MgFe6(OF)6 crystallizes in the monoclinic P2/m space group. Mg(1) is bonded to four equivalent O(1) and two equivalent F(3) atoms to form MgO4F2 octahedra that share corners with four equivalent Fe(1)O4F2 octahedra, edges with two equivalent Mg(1)O4F2 octahedra, edges with four equivalent Fe(3)O3F3 octahedra, and faces with two equivalent Fe(1)O4F2 octahedra. The corner-sharing octahedral tilt angles are 41°. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to four equivalent O(1) and two equivalent F(3) atoms to form distorted FeO4F2 octahedra that share corners with four equivalent Mg(1)O4F2 octahedra, corners with eight equivalent Fe(3)O3F3 octahedra, edges with two equivalent Fe(1)O4F2 octahedra, and faces with two equivalent Mg(1)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 41-56°. In the second Fe site, Fe(2) is bonded to one O(2), one O(3), two equivalent F(1), and two equivalent F(2) atoms to form FeO2F4 octahedra that share corners with four equivalent Fe(3)O3F3 octahedra, corners with four equivalent Fe(4)O4F2 octahedra, and edges with two equivalent Fe(2)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 48-52°. In the third Fe site, Fe(3) is bonded to one O(1), two equivalent O(2), one F(1), and two equivalent F(3) atoms to form distorted FeO3F3 octahedra that share corners with four equivalent Fe(2)O2F4 octahedra, corners with four equivalent Fe(1)O4F2 octahedra, edges with two equivalent Mg(1)O4F2 octahedra, and edges with two equivalent Fe(3)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 45-56°. In the fourth Fe site, Fe(4) is bonded to four equivalent O(3) and two equivalent F(2) atoms to form FeO4F2 octahedra that share corners with eight equivalent Fe(2)O2F4 octahedra and edges with two equivalent Fe(4)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 48-50°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1), one Fe(3), and two equivalent Fe(1) atoms to form a mixture of distorted edge and corner-sharing OMg2Fe3 square pyramids. 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(2) and two equivalent Fe(4) atoms. There are three inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Fe(3) and two equivalent Fe(2) atoms. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to one Fe(4) and two equivalent Fe(2) atoms. In the third F site, F(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(1), and two equivalent Fe(3) atoms.
MgFe6(OF)6 crystallizes in the monoclinic P2/m space group. Mg(1) is bonded to four equivalent O(1) and two equivalent F(3) atoms to form MgO4F2 octahedra that share corners with four equivalent Fe(1)O4F2 octahedra, edges with two equivalent Mg(1)O4F2 octahedra, edges with four equivalent Fe(3)O3F3 octahedra, and faces with two equivalent Fe(1)O4F2 octahedra. The corner-sharing octahedral tilt angles are 41°. All Mg(1)-O(1) bond lengths are 2.11 Å. Both Mg(1)-F(3) bond lengths are 1.97 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to four equivalent O(1) and two equivalent F(3) atoms to form distorted FeO4F2 octahedra that share corners with four equivalent Mg(1)O4F2 octahedra, corners with eight equivalent Fe(3)O3F3 octahedra, edges with two equivalent Fe(1)O4F2 octahedra, and faces with two equivalent Mg(1)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 41-56°. All Fe(1)-O(1) bond lengths are 2.13 Å. Both Fe(1)-F(3) bond lengths are 2.37 Å. In the second Fe site, Fe(2) is bonded to one O(2), one O(3), two equivalent F(1), and two equivalent F(2) atoms to form FeO2F4 octahedra that share corners with four equivalent Fe(3)O3F3 octahedra, corners with four equivalent Fe(4)O4F2 octahedra, and edges with two equivalent Fe(2)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 48-52°. The Fe(2)-O(2) bond length is 1.92 Å. The Fe(2)-O(3) bond length is 1.93 Å. Both Fe(2)-F(1) bond lengths are 2.07 Å. Both Fe(2)-F(2) bond lengths are 2.06 Å. In the third Fe site, Fe(3) is bonded to one O(1), two equivalent O(2), one F(1), and two equivalent F(3) atoms to form distorted FeO3F3 octahedra that share corners with four equivalent Fe(2)O2F4 octahedra, corners with four equivalent Fe(1)O4F2 octahedra, edges with two equivalent Mg(1)O4F2 octahedra, and edges with two equivalent Fe(3)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 45-56°. The Fe(3)-O(1) bond length is 2.07 Å. Both Fe(3)-O(2) bond lengths are 1.95 Å. The Fe(3)-F(1) bond length is 2.24 Å. Both Fe(3)-F(3) bond lengths are 2.23 Å. In the fourth Fe site, Fe(4) is bonded to four equivalent O(3) and two equivalent F(2) atoms to form FeO4F2 octahedra that share corners with eight equivalent Fe(2)O2F4 octahedra and edges with two equivalent Fe(4)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 48-50°. All Fe(4)-O(3) bond lengths are 2.01 Å. Both Fe(4)-F(2) bond lengths are 2.22 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1), one Fe(3), and two equivalent Fe(1) atoms to form a mixture of distorted edge and corner-sharing OMg2Fe3 square pyramids. 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(2) and two equivalent Fe(4) atoms. There are three inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Fe(3) and two equivalent Fe(2) atoms. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to one Fe(4) and two equivalent Fe(2) atoms. In the third F site, F(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(1), and two equivalent Fe(3) atoms.