Fe4O3F5 crystallizes in the monoclinic P2_1 space group. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), one F(3), one F(4), and two equivalent F(1) atoms to form distorted FeO2F4 octahedra that share corners with two equivalent Fe(1)O2F4 octahedra, corners with two equivalent Fe(2)O2F4 octahedra, corners with two equivalent Fe(4)O2F4 octahedra,  a cornercorner with one Fe(3)O3F2 square pyramid, and edges with two equivalent Fe(4)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 48-57°. In the second Fe site, Fe(2) is bonded to one O(2), one O(3), one F(4), one F(5), and two equivalent F(2) atoms to form FeO2F4 octahedra that share corners with two equivalent Fe(1)O2F4 octahedra, corners with two equivalent Fe(2)O2F4 octahedra, corners with two equivalent Fe(4)O2F4 octahedra, corners with two equivalent Fe(3)O3F2 square pyramids, and edges with two equivalent Fe(3)O3F2 square pyramids. The corner-sharing octahedral tilt angles range from 48-57°. In the third Fe site, Fe(3) is bonded to one O(3), two equivalent O(2), one F(2), and one F(5) atom to form distorted FeO3F2 square pyramids that share  a cornercorner with one Fe(1)O2F4 octahedra,  a cornercorner with one Fe(4)O2F4 octahedra, corners with two equivalent Fe(2)O2F4 octahedra, corners with two equivalent Fe(3)O3F2 square pyramids, and edges with two equivalent Fe(2)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 40-56°. In the fourth Fe site, Fe(4) is bonded to two equivalent O(1), one F(1), one F(3), one F(4), and one F(5) atom to form FeO2F4 octahedra that share corners with two equivalent Fe(1)O2F4 octahedra, corners with two equivalent Fe(2)O2F4 octahedra, corners with two equivalent Fe(4)O2F4 octahedra,  a cornercorner with one Fe(3)O3F2 square pyramid, and edges with two equivalent Fe(1)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 49-52°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(1) and two equivalent Fe(4) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(3) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(3) atom. There are five inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Fe(4) and two equivalent Fe(1) atoms. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to one Fe(3) and two equivalent Fe(2) atoms. In the third F site, F(3) is bonded in a water-like geometry to one Fe(1) and one Fe(4) atom. In the fourth F site, F(4) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(4) atom. In the fifth F site, F(5) is bonded in a distorted T-shaped geometry to one Fe(2), one Fe(3), and one Fe(4) atom.
Fe4O3F5 crystallizes in the monoclinic P2_1 space group. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), one F(3), one F(4), and two equivalent F(1) atoms to form distorted FeO2F4 octahedra that share corners with two equivalent Fe(1)O2F4 octahedra, corners with two equivalent Fe(2)O2F4 octahedra, corners with two equivalent Fe(4)O2F4 octahedra,  a cornercorner with one Fe(3)O3F2 square pyramid, and edges with two equivalent Fe(4)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 48-57°. The Fe(1)-O(1) bond length is 1.97 Å. The Fe(1)-O(3) bond length is 1.84 Å. The Fe(1)-F(3) bond length is 2.01 Å. The Fe(1)-F(4) bond length is 2.08 Å. There is one shorter (2.07 Å) and one longer (2.31 Å) Fe(1)-F(1) bond length. In the second Fe site, Fe(2) is bonded to one O(2), one O(3), one F(4), one F(5), and two equivalent F(2) atoms to form FeO2F4 octahedra that share corners with two equivalent Fe(1)O2F4 octahedra, corners with two equivalent Fe(2)O2F4 octahedra, corners with two equivalent Fe(4)O2F4 octahedra, corners with two equivalent Fe(3)O3F2 square pyramids, and edges with two equivalent Fe(3)O3F2 square pyramids. The corner-sharing octahedral tilt angles range from 48-57°. The Fe(2)-O(2) bond length is 2.04 Å. The Fe(2)-O(3) bond length is 2.06 Å. The Fe(2)-F(4) bond length is 2.18 Å. The Fe(2)-F(5) bond length is 2.21 Å. There is one shorter (2.09 Å) and one longer (2.17 Å) Fe(2)-F(2) bond length. In the third Fe site, Fe(3) is bonded to one O(3), two equivalent O(2), one F(2), and one F(5) atom to form distorted FeO3F2 square pyramids that share  a cornercorner with one Fe(1)O2F4 octahedra,  a cornercorner with one Fe(4)O2F4 octahedra, corners with two equivalent Fe(2)O2F4 octahedra, corners with two equivalent Fe(3)O3F2 square pyramids, and edges with two equivalent Fe(2)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 40-56°. The Fe(3)-O(3) bond length is 1.96 Å. There is one shorter (1.88 Å) and one longer (1.92 Å) Fe(3)-O(2) bond length. The Fe(3)-F(2) bond length is 2.05 Å. The Fe(3)-F(5) bond length is 2.11 Å. In the fourth Fe site, Fe(4) is bonded to two equivalent O(1), one F(1), one F(3), one F(4), and one F(5) atom to form FeO2F4 octahedra that share corners with two equivalent Fe(1)O2F4 octahedra, corners with two equivalent Fe(2)O2F4 octahedra, corners with two equivalent Fe(4)O2F4 octahedra,  a cornercorner with one Fe(3)O3F2 square pyramid, and edges with two equivalent Fe(1)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 49-52°. There is one shorter (1.93 Å) and one longer (1.95 Å) Fe(4)-O(1) bond length. The Fe(4)-F(1) bond length is 2.05 Å. The Fe(4)-F(3) bond length is 2.03 Å. The Fe(4)-F(4) bond length is 2.06 Å. The Fe(4)-F(5) bond length is 2.06 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) and two equivalent Fe(4) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(3) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(3) atom. There are five inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Fe(4) and two equivalent Fe(1) atoms. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to one Fe(3) and two equivalent Fe(2) atoms. In the third F site, F(3) is bonded in a water-like geometry to one Fe(1) and one Fe(4) atom. In the fourth F site, F(4) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(4) atom. In the fifth F site, F(5) is bonded in a distorted T-shaped geometry to one Fe(2), one Fe(3), and one Fe(4) atom.