MgFe6(OF)6 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(6), one F(2), one F(3), one F(5), and one F(6) atom to form MgO2F4 octahedra that share  a cornercorner with one Fe(6)O3F3 octahedra, corners with two equivalent Fe(5)O2F4 octahedra,  a cornercorner with one Fe(1)O4F square pyramid, edges with two equivalent Fe(2)O3F3 octahedra,  an edgeedge with one Fe(1)O4F square pyramid, and  a faceface with one Fe(6)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 40-55°. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), one O(4), one O(6), and one F(3) atom to form distorted FeO4F square pyramids that share  a cornercorner with one Mg(1)O2F4 octahedra,  a cornercorner with one Fe(5)O2F4 octahedra, corners with two equivalent Fe(6)O3F3 octahedra,  an edgeedge with one Mg(1)O2F4 octahedra,  an edgeedge with one Fe(2)O3F3 octahedra, and  an edgeedge with one Fe(3)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 32-75°. In the second Fe site, Fe(2) is bonded to one O(2), one O(5), one O(6), one F(2), one F(3), and one F(6) atom to form FeO3F3 octahedra that share corners with two equivalent Fe(5)O2F4 octahedra, corners with four equivalent Fe(6)O3F3 octahedra,  an edgeedge with one Fe(3)O4F2 octahedra, edges with two equivalent Mg(1)O2F4 octahedra, and  an edgeedge with one Fe(1)O4F square pyramid. The corner-sharing octahedral tilt angles range from 42-56°. In the third Fe site, Fe(3) is bonded to one O(2), one O(3), one O(4), one O(5), one F(1), and one F(4) atom to form FeO4F2 octahedra that share corners with two equivalent Fe(6)O3F3 octahedra, corners with four equivalent Fe(5)O2F4 octahedra,  an edgeedge with one Fe(2)O3F3 octahedra, and  an edgeedge with one Fe(1)O4F square pyramid. The corner-sharing octahedral tilt angles range from 36-55°. In the fourth Fe site, Fe(4) is bonded in a 5-coordinate geometry to one O(1), one O(4), one F(1), one F(3), and one F(5) atom. In the fifth Fe site, Fe(5) is bonded to one O(3), one O(5), one F(1), one F(2), one F(4), and one F(5) atom to form FeO2F4 octahedra that share corners with two equivalent Mg(1)O2F4 octahedra, corners with two equivalent Fe(2)O3F3 octahedra, corners with four equivalent Fe(3)O4F2 octahedra,  a cornercorner with one Fe(1)O4F square pyramid, and  an edgeedge with one Fe(6)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 36-54°. In the sixth Fe site, Fe(6) is bonded to one O(1), one O(2), one O(6), one F(2), one F(4), and one F(6) atom to form FeO3F3 octahedra that share  a cornercorner with one Mg(1)O2F4 octahedra, corners with two equivalent Fe(3)O4F2 octahedra, corners with four equivalent Fe(2)O3F3 octahedra, corners with two equivalent Fe(1)O4F square pyramids,  an edgeedge with one Fe(5)O2F4 octahedra, and  a faceface with one Mg(1)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 42-56°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to one Mg(1), one Fe(1), one Fe(4), and one Fe(6) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(6) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(5) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(4) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(5) atom. In the sixth O site, O(6) is bonded to one Mg(1), one Fe(1), one Fe(2), and one Fe(6) atom to form distorted OMgFe3 trigonal pyramids that share  a cornercorner with one F(3)MgFe3 trigonal pyramid and  an edgeedge with one F(3)MgFe3 trigonal pyramid. There are six inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(4), and one Fe(5) atom. In the second F site, F(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(5), and one Fe(6) atom. In the third F site, F(3) is bonded to one Mg(1), one Fe(1), one Fe(2), and one Fe(4) atom to form distorted FMgFe3 trigonal pyramids that share  a cornercorner with one O(6)MgFe3 trigonal pyramid and  an edgeedge with one O(6)MgFe3 trigonal pyramid. In the fourth F site, F(4) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(5), and one Fe(6) atom. In the fifth F site, F(5) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(4), and one Fe(5) atom. In the sixth F site, F(6) is bonded in a distorted trigonal planar geometry to one Mg(1), one Fe(2), and one Fe(6) atom.
