Fe3(OF)2 crystallizes in the monoclinic Pm space group. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one F(1), and one F(2) atom to form FeO2F2 tetrahedra that share  a cornercorner with one Fe(4)O2F4 octahedra,  a cornercorner with one Fe(5)O2F4 octahedra, corners with two equivalent Fe(2)O4F2 octahedra, corners with two equivalent Fe(3)O4F2 octahedra, and corners with two equivalent Fe(1)O2F2 tetrahedra. The corner-sharing octahedral tilt angles range from 56-73°. In the second Fe site, Fe(2) is bonded to two equivalent O(1), two equivalent O(2), one F(6), and one F(8) atom to form distorted FeO4F2 octahedra that share corners with two equivalent Fe(8)O2F2 tetrahedra, corners with four equivalent Fe(1)O2F2 tetrahedra, edges with two equivalent Fe(4)O2F4 octahedra, edges with two equivalent Fe(5)O2F4 octahedra, and edges with two equivalent Fe(3)O4F2 octahedra. In the third Fe site, Fe(3) is bonded to two equivalent O(1), two equivalent O(2), one F(5), and one F(7) atom to form distorted FeO4F2 octahedra that share corners with two equivalent Fe(8)O2F2 tetrahedra, corners with four equivalent Fe(1)O2F2 tetrahedra, edges with two equivalent Fe(4)O2F4 octahedra, edges with two equivalent Fe(5)O2F4 octahedra, and edges with two equivalent Fe(2)O4F2 octahedra. In the fourth Fe site, Fe(4) is bonded to one O(2), one O(3), one F(3), one F(4), one F(5), and one F(6) atom to form FeO2F4 octahedra that share corners with four equivalent Fe(5)O2F4 octahedra,  a cornercorner with one Fe(1)O2F2 tetrahedra,  a cornercorner with one Fe(8)O2F2 tetrahedra,  an edgeedge with one Fe(2)O4F2 octahedra,  an edgeedge with one Fe(3)O4F2 octahedra, edges with two equivalent Fe(4)O2F4 octahedra, and edges with two equivalent Fe(5)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 3-6°. In the fifth Fe site, Fe(5) is bonded to one O(1), one O(4), one F(3), one F(4), one F(5), and one F(6) atom to form FeO2F4 octahedra that share corners with four equivalent Fe(4)O2F4 octahedra,  a cornercorner with one Fe(1)O2F2 tetrahedra,  a cornercorner with one Fe(8)O2F2 tetrahedra,  an edgeedge with one Fe(2)O4F2 octahedra,  an edgeedge with one Fe(3)O4F2 octahedra, edges with two equivalent Fe(4)O2F4 octahedra, and edges with two equivalent Fe(5)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 3-6°. In the sixth Fe site, Fe(6) is bonded in a 6-coordinate geometry to two equivalent O(3), two equivalent O(4), one F(1), and one F(4) atom. In the seventh Fe site, Fe(7) is bonded in a 6-coordinate geometry to two equivalent O(3), two equivalent O(4), one F(2), and one F(3) atom. In the eighth Fe site, Fe(8) is bonded to one O(3), one O(4), one F(7), and one F(8) atom to form FeO2F2 tetrahedra that share  a cornercorner with one Fe(4)O2F4 octahedra,  a cornercorner with one Fe(5)O2F4 octahedra,  a cornercorner with one Fe(2)O4F2 octahedra,  a cornercorner with one Fe(3)O4F2 octahedra, and corners with two equivalent Fe(8)O2F2 tetrahedra. The corner-sharing octahedral tilt angles range from 49-73°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Fe(1), one Fe(2), one Fe(3), and one Fe(5) atom to form OFe4 tetrahedra that share  a cornercorner with one F(3)Fe5 square pyramid,  a cornercorner with one F(4)Fe5 square pyramid,  a