MgFe4O5F3 crystallizes in the monoclinic Cm space group. Mg(1) is bonded in a rectangular see-saw-like geometry to two equivalent O(3), one F(2), and one F(3) atom. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), two equivalent O(2), one F(1), one F(2), and one F(3) atom to form distorted FeO3F3 octahedra that share corners with three equivalent Fe(4)O4F trigonal bipyramids and edges with two equivalent Fe(2)O3F3 octahedra. In the second Fe site, Fe(2) is bonded to one O(1), two equivalent O(3), one F(1), one F(2), and one F(3) atom to form FeO3F3 octahedra that share corners with three equivalent Fe(4)O4F trigonal bipyramids and edges with two equivalent Fe(1)O3F3 octahedra. In the third Fe site, Fe(3) is bonded in a 5-coordinate geometry to one O(1), two equivalent O(2), and two equivalent O(3) atoms. In the fourth Fe site, Fe(4) is bonded to two equivalent O(2), two equivalent O(3), and one F(1) atom to form distorted corner-sharing FeO4F trigonal bipyramids. The corner-sharing octahedral tilt angles range from 41-51°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(3) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(3), and one Fe(4) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(3), and one Fe(4) atom. There are three inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(4) atom. In the second F site, F(2) is bonded in a T-shaped geometry to one Mg(1), one Fe(1), and one Fe(2) atom. In the third F site, F(3) is bonded in a T-shaped geometry to one Mg(1), one Fe(1), and one Fe(2) atom.
MgFe4O5F3 crystallizes in the monoclinic Cm space group. Mg(1) is bonded in a rectangular see-saw-like geometry to two equivalent O(3), one F(2), and one F(3) atom. Both Mg(1)-O(3) bond lengths are 1.98 Å. The Mg(1)-F(2) bond length is 1.91 Å. The Mg(1)-F(3) bond length is 1.91 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), two equivalent O(2), one F(1), one F(2), and one F(3) atom to form distorted FeO3F3 octahedra that share corners with three equivalent Fe(4)O4F trigonal bipyramids and edges with two equivalent Fe(2)O3F3 octahedra. The Fe(1)-O(1) bond length is 1.96 Å. Both Fe(1)-O(2) bond lengths are 1.90 Å. The Fe(1)-F(1) bond length is 2.26 Å. The Fe(1)-F(2) bond length is 2.17 Å. The Fe(1)-F(3) bond length is 2.36 Å. In the second Fe site, Fe(2) is bonded to one O(1), two equivalent O(3), one F(1), one F(2), and one F(3) atom to form FeO3F3 octahedra that share corners with three equivalent Fe(4)O4F trigonal bipyramids and edges with two equivalent Fe(1)O3F3 octahedra. The Fe(2)-O(1) bond length is 1.91 Å. Both Fe(2)-O(3) bond lengths are 1.95 Å. The Fe(2)-F(1) bond length is 2.05 Å. The Fe(2)-F(2) bond length is 2.15 Å. The Fe(2)-F(3) bond length is 2.15 Å. In the third Fe site, Fe(3) is bonded in a 5-coordinate geometry to one O(1), two equivalent O(2), and two equivalent O(3) atoms. The Fe(3)-O(1) bond length is 2.02 Å. Both Fe(3)-O(2) bond lengths are 2.08 Å. Both Fe(3)-O(3) bond lengths are 2.31 Å. In the fourth Fe site, Fe(4) is bonded to two equivalent O(2), two equivalent O(3), and one F(1) atom to form distorted corner-sharing FeO4F trigonal bipyramids. The corner-sharing octahedral tilt angles range from 41-51°. Both Fe(4)-O(2) bond lengths are 1.93 Å. Both Fe(4)-O(3) bond lengths are 2.06 Å. The Fe(4)-F(1) bond length is 2.08 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(3) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(3), and one Fe(4) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(3), and one Fe(4) atom. There are three inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(4) atom. In the second F site, F(2) is bonded in a T-shaped geometry to one Mg(1), one Fe(1), and one Fe(2) atom. In the third F site, F(3) is bonded in a T-shaped geometry to one Mg(1), one Fe(1), and one Fe(2) atom.