MgFe6(O2F)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), one O(5), one F(1), and one F(2) atom to form distorted MgO2F2 tetrahedra that share  a cornercorner with one Fe(2)O4F2 octahedra, corners with two equivalent Fe(1)O3F3 octahedra,  a cornercorner with one Fe(3)O3F2 trigonal bipyramid, and  an edgeedge with one Fe(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 7-63°. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(5), one O(8), one F(1), one F(2), and one F(3) atom to form distorted FeO3F3 octahedra that share corners with two equivalent Mg(1)O2F2 tetrahedra,  a cornercorner with one Fe(3)O3F2 trigonal bipyramid,  an edgeedge with one Fe(2)O4F2 octahedra, and  an edgeedge with one Mg(1)O2F2 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(1), one O(3), one O(6), one O(8), one F(1), and one F(4) atom to form FeO4F2 octahedra that share  a cornercorner with one Mg(1)O2F2 tetrahedra, corners with three equivalent Fe(6)O5 trigonal bipyramids,  an edgeedge with one Fe(1)O3F3 octahedra, and  an edgeedge with one Fe(3)O3F2 trigonal bipyramid. In the third Fe site, Fe(3) is bonded to one O(1), one O(4), one O(7), one F(2), and one F(4) atom to form distorted FeO3F2 trigonal bipyramids that share  a cornercorner with one Fe(1)O3F3 octahedra,  a cornercorner with one Mg(1)O2F2 tetrahedra, corners with three equivalent Fe(6)O5 trigonal bipyramids, and  an edgeedge with one Fe(2)O4F2 octahedra. The corner-sharing octahedral tilt angles are 78°. In the fourth Fe site, Fe(4) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(5), one O(6), and one O(8) atom. In the fifth Fe site, Fe(5) is bonded in a 5-coordinate geometry to one O(2), one O(4), one O(5), one O(7), and one F(3) atom. In the sixth Fe site, Fe(6) is bonded to one O(1), one O(3), one O(4), one O(6), and one O(7) atom to form distorted FeO5 trigonal bipyramids that share corners with three equivalent Fe(2)O4F2 octahedra and corners with three equivalent Fe(3)O3F2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 42-54°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Fe(2), one Fe(3), and one Fe(6) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(1), 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 trigonal planar 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 trigonal pyramidal geometry to one Mg(1), one Fe(1), one Fe(4), and one Fe(5) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(2), one Fe(4), and one Fe(6) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(5), and one Fe(6) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(4) atom. There are four inequivalent F sites. In the first F site, F(1) is bonded in a T-shaped geometry to one Mg(1), one Fe(1), and one Fe(2) atom. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(1), and one Fe(3) atom. In the third F site, F(3) is bonded in a distorted bent 120 degrees geometry to one Fe(1) and one Fe(5) atom. In the fourth F site, F(4) is bonded in an L-shaped geometry to one Fe(2) and one Fe(3) atom.