cornercorner with one O(4)Fe4 tetrahedra, corners with two equivalent O(1)Fe4 tetrahedra, corners with three equivalent O(2)Fe4 tetrahedra,  an edgeedge with one F(5)Fe5 square pyramid,  an edgeedge with one F(6)Fe5 square pyramid, and  an edgeedge with one O(2)Fe4 tetrahedra. In the second O site, O(2) is bonded to one Fe(1), one Fe(2), one Fe(3), and one Fe(4) atom to form OFe4 tetrahedra that share  a cornercorner with one F(3)Fe5 square pyramid,  a cornercorner with one F(4)Fe5 square pyramid,  a cornercorner with one O(3)Fe4 tetrahedra, corners with two equivalent O(2)Fe4 tetrahedra, corners with three equivalent O(1)Fe4 tetrahedra,  an edgeedge with one F(5)Fe5 square pyramid,  an edgeedge with one F(6)Fe5 square pyramid, and  an edgeedge with one O(1)Fe4 tetrahedra. In the third O site, O(3) is bonded to one Fe(4), one Fe(6), one Fe(7), and one Fe(8) atom to form OFe4 tetrahedra that share  a cornercorner with one F(5)Fe5 square pyramid,  a cornercorner with one F(6)Fe5 square pyramid,  a cornercorner with one O(2)Fe4 tetrahedra, corners with two equivalent O(3)Fe4 tetrahedra, corners with three equivalent O(4)Fe4 tetrahedra,  an edgeedge with one F(3)Fe5 square pyramid,  an edgeedge with one F(4)Fe5 square pyramid, and  an edgeedge with one O(4)Fe4 tetrahedra. In the fourth O site, O(4) is bonded to one Fe(5), one Fe(6), one Fe(7), and one Fe(8) atom to form OFe4 tetrahedra that share  a cornercorner with one F(5)Fe5 square pyramid,  a cornercorner with one F(6)Fe5 square pyramid,  a cornercorner with one O(1)Fe4 tetrahedra, corners with two equivalent O(4)Fe4 tetrahedra, corners with three equivalent O(3)Fe4 tetrahedra,  an edgeedge with one F(3)Fe5 square pyramid,  an edgeedge with one F(4)Fe5 square pyramid, and  an edgeedge with one O(3)Fe4 tetrahedra. There are eight inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Fe(6) and two equivalent Fe(1) atoms. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to one Fe(7) and two equivalent Fe(1) atoms. In the third F site, F(3) is bonded to one Fe(7), two equivalent Fe(4), and two equivalent Fe(5) atoms to form FFe5 square pyramids that share corners with four equivalent F(5)Fe5 square pyramids, corners with two equivalent O(1)Fe4 tetrahedra, corners with two equivalent O(2)Fe4 tetrahedra, edges with two equivalent F(4)Fe5 square pyramids, edges with two equivalent F(6)Fe5 square pyramids, edges with two equivalent O(3)Fe4 tetrahedra, and edges with two equivalent O(4)Fe4 tetrahedra. In the fourth F site, F(4) is bonded to one Fe(6), two equivalent Fe(4), and two equivalent Fe(5) atoms to form FFe5 square pyramids that share corners with four equivalent F(6)Fe5 square pyramids, corners with two equivalent O(1)Fe4 tetrahedra, corners with two equivalent O(2)Fe4 tetrahedra, edges with two equivalent F(3)Fe5 square pyramids, edges with two equivalent F(5)Fe5 square pyramids, edges with two equivalent O(3)Fe4 tetrahedra, and edges with two equivalent O(4)Fe4 tetrahedra. In the fifth F site, F(5) is bonded to one Fe(3), two equivalent Fe(4), and two equivalent Fe(5) atoms to form FFe5 square pyramids that share corners with four equivalent F(3)Fe5 square pyramids, corners with two equivalent O(3)Fe4 tetrahedra, corners with two equivalent O(4)Fe4 