MgFe4(OF)4 is beta indium sulfide-derived structured and crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one O(4), one F(1), one F(3), and one F(4) atom to form MgO3F3 octahedra that share  a cornercorner with one Fe(1)O3F3 octahedra, corners with three equivalent Fe(2)O3F tetrahedra, edges with two equivalent Fe(1)O3F3 octahedra, edges with two equivalent Fe(3)O3F3 octahedra, and edges with two equivalent Fe(4)O3F3 octahedra. The corner-sharing octahedral tilt angles are 9°. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(4), one F(1), one F(2), and one F(4) atom to form FeO3F3 octahedra that share  a cornercorner with one Mg(1)O3F3 octahedra,  a cornercorner with one Fe(4)O3F3 octahedra, corners with two equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(2)O3F tetrahedra,  an edgeedge with one Fe(3)O3F3 octahedra, edges with two equivalent Mg(1)O3F3 octahedra, and edges with two equivalent Fe(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 7-23°. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), and one F(3) atom to form FeO3F tetrahedra that share corners with two equivalent Fe(1)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with three equivalent Mg(1)O3F3 octahedra, and corners with three equivalent Fe(3)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 45-62°. In the third Fe site, Fe(3) is bonded to one O(1), one O(3), one O(4), one F(1), one F(2), and one F(3) atom to form FeO3F3 octahedra that share corners with two equivalent Fe(1)O3F3 octahedra, corners with three equivalent Fe(2)O3F tetrahedra,  an edgeedge with one Fe(1)O3F3 octahedra, edges with two equivalent Mg(1)O3F3 octahedra, and edges with two equivalent Fe(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 7-23°. In the fourth Fe site, Fe(4) is bonded to one O(2), one O(3), one O(4), one F(1), one F(2), and one F(4) atom to form FeO3F3 octahedra that share  a cornercorner with one Fe(1)O3F3 octahedra, corners with two equivalent Fe(2)O3F tetrahedra, edges with two equivalent Mg(1)O3F3 octahedra, edges with two equivalent Fe(1)O3F3 octahedra, and edges with two equivalent Fe(3)O3F3 octahedra. The corner-sharing octahedral tilt angles are 8°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(2), and one Fe(3) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(2), and one Fe(4) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(4) atom. In the fourth O site, O(4) is bonded in a trigonal pyramidal geometry to one Mg(1), one Fe(1), one Fe(3), and one Fe(4) atom. There are four inequivalent F sites. In the first F site, F(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(3), and one Fe(4) atom. In the second F site, F(2) is bonded in a T-shaped geometry to one Fe(1), one Fe(3), and one Fe(4) atom. In the third F site, F(3) is bonded in a distorted trigonal planar geometry to one Mg(1), one Fe(2), and one Fe(3) atom. In the fourth F site, F(4) is bonded in a T-shaped geometry to one Mg(1), one Fe(1), and one Fe(4) atom.
MgFe4(OF)4 is beta indium sulfide-derived structured and crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one O(4), one F(1), one F(3), and one F(4) atom to form MgO3F3 octahedra that share  a cornercorner with one Fe(1)O3F3 octahedra, corners with three equivalent Fe(2)O3F tetrahedra, edges with two equivalent Fe(1)O3F3 octahedra, edges with two equivalent Fe(3)O3F3 octahedra, and edges with two equivalent Fe(4)O3F3 octahedra. The corner-sharing octahedral tilt angles are 9°. The Mg(1)-O(1) bond length is 2.01 Å. The Mg(1)-O(2) bond length is 2.16 Å. The Mg(1)-O(4) bond length is 2.03 Å. The Mg(1)-F(1) bond length is 2.04 Å. The Mg(1)-F(3) bond length is 2.18 Å. The Mg(1)-F(4) bond length is 1.98 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(4), one F(1), one F(2), and one F(4) atom to form FeO3F3 octahedra that share  a cornercorner with one Mg(1)O3F3 octahedra,  a cornercorner with one Fe(4)O3F3 octahedra, corners with two equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(2)O3F tetrahedra,  an edgeedge with one Fe(3)O3F3 octahedra, edges with two equivalent Mg(1)O3F3 octahedra, and edges with two equivalent Fe(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 7-23°. The Fe(1)-O(1) bond length is 2.13 Å. The Fe(1)-O(2) bond length is 2.10 Å. The Fe(1)-O(4) bond length is 2.03 Å. The Fe(1)-F(1) bond length is 2.41 Å. The Fe(1)-F(2) bond length is 2.21 Å. The Fe(1)-F(4) bond length is 2.24 Å. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), and one F(3) atom to form FeO3F tetrahedra that share corners with two equivalent Fe(1)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with three equivalent Mg(1)O3F3 octahedra, and corners with three equivalent Fe(3)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 45-62°. The Fe(2)-O(1) bond length is 1.88 Å. The Fe(2)-O(2) bond length is 1.94 Å. The Fe(2)-O(3) bond length is 1.89 Å. The Fe(2)-F(3) bond length is 1.98 Å. In the third Fe site, Fe(3) is bonded to one O(1), one O(3), one O(4), one F(1), one F(2), and one F(3) atom to form FeO3F3 octahedra that share corners with two equivalent Fe(1)O3F3 octahedra, corners with three equivalent Fe(2)O3F tetrahedra,  an edgeedge with one Fe(1)O3F3 octahedra, edges with two equivalent Mg(1)O3F3 octahedra, and edges with two equivalent Fe(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 7-23°. The Fe(3)-O(1) bond length is 2.14 Å. The Fe(3)-O(3) bond length is 2.08 Å. The Fe(3)-O(4) bond length is 2.09 Å. The Fe(3)-F(1) bond length is 2.26 Å. The Fe(3)-F(2) bond length is 2.13 Å. The Fe(3)-F(3) bond length is 2.21 Å. In the fourth Fe site, Fe(4) is bonded to one O(2), one O(3), one O(4), one F(1), one F(2), and one F(4) atom to form FeO3F3 octahedra that share  a cornercorner with one Fe(1)O3F3 octahedra, corners with two equivalent Fe(2)O3F tetrahedra, edges with two equivalent Mg(1)O3F3 octahedra, edges with two equivalent Fe(1)O3F3 octahedra, and edges with two equivalent Fe(3)O3F3 octahedra. The corner-sharing octahedral tilt angles are 8°. The Fe(4)-O(2) bond length is 2.05 Å. The Fe(4)-O(3) bond length is 1.95 Å. The Fe(4)-O(4) bond length is 1.98 Å. The Fe(4)-F(1) bond length is 2.07 Å. The Fe(4)-F(2) bond length is 2.00 Å. The Fe(4)-F(4) bond length is 2.11 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(2), and one Fe(3) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(2), and one Fe(4) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(4) atom. In the fourth O site, O(4) is bonded in a trigonal pyramidal geometry to one Mg(1), one Fe(1), one Fe(3), and one Fe(4) atom. There are four inequivalent F sites. In the first F site, F(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(3), and one Fe(4) atom. In the second F site, F(2) is bonded in a T-shaped geometry to one Fe(1), one Fe(3), and one Fe(4) atom. In the third F site, F(3) is bonded in a distorted trigonal planar geometry to one Mg(1), one Fe(2), and one Fe(3) atom. In the fourth F site, F(4) is bonded in a T-shaped geometry to one Mg(1), one Fe(1), and one Fe(4) atom.