 2.09 Å. The Fe(2)-F(3) bond length is 2.08 Å. In the third Fe site, Fe(3) is bonded to one O(2), one O(4), one O(6), one O(8), one F(1), and one F(4) atom to form FeO4F2 octahedra that share corners with two equivalent Mg(1)O4F2 octahedra, corners with four equivalent Fe(5)O4F2 octahedra, corners with four equivalent Fe(6)O4F2 octahedra,  an edgeedge with one Fe(1)O4F2 octahedra, and  an edgeedge with one Fe(2)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 43-61°. The Fe(3)-O(2) bond length is 2.02 Å. The Fe(3)-O(4) bond length is 1.96 Å. The Fe(3)-O(6) bond length is 1.96 Å. The Fe(3)-O(8) bond length is 2.02 Å. The Fe(3)-F(1) bond length is 2.07 Å. The Fe(3)-F(4) bond length is 2.07 Å. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(3), one O(5), one O(7), one F(2), and one F(3) atom to form FeO4F2 octahedra that share corners with four equivalent Fe(1)O4F2 octahedra, corners with four equivalent Fe(2)O4F2 octahedra,  an edgeedge with one Fe(5)O4F2 octahedra,  an edgeedge with one Fe(6)O4F2 octahedra, and edges with two equivalent Mg(1)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 38-61°. The Fe(4)-O(1) bond length is 2.11 Å. The Fe(4)-O(3) bond length is 1.89 Å. The Fe(4)-O(5) bond length is 1.88 Å. The Fe(4)-O(7) bond length is 2.10 Å. The Fe(4)-F(2) bond length is 2.19 Å. The Fe(4)-F(3) bond length is 2.19 Å. In the fifth Fe site, Fe(5) is bonded to one O(3), one O(4), one O(5), one O(6), one F(1), and one F(4) atom to form a mixture of corner and edge-sharing FeO4F2 octahedra. The corner-sharing octahedral tilt angles range from 43-52°. The Fe(5)-O(3) bond length is 2.03 Å. The Fe(5)-O(4) bond length is 2.01 Å. The Fe(5)-O(5) bond length is 2.03 Å. The Fe(5)-O(6) bond length is 2.01 Å. The Fe(5)-F(1) bond length is 2.10 Å. The Fe(5)-F(4) bond length is 2.10 Å. In the sixth Fe site, Fe(6) is bonded to one O(2), one O(4), one O(6), one O(8), one F(2), and one F(3) atom to form FeO4F2 octahedra that share corners with four equivalent Fe(2)O4F2 octahedra, corners with four equivalent Fe(3)O4F2 octahedra,  an edgeedge with one Fe(4)O4F2 octahedra,  an edgeedge with one Fe(5)O4F2 octahedra, and edges with two equivalent Mg(1)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 38-61°. The Fe(6)-O(2) bond length is 2.11 Å. The Fe(6)-O(4) bond length is 1.88 Å. The Fe(6)-O(6) bond length is 1.88 Å. The Fe(6)-O(8) bond length is 2.11 Å. The Fe(6)-F(2) bond length is 2.18 Å. The Fe(6)-F(3) bond length is 2.18 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(2), and one Fe(4) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(3), and one Fe(6) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(4), and one Fe(5) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Fe(3), one Fe(5), and one Fe(6) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(4), and one Fe(5) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Fe(3), one Fe(5), and one Fe(6) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(2), and one Fe(4) atom. In the eighth O site, O(8) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(3), and one Fe(6) atom. There are four inequivalent F sites. In the first F site, F(1) is bonded in a trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(5) atom. In the second F site, F(2) is bonded to one Mg(1), one Fe(2), one Fe(4), and one Fe(6) atom to form a mixture of distorted corner and edge-sharing FMgFe3 trigonal pyramids. In the third F site, F(3) is bonded to one Mg(1), one Fe(2), one Fe(4), and one Fe(6) atom to form a mixture of distorted corner and edge-sharing FMgFe3 trigonal pyramids. In the fourth F site, F(4) is bonded in a trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(5) atom.