tetrahedra, edges with two equivalent F(4)Fe5 square pyramids, edges with two equivalent F(6)Fe5 square pyramids, edges with two equivalent O(1)Fe4 tetrahedra, and edges with two equivalent O(2)Fe4 tetrahedra. In the sixth F site, F(6) is bonded to one Fe(2), two equivalent Fe(4), and two equivalent Fe(5) atoms to form FFe5 square pyramids that share corners with four equivalent F(4)Fe5 square pyramids, corners with two equivalent O(3)Fe4 tetrahedra, corners with two equivalent O(4)Fe4 tetrahedra, edges with two equivalent F(3)Fe5 square pyramids, edges with two equivalent F(5)Fe5 square pyramids, edges with two equivalent O(1)Fe4 tetrahedra, and edges with two equivalent O(2)Fe4 tetrahedra. In the seventh F site, F(7) is bonded in a distorted trigonal planar geometry to one Fe(3) and two equivalent Fe(8) atoms. In the eighth F site, F(8) is bonded in a distorted trigonal planar geometry to one Fe(2) and two equivalent Fe(8) atoms.
Fe3(OF)2 crystallizes in the monoclinic Pm space group. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one F(1), and one F(2) atom to form FeO2F2 tetrahedra that share  a cornercorner with one Fe(4)O2F4 octahedra,  a cornercorner with one Fe(5)O2F4 octahedra, corners with two equivalent Fe(2)O4F2 octahedra, corners with two equivalent Fe(3)O4F2 octahedra, and corners with two equivalent Fe(1)O2F2 tetrahedra. The corner-sharing octahedral tilt angles range from 56-73°. The Fe(1)-O(1) bond length is 1.96 Å. The Fe(1)-O(2) bond length is 1.97 Å. The Fe(1)-F(1) bond length is 2.14 Å. The Fe(1)-F(2) bond length is 2.12 Å. In the second Fe site, Fe(2) is bonded to two equivalent O(1), two equivalent O(2), one F(6), and one F(8) atom to form distorted FeO4F2 octahedra that share corners with two equivalent Fe(8)O2F2 tetrahedra, corners with four equivalent Fe(1)O2F2 tetrahedra, edges with two equivalent Fe(4)O2F4 octahedra, edges with two equivalent Fe(5)O2F4 octahedra, and edges with two equivalent Fe(3)O4F2 octahedra. Both Fe(2)-O(1) bond lengths are 2.18 Å. Both Fe(2)-O(2) bond lengths are 2.19 Å. The Fe(2)-F(6) bond length is 2.47 Å. The Fe(2)-F(8) bond length is 2.05 Å. In the third Fe site, Fe(3) is bonded to two equivalent O(1), two equivalent O(2), one F(5), and one F(7) atom to form distorted FeO4F2 octahedra that share corners with two equivalent Fe(8)O2F2 tetrahedra, corners with four equivalent Fe(1)O2F2 tetrahedra, edges with two equivalent Fe(4)O2F4 octahedra, edges with two equivalent Fe(5)O2F4 octahedra, and edges with two equivalent Fe(2)O4F2 octahedra. Both Fe(3)-O(1) bond lengths are 2.15 Å. Both Fe(3)-O(2) bond lengths are 2.12 Å. The Fe(3)-F(5) bond length is 2.44 Å. The Fe(3)-F(7) bond length is 2.17 Å. In the fourth Fe site, Fe(4) is bonded to one O(2), one O(3), one F(3), one F(4), one F(5), and one F(6) atom to form FeO2F4 octahedra that share corners with four equivalent Fe(5)O2F4 octahedra,  a cornercorner with one Fe(1)O2F2 tetrahedra,  a cornercorner with one Fe(8)O2F2 tetrahedra,  an edgeedge with one Fe(2)O4F2 octahedra,  an edgeedge with one Fe(3)O4F2 octahedra, edges with two equivalent Fe(4)O2F4 octahedra, and edges with two equivalent Fe(5)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 3-6°. The Fe(4)-O(2) bond length is 1.99 Å. The Fe(4)-O(3) bond