MgFe6(OF)6 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), two equivalent O(4), one F(6), and two equivalent F(2) atoms to form MgO3F3 octahedra that share corners with two equivalent Fe(6)O3F3 octahedra,  a cornercorner with one Fe(5)O3F tetrahedra, edges with two equivalent Mg(1)O3F3 octahedra, edges with four equivalent Fe(3)O3F3 octahedra, and  a faceface with one Fe(6)O3F3 octahedra. The corner-sharing octahedral tilt angles are 30°. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(3), one F(1), one F(3), and two equivalent F(4) atoms to form FeO2F4 octahedra that share corners with four equivalent Fe(4)O3F3 octahedra, corners with four equivalent Fe(6)O3F3 octahedra, and edges with two equivalent Fe(1)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 46-55°. In the second Fe site, Fe(2) is bonded to one O(5), one O(6), two equivalent O(1), and two equivalent F(5) atoms to form FeO4F2 octahedra that share corners with four equivalent Fe(4)O3F3 octahedra, corners with four equivalent Fe(5)O3F tetrahedra, and edges with two equivalent Fe(2)O4F2 octahedra. The corner-sharing octahedral tilt angles are 54°. In the third Fe site, Fe(3) is bonded to one O(4), two equivalent O(2), one F(2), and two equivalent F(6) atoms to form FeO3F3 octahedra that share corners with four equivalent Fe(6)O3F3 octahedra, corners with two equivalent Fe(5)O3F tetrahedra, edges with two equivalent Fe(3)O3F3 octahedra, and edges with four equivalent Mg(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-60°. In the fourth Fe site, Fe(4) is bonded to one O(1), two equivalent O(6), one F(4), and two equivalent F(1) atoms to form FeO3F3 octahedra that share corners with four equivalent Fe(1)O2F4 octahedra, corners with four equivalent Fe(2)O4F2 octahedra, and edges with two equivalent Fe(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-54°. In the fifth Fe site, Fe(5) is bonded to one O(2), two equivalent O(5), and one F(5) atom to form FeO3F tetrahedra that share  a cornercorner with one Mg(1)O3F3 octahedra, corners with two equivalent Fe(3)O3F3 octahedra, corners with four equivalent Fe(2)O4F2 octahedra, and corners with two equivalent Fe(5)O3F tetrahedra. The corner-sharing octahedral tilt angles range from 48-58°. In the sixth Fe site, Fe(6) is bonded to one O(3), two equivalent O(4), one F(6), and two equivalent F(3) atoms to form distorted FeO3F3 octahedra that share corners with two equivalent Mg(1)O3F3 octahedra, corners with four equivalent Fe(1)O2F4 octahedra, corners with four equivalent Fe(3)O3F3 octahedra, edges with two equivalent Fe(6)O3F3 octahedra, and  a faceface with one Mg(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 30-60°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(4) and two equivalent Fe(2) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(5), and two equivalent Fe(3) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(6) and two equivalent Fe(1) atoms. In the fourth O site, O(4) is bonded to two equivalent Mg(1), one Fe(3), and two equivalent Fe(6) atoms to form distorted edge-sharing OMg2Fe3 trigonal bipyramids. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(5) atoms. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(4) atoms. There are six inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Fe(1) and two equivalent Fe(4) atoms. In the second F site, F(2) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Mg(1) and one Fe(3) atom. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one Fe(1) and two equivalent Fe(6) atoms. In the fourth F site, F(4) is bonded in a distorted T-shaped geometry to one Fe(4) and two equivalent Fe(1) atoms. In the fifth F site, F(5) is bonded in a distorted T-shaped geometry to one Fe(5) and two equivalent Fe(2) atoms. In the sixth F site, F(6) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(6), and two equivalent Fe(3) atoms.