MgFe6(O2F)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), one O(5), one F(1), and one F(2) atom to form distorted MgO2F2 tetrahedra that share  a cornercorner with one Fe(2)O4F2 octahedra, corners with two equivalent Fe(1)O3F3 octahedra,  a cornercorner with one Fe(3)O3F2 trigonal bipyramid, and  an edgeedge with one Fe(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 7-63°. The Mg(1)-O(2) bond length is 1.97 Å. The Mg(1)-O(5) bond length is 1.98 Å. The Mg(1)-F(1) bond length is 1.87 Å. The Mg(1)-F(2) bond length is 1.91 Å. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(5), one O(8), one F(1), one F(2), and one F(3) atom to form distorted FeO3F3 octahedra that share corners with two equivalent Mg(1)O2F2 tetrahedra,  a cornercorner with one Fe(3)O3F2 trigonal bipyramid,  an edgeedge with one Fe(2)O4F2 octahedra, and  an edgeedge with one Mg(1)O2F2 tetrahedra. The Fe(1)-O(2) bond length is 1.98 Å. The Fe(1)-O(5) bond length is 1.99 Å. The Fe(1)-O(8) bond length is 1.88 Å. The Fe(1)-F(1) bond length is 2.14 Å. The Fe(1)-F(2) bond length is 2.28 Å. The Fe(1)-F(3) bond length is 1.97 Å. In the second Fe site, Fe(2) is bonded to one O(1), one O(3), one O(6), one O(8), one F(1), and one F(4) atom to form FeO4F2 octahedra that share  a cornercorner with one Mg(1)O2F2 tetrahedra, corners with three equivalent Fe(6)O5 trigonal bipyramids,  an edgeedge with one Fe(1)O3F3 octahedra, and  an edgeedge with one Fe(3)O3F2 trigonal bipyramid. The Fe(2)-O(1) bond length is 2.07 Å. The Fe(2)-O(3) bond length is 1.95 Å. The Fe(2)-O(6) bond length is 1.95 Å. The Fe(2)-O(8) bond length is 2.12 Å. The Fe(2)-F(1) bond length is 2.08 Å. The Fe(2)-F(4) bond length is 1.96 Å. In the third Fe site, Fe(3) is bonded to one O(1), one O(4), one O(7), one F(2), and one F(4) atom to form distorted FeO3F2 trigonal bipyramids that share  a cornercorner with one Fe(1)O3F3 octahedra,  a cornercorner with one Mg(1)O2F2 tetrahedra, corners with three equivalent Fe(6)O5 trigonal bipyramids, and  an edgeedge with one Fe(2)O4F2 octahedra. The corner-sharing octahedral tilt angles are 78°. The Fe(3)-O(1) bond length is 1.90 Å. The Fe(3)-O(4) bond length is 1.95 Å. The Fe(3)-O(7) bond length is 1.95 Å. The Fe(3)-F(2) bond length is 2.06 Å. The Fe(3)-F(4) bond length is 2.01 Å. In the fourth Fe site, Fe(4) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(5), one O(6), and one O(8) atom. The Fe(4)-O(2) bond length is 2.34 Å. The Fe(4)-O(3) bond length is 1.92 Å. The Fe(4)-O(5) bond length is 2.21 Å. The Fe(4)-O(6) bond length is 1.92 Å. The Fe(4)-O(8) bond length is 1.91 Å. In the fifth Fe site, Fe(5) is bonded in a 5-coordinate geometry to one O(2), one O(4), one O(5), one O(7), and one F(3) atom. The Fe(5)-O(2) bond length is 2.09 Å. The Fe(5)-O(4) bond length is 1.91 Å. The Fe(5)-O(5) bond length is 2.17 Å. The Fe(5)-O(7) bond length is 1.91 Å. The Fe(5)-F(3) bond length is 1.97 Å. In the sixth Fe site, Fe(6) is bonded to one O(1), one O(3), one O(4), one O(6), and one O(7) atom to form distorted FeO5 trigonal bipyramids that share corners with three equivalent Fe(2)O4F2 octahedra and corners with three equivalent Fe(3)O3F2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 42-54°. The Fe(6)-O(1) bond length is 1.97 Å. The Fe(6)-O(3) bond length is 2.04 Å. The Fe(6)-O(4) bond length is 2.05 Å. The Fe(6)-O(6) bond length is 2.02 Å. The Fe(6)-O(7) bond length is 2.08 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Fe(2), one Fe(3), and one Fe(6) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(1), 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 trigonal planar 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 trigonal pyramidal geometry to one Mg(1), one Fe(1), one Fe(4), and one Fe(5) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(2), one Fe(4), and one Fe(6) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(5), and one Fe(6) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(4) atom. There are four inequivalent F sites. In the first F site, F(1) is bonded in a T-shaped geometry to one Mg(1), one Fe(1), and one Fe(2) atom. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(1), and one Fe(3) atom. In the third F site, F(3) is bonded in a distorted bent 120 degrees geometry to one Fe(1) and one Fe(5) atom. In the fourth F site, F(4) is bonded in an L-shaped geometry to one Fe(2) and one Fe(3) atom.