length is 1.98 Å. The Fe(4)-F(3) bond length is 2.26 Å. The Fe(4)-F(4) bond length is 2.28 Å. The Fe(4)-F(5) bond length is 2.29 Å. The Fe(4)-F(6) bond length is 2.26 Å. In the fifth Fe site, Fe(5) is bonded to one O(1), one O(4), one F(3), one F(4), one F(5), and one F(6) atom to form FeO2F4 octahedra that share corners with four equivalent Fe(4)O2F4 octahedra,  a cornercorner with one Fe(1)O2F2 tetrahedra,  a cornercorner with one Fe(8)O2F2 tetrahedra,  an edgeedge with one Fe(2)O4F2 octahedra,  an edgeedge with one Fe(3)O4F2 octahedra, edges with two equivalent Fe(4)O2F4 octahedra, and edges with two equivalent Fe(5)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 3-6°. The Fe(5)-O(1) bond length is 1.99 Å. The Fe(5)-O(4) bond length is 1.98 Å. The Fe(5)-F(3) bond length is 2.26 Å. The Fe(5)-F(4) bond length is 2.29 Å. The Fe(5)-F(5) bond length is 2.28 Å. The Fe(5)-F(6) bond length is 2.26 Å. In the sixth Fe site, Fe(6) is bonded in a 6-coordinate geometry to two equivalent O(3), two equivalent O(4), one F(1), and one F(4) atom. Both Fe(6)-O(3) bond lengths are 2.19 Å. Both Fe(6)-O(4) bond lengths are 2.18 Å. The Fe(6)-F(1) bond length is 2.06 Å. The Fe(6)-F(4) bond length is 2.50 Å. In the seventh Fe site, Fe(7) is bonded in a 6-coordinate geometry to two equivalent O(3), two equivalent O(4), one F(2), and one F(3) atom. Both Fe(7)-O(3) bond lengths are 2.15 Å. Both Fe(7)-O(4) bond lengths are 2.16 Å. The Fe(7)-F(2) bond length is 2.06 Å. The Fe(7)-F(3) bond length is 2.51 Å. In the eighth Fe site, Fe(8) is bonded to one O(3), one O(4), one F(7), and one F(8) atom to form FeO2F2 tetrahedra that share  a cornercorner with one Fe(4)O2F4 octahedra,  a cornercorner with one Fe(5)O2F4 octahedra,  a cornercorner with one Fe(2)O4F2 octahedra,  a cornercorner with one Fe(3)O4F2 octahedra, and corners with two equivalent Fe(8)O2F2 tetrahedra. The corner-sharing octahedral tilt angles range from 49-73°. The Fe(8)-O(3) bond length is 1.98 Å. The Fe(8)-O(4) bond length is 1.96 Å. The Fe(8)-F(7) bond length is 2.09 Å. The Fe(8)-F(8) bond length is 2.15 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Fe(1), one Fe(2), one Fe(3), and one Fe(5) atom to form OFe4 tetrahedra that share  a cornercorner with one F(3)Fe5 square pyramid,  a cornercorner with one F(4)Fe5 square pyramid,  a cornercorner with one O(4)Fe4 tetrahedra, corners with two equivalent O(1)Fe4 tetrahedra, corners with three equivalent O(2)Fe4 tetrahedra,  an edgeedge with one F(5)Fe5 square pyramid,  an edgeedge with one F(6)Fe5 square pyramid, and  an edgeedge with one O(2)Fe4 tetrahedra. In the second O site, O(2) is bonded to one Fe(1), one Fe(2), one Fe(3), and one Fe(4) atom to form OFe4 tetrahedra that share  a cornercorner with one F(3)Fe5 square pyramid,  a cornercorner with one F(4)Fe5 square pyramid,  a cornercorner with one O(3)Fe4 tetrahedra, corners with two equivalent O(2)Fe4 tetrahedra, corners with three equivalent O(1)Fe4 tetrahedra,  an edgeedge with one F(5)Fe5 square pyramid,  an edgeedge with one F(6)Fe5 square pyramid, and  an edgeedge with one O(1)Fe4 tetrahedra. In the third O site, O(3) is bonded to one Fe(4), one Fe(6), one Fe(7), and one Fe(8) atom to form OFe4 tetrahedra that share  a cornercorner with one F(5)Fe5 