MgFe6(OF)6 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), two equivalent O(4), one F(6), and two equivalent F(2) atoms to form MgO3F3 octahedra that share corners with two equivalent Fe(6)O3F3 octahedra,  a cornercorner with one Fe(5)O3F tetrahedra, edges with two equivalent Mg(1)O3F3 octahedra, edges with four equivalent Fe(3)O3F3 octahedra, and  a faceface with one Fe(6)O3F3 octahedra. The corner-sharing octahedral tilt angles are 30°. The Mg(1)-O(2) bond length is 1.99 Å. There is one shorter (2.16 Å) and one longer (2.18 Å) Mg(1)-O(4) bond length. The Mg(1)-F(6) bond length is 2.02 Å. There is one shorter (2.00 Å) and one longer (2.01 Å) Mg(1)-F(2) bond length. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(3), one F(1), one F(3), and two equivalent F(4) atoms to form FeO2F4 octahedra that share corners with four equivalent Fe(4)O3F3 octahedra, corners with four equivalent Fe(6)O3F3 octahedra, and edges with two equivalent Fe(1)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 46-55°. Both Fe(1)-O(3) bond lengths are 1.92 Å. The Fe(1)-F(1) bond length is 2.14 Å. The Fe(1)-F(3) bond length is 1.98 Å. Both Fe(1)-F(4) bond lengths are 2.17 Å. In the second Fe site, Fe(2) is bonded to one O(5), one O(6), two equivalent O(1), and two equivalent F(5) atoms to form FeO4F2 octahedra that share corners with four equivalent Fe(4)O3F3 octahedra, corners with four equivalent Fe(5)O3F tetrahedra, and edges with two equivalent Fe(2)O4F2 octahedra. The corner-sharing octahedral tilt angles are 54°. The Fe(2)-O(5) bond length is 2.02 Å. The Fe(2)-O(6) bond length is 2.00 Å. Both Fe(2)-O(1) bond lengths are 1.95 Å. There is one shorter (2.26 Å) and one longer (2.27 Å) Fe(2)-F(5) bond length. In the third Fe site, Fe(3) is bonded to one O(4), two equivalent O(2), one F(2), and two equivalent F(6) atoms to form FeO3F3 octahedra that share corners with four equivalent Fe(6)O3F3 octahedra, corners with two equivalent Fe(5)O3F tetrahedra, edges with two equivalent Fe(3)O3F3 octahedra, and edges with four equivalent Mg(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-60°. The Fe(3)-O(4) bond length is 1.99 Å. There is one shorter (2.17 Å) and one longer (2.18 Å) Fe(3)-O(2) bond length. The Fe(3)-F(2) bond length is 2.10 Å. Both Fe(3)-F(6) bond lengths are 2.17 Å. In the fourth Fe site, Fe(4) is bonded to one O(1), two equivalent O(6), one F(4), and two equivalent F(1) atoms to form FeO3F3 octahedra that share corners with four equivalent Fe(1)O2F4 octahedra, corners with four equivalent Fe(2)O4F2 octahedra, and edges with two equivalent Fe(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-54°. The Fe(4)-O(1) bond length is 1.98 Å. Both Fe(4)-O(6) bond lengths are 1.95 Å. The Fe(4)-F(4) bond length is 2.17 Å. Both Fe(4)-F(1) bond lengths are 2.16 Å. In the fifth Fe site, Fe(5) is bonded to one O(2), two equivalent O(5), and one F(5) atom to form FeO3F tetrahedra that share  a cornercorner with one Mg(1)O3F3 octahedra, corners with two equivalent Fe(3)O3F3 octahedra, corners with four equivalent Fe(2)O4F2 octahedra, and corners with two equivalent Fe(5)O3F tetrahedra. The corner-sharing octahedral tilt angles range from 48-58°. The Fe(5)-O(2) bond length is 1.84 Å. Both Fe(5)-O(5) bond lengths are 1.89 Å. The Fe(5)-F(5) bond length is 2.02 Å. In the sixth Fe site, Fe(6) is bonded to one O(3), two equivalent O(4), one F(6), and two equivalent F(3) atoms to form distorted FeO3F3 octahedra that share corners with two equivalent Mg(1)O3F3 octahedra, corners with four equivalent Fe(1)O2F4 octahedra, corners with four equivalent Fe(3)O3F3 octahedra, edges with two equivalent Fe(6)O3F3 octahedra, and  a faceface with one Mg(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 30-60°. The Fe(6)-O(3) bond length is 2.04 Å. Both Fe(6)-O(4) bond lengths are 2.16 Å. The Fe(6)-F(6) bond length is 2.42 Å. There is one shorter (2.18 Å) and one longer (2.19 Å) Fe(6)-F(3) bond length. There are six inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(4) and two equivalent Fe(2) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(5), and two equivalent Fe(3) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(6) and two equivalent Fe(1) atoms. In the fourth O site, O(4) is bonded to two equivalent Mg(1), one Fe(3), and two equivalent Fe(6) atoms to form distorted edge-sharing OMg2Fe3 trigonal bipyramids. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(5) atoms. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(4) atoms. There are six inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Fe(1) and two equivalent Fe(4) atoms. In the second F site, F(2) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Mg(1) and one Fe(3) atom. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one Fe(1) and two equivalent Fe(6) atoms. In the fourth F site, F(4) is bonded in a distorted T-shaped geometry to one Fe(4) and two equivalent Fe(1) atoms. In the fifth F site, F(5) is bonded in a distorted T-shaped geometry to one Fe(5) and two equivalent Fe(2) atoms. In the sixth F site, F(6) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(6), and two equivalent Fe(3) atoms.