MgFe6(OF)6 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(6), one F(2), one F(3), one F(5), and one F(6) atom to form MgO2F4 octahedra that share  a cornercorner with one Fe(6)O3F3 octahedra, corners with two equivalent Fe(5)O2F4 octahedra,  a cornercorner with one Fe(1)O4F square pyramid, edges with two equivalent Fe(2)O3F3 octahedra,  an edgeedge with one Fe(1)O4F square pyramid, and  a faceface with one Fe(6)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 40-55°. The Mg(1)-O(1) bond length is 2.03 Å. The Mg(1)-O(6) bond length is 1.98 Å. The Mg(1)-F(2) bond length is 2.23 Å. The Mg(1)-F(3) bond length is 1.98 Å. The Mg(1)-F(5) bond length is 1.99 Å. The Mg(1)-F(6) bond length is 2.00 Å. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), one O(4), one O(6), and one F(3) atom to form distorted FeO4F square pyramids that share  a cornercorner with one Mg(1)O2F4 octahedra,  a cornercorner with one Fe(5)O2F4 octahedra, corners with two equivalent Fe(6)O3F3 octahedra,  an edgeedge with one Mg(1)O2F4 octahedra,  an edgeedge with one Fe(2)O3F3 octahedra, and  an edgeedge with one Fe(3)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 32-75°. The Fe(1)-O(1) bond length is 1.90 Å. The Fe(1)-O(3) bond length is 2.04 Å. The Fe(1)-O(4) bond length is 1.89 Å. The Fe(1)-O(6) bond length is 2.00 Å. The Fe(1)-F(3) bond length is 2.35 Å. In the second Fe site, Fe(2) is bonded to one O(2), one O(5), one O(6), one F(2), one F(3), and one F(6) atom to form FeO3F3 octahedra that share corners with two equivalent Fe(5)O2F4 octahedra, corners with four equivalent Fe(6)O3F3 octahedra,  an edgeedge with one Fe(3)O4F2 octahedra, edges with two equivalent Mg(1)O2F4 octahedra, and  an edgeedge with one Fe(1)O4F square pyramid. The corner-sharing octahedral tilt angles range from 42-56°. The Fe(2)-O(2) bond length is 1.92 Å. The Fe(2)-O(5) bond length is 1.90 Å. The Fe(2)-O(6) bond length is 2.01 Å. The Fe(2)-F(2) bond length is 2.23 Å. The Fe(2)-F(3) bond length is 2.22 Å. The Fe(2)-F(6) bond length is 2.13 Å. In the third Fe site, Fe(3) is bonded to one O(2), one O(3), one O(4), one O(5), one F(1), and one F(4) atom to form FeO4F2 octahedra that share corners with two equivalent Fe(6)O3F3 octahedra, corners with four equivalent Fe(5)O2F4 octahedra,  an edgeedge with one Fe(2)O3F3 octahedra, and  an edgeedge with one Fe(1)O4F square pyramid. The corner-sharing octahedral tilt angles range from 36-55°. The Fe(3)-O(2) bond length is 1.94 Å. The Fe(3)-O(3) bond length is 2.02 Å. The Fe(3)-O(4) bond length is 1.96 Å. The Fe(3)-O(5) bond length is 2.06 Å. The Fe(3)-F(1) bond length is 2.31 Å. The Fe(3)-F(4) bond length is 2.18 Å. In the fourth Fe site, Fe(4) is bonded in a 5-coordinate geometry to one O(1), one O(4), one F(1), one F(3), and one F(5) atom. The Fe(4)-O(1) bond length is 1.96 Å. The Fe(4)-O(4) bond length is 1.95 Å. The Fe(4)-F(1) bond length is 2.04 Å. The Fe(4)-F(3) bond length is 2.26 Å. The Fe(4)-F(5) bond length is 2.36 Å. In the fifth Fe site, Fe(5) is bonded to one O(3), one O(5), one F(1), one F(2), one F(4), and one F(5) atom to form FeO2F4 octahedra that share corners with two equivalent Mg(1)O2F4 octahedra, corners with two equivalent Fe(2)O3F3 octahedra, corners with four equivalent Fe(3)O4F2 octahedra,  a cornercorner with one Fe(1)O4F square pyramid, and  an edgeedge with one Fe(6)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 36-54°. The Fe(5)-O(3) bond length is 1.92 Å. The Fe(5)-O(5) bond length is 1.95 Å. The Fe(5)-F(1) bond length is 2.04 Å. The Fe(5)-F(2) bond length is 2.19 Å. The Fe(5)-F(4) bond length is 2.11 Å. The Fe(5)-F(5) bond length is 2.03 Å. In the sixth Fe site, Fe(6) is bonded to one O(1), one O(2), one O(6), one F(2), one F(4), and one F(6) atom to form FeO3F3 octahedra that share  a cornercorner with one Mg(1)O2F4 octahedra, corners with two equivalent Fe(3)O4F2 octahedra, corners with four equivalent Fe(2)O3F3 octahedra, corners with two equivalent Fe(1)O4F square pyramids,  an edgeedge with one Fe(5)O2F4 octahedra, and  a faceface with one Mg(1)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 42-56°. The Fe(6)-O(1) bond length is 2.16 Å. The Fe(6)-O(2) bond length is 2.00 Å. The Fe(6)-O(6) bond length is 2.23 Å. The Fe(6)-F(2) bond length is 2.35 Å. The Fe(6)-F(4) bond length is 2.17 Å. The Fe(6)-F(6) bond length is 2.15 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to one Mg(1), one Fe(1), one Fe(4), and one Fe(6) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(6) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(5) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(4) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(5) atom. In the sixth O site, O(6) is bonded to one Mg(1), one Fe(1), one Fe(2), and one Fe(6) atom to form distorted OMgFe3 trigonal pyramids that share  a cornercorner with one F(3)MgFe3 trigonal pyramid and  an edgeedge with one F(3)MgFe3 trigonal pyramid. There are six inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(4), and one Fe(5) atom. In the second F site, F(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(5), and one Fe(6) atom. In the third F site, F(3) is bonded to one Mg(1), one Fe(1), one Fe(2), and one Fe(4) atom to form distorted FMgFe3 trigonal pyramids that share  a cornercorner with one O(6)MgFe3 trigonal pyramid and  an edgeedge with one O(6)MgFe3 trigonal pyramid. In the fourth F site, F(4) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(5), and one Fe(6) atom. In the fifth F site, F(5) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(4), and one Fe(5) atom. In the sixth F site, F(6) is bonded in a distorted trigonal planar geometry to one Mg(1), one Fe(2), and one Fe(6) atom.