square pyramid,  a cornercorner with one F(6)Fe5 square pyramid,  a cornercorner with one O(2)Fe4 tetrahedra, corners with two equivalent O(3)Fe4 tetrahedra, corners with three equivalent O(4)Fe4 tetrahedra,  an edgeedge with one F(3)Fe5 square pyramid,  an edgeedge with one F(4)Fe5 square pyramid, and  an edgeedge with one O(4)Fe4 tetrahedra. In the fourth O site, O(4) is bonded to one Fe(5), one Fe(6), one Fe(7), and one Fe(8) atom to form OFe4 tetrahedra that share  a cornercorner with one F(5)Fe5 square pyramid,  a cornercorner with one F(6)Fe5 square pyramid,  a cornercorner with one O(1)Fe4 tetrahedra, corners with two equivalent O(4)Fe4 tetrahedra, corners with three equivalent O(3)Fe4 tetrahedra,  an edgeedge with one F(3)Fe5 square pyramid,  an edgeedge with one F(4)Fe5 square pyramid, and  an edgeedge with one O(3)Fe4 tetrahedra. There are eight inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Fe(6) and two equivalent Fe(1) atoms. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to one Fe(7) and two equivalent Fe(1) atoms. In the third F site, F(3) is bonded to one Fe(7), two equivalent Fe(4), and two equivalent Fe(5) atoms to form FFe5 square pyramids that share corners with four equivalent F(5)Fe5 square pyramids, corners with two equivalent O(1)Fe4 tetrahedra, corners with two equivalent O(2)Fe4 tetrahedra, edges with two equivalent F(4)Fe5 square pyramids, edges with two equivalent F(6)Fe5 square pyramids, edges with two equivalent O(3)Fe4 tetrahedra, and edges with two equivalent O(4)Fe4 tetrahedra. In the fourth F site, F(4) is bonded to one Fe(6), two equivalent Fe(4), and two equivalent Fe(5) atoms to form FFe5 square pyramids that share corners with four equivalent F(6)Fe5 square pyramids, corners with two equivalent O(1)Fe4 tetrahedra, corners with two equivalent O(2)Fe4 tetrahedra, edges with two equivalent F(3)Fe5 square pyramids, edges with two equivalent F(5)Fe5 square pyramids, edges with two equivalent O(3)Fe4 tetrahedra, and edges with two equivalent O(4)Fe4 tetrahedra. In the fifth F site, F(5) is bonded to one Fe(3), two equivalent Fe(4), and two equivalent Fe(5) atoms to form FFe5 square pyramids that share corners with four equivalent F(3)Fe5 square pyramids, corners with two equivalent O(3)Fe4 tetrahedra, corners with two equivalent O(4)Fe4 tetrahedra, edges with two equivalent F(4)Fe5 square pyramids, edges with two equivalent F(6)Fe5 square pyramids, edges with two equivalent O(1)Fe4 tetrahedra, and edges with two equivalent O(2)Fe4 tetrahedra. In the sixth F site, F(6) is bonded to one Fe(2), two equivalent Fe(4), and two equivalent Fe(5) atoms to form FFe5 square pyramids that share corners with four equivalent F(4)Fe5 square pyramids, corners with two equivalent O(3)Fe4 tetrahedra, corners with two equivalent O(4)Fe4 tetrahedra, edges with two equivalent F(3)Fe5 square pyramids, edges with two equivalent F(5)Fe5 square pyramids, edges with two equivalent O(1)Fe4 tetrahedra, and edges with two equivalent O(2)Fe4 tetrahedra. In the seventh F site, F(7) is bonded in a distorted trigonal planar geometry to one Fe(3) and two equivalent Fe(8) atoms. In the eighth F site, F(8) is bonded in a distorted trigonal planar geometry to one Fe(2) and two equivalent Fe(8) atoms.