MgFe6(OF)6 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(4), one O(6), one F(1), one F(2), and one F(5) atom to form MgO3F3 octahedra that share corners with two equivalent Fe(4)O3F3 octahedra,  a cornercorner with one Fe(6)O3F2 trigonal bipyramid, and  an edgeedge with one Fe(6)O3F2 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 42-47°. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(3), one O(5), one F(3), one F(4), and one F(6) atom to form distorted FeO3F3 octahedra that share corners with four equivalent Fe(4)O3F3 octahedra and corners with two equivalent Fe(6)O3F2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 37-50°. In the second Fe site, Fe(2) is bonded in a 5-coordinate geometry to one O(4), one O(5), one O(6), one F(1), one F(2), and one F(3) atom. In the third Fe site, Fe(3) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(4), one F(2), and one F(4) atom. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(2), one O(6), one F(3), one F(4), and one F(6) atom to form FeO3F3 octahedra that share corners with two equivalent Mg(1)O3F3 octahedra, corners with four equivalent Fe(1)O3F3 octahedra, and  an edgeedge with one Fe(6)O3F2 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 37-50°. In the fifth Fe site, Fe(5) is bonded in a 5-coordinate geometry to one O(1), one O(3), one F(1), one F(5), and one F(6) atom. In the sixth Fe site, Fe(6) is bonded to one O(2), one O(5), one O(6), one F(1), and one F(5) atom to form distorted FeO3F2 trigonal bipyramids that share  a cornercorner with one Mg(1)O3F3 octahedra, corners with two equivalent Fe(1)O3F3 octahedra,  an edgeedge with one Mg(1)O3F3 octahedra, and  an edgeedge with one Fe(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a see-saw-like geometry to one Mg(1), one Fe(3), one Fe(4), and one Fe(5) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(4), and one Fe(6) atom. In the third O site, O(3) is bonded in a 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 non-coplanar geometry to one Mg(1), one Fe(2), and one Fe(3) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(6) atom. In the sixth O site, O(6) is bonded in a distorted trigonal pyramidal geometry to one Mg(1), one Fe(2), one Fe(4), and one Fe(6) atom. There are six inequivalent F sites. In the first F site, F(1) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(2), one Fe(5), and one Fe(6) atom. In the second F site, F(2) is bonded in a 3-coordinate geometry to one Mg(1), one Fe(2), and one Fe(3) atom. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(2), and one Fe(4) atom. In the fourth F site, F(4) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(3), and one Fe(4) atom. In the fifth F site, F(5) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Fe(5), and one Fe(6) atom. In the sixth F site, F(6) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(4), and one Fe(5) atom.
MgFe6(OF)6 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(4), one O(6), one F(1), one F(2), and one F(5) atom to form MgO3F3 octahedra that share corners with two equivalent Fe(4)O3F3 octahedra,  a cornercorner with one Fe(6)O3F2 trigonal bipyramid, and  an edgeedge with one Fe(6)O3F2 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 42-47°. The Mg(1)-O(1) bond length is 2.07 Å. The Mg(1)-O(4) bond length is 1.96 Å. The Mg(1)-O(6) bond length is 2.28 Å. The Mg(1)-F(1) bond length is 2.08 Å. The Mg(1)-F(2) bond length is 1.96 Å. The Mg(1)-F(5) bond length is 2.04 Å. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(3), one O(5), one F(3), one F(4), and one F(6) atom to form distorted FeO3F3 octahedra that share corners with four equivalent Fe(4)O3F3 octahedra and corners with two equivalent Fe(6)O3F2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 37-50°. The Fe(1)-O(2) bond length is 1.98 Å. The Fe(1)-O(3) bond length is 1.87 Å. The Fe(1)-O(5) bond length is 1.96 Å. The Fe(1)-F(3) bond length is 2.10 Å. The Fe(1)-F(4) bond length is 2.10 Å. The Fe(1)-F(6) bond length is 2.35 Å. In the second Fe site, Fe(2) is bonded in a 5-coordinate geometry to one O(4), one O(5), one O(6), one F(1), one F(2), and one F(3) atom. The Fe(2)-O(4) bond length is 1.87 Å. The Fe(2)-O(5) bond length is 1.95 Å. The Fe(2)-O(6) bond length is 1.97 Å. The Fe(2)-F(1) bond length is 2.61 Å. The Fe(2)-F(2) bond length is 2.02 Å. The Fe(2)-F(3) bond length is 2.16 Å. In the third Fe site, Fe(3) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(4), one F(2), and one F(4) atom. The Fe(3)-O(1) bond length is 2.11 Å. The Fe(3)-O(3) bond length is 1.99 Å. The Fe(3)-O(4) bond length is 1.97 Å. The Fe(3)-F(2) bond length is 2.33 Å. The Fe(3)-F(4) bond length is 2.19 Å. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(2), one O(6), one F(3), one F(4), and one F(6) atom to form FeO3F3 octahedra that share corners with two equivalent Mg(1)O3F3 octahedra, corners with four equivalent Fe(1)O3F3 octahedra, and  an edgeedge with one Fe(6)O3F2 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 37-50°. The Fe(4)-O(1) bond length is 1.93 Å. The Fe(4)-O(2) bond length is 1.99 Å. The Fe(4)-O(6) bond length is 2.07 Å. The Fe(4)-F(3) bond length is 2.27 Å. The Fe(4)-F(4) bond length is 2.10 Å. The Fe(4)-F(6) bond length is 2.07 Å. In the fifth Fe site, Fe(5) is bonded in a 5-coordinate geometry to one O(1), one O(3), one F(1), one F(5), and one F(6) atom. The Fe(5)-O(1) bond length is 2.06 Å. The Fe(5)-O(3) bond length is 1.95 Å. The Fe(5)-F(1) bond length is 2.33 Å. The Fe(5)-F(5) bond length is 2.15 Å. The Fe(5)-F(6) bond length is 2.15 Å. In the sixth Fe site, Fe(6) is bonded to one O(2), one O(5), one O(6), one F(1), and one F(5) atom to form distorted FeO3F2 trigonal bipyramids that share  a cornercorner with one Mg(1)O3F3 octahedra, corners with two equivalent Fe(1)O3F3 octahedra,  an edgeedge with one Mg(1)O3F3 octahedra, and  an edgeedge with one Fe(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. The Fe(6)-O(2) bond length is 1.92 Å. The Fe(6)-O(5) bond length is 1.90 Å. The Fe(6)-O(6) bond length is 2.00 Å. The Fe(6)-F(1) bond length is 2.07 Å. The Fe(6)-F(5) bond length is 2.08 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a see-saw-like geometry to one Mg(1), one Fe(3), one Fe(4), and one Fe(5) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(4), and one Fe(6) atom. In the third O site, O(3) is bonded in a 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 non-coplanar geometry to one Mg(1), one Fe(2), and one Fe(3) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(6) atom. In the sixth O site, O(6) is bonded in a distorted trigonal pyramidal geometry to one Mg(1), one Fe(2), one Fe(4), and one Fe(6) atom. There are six inequivalent F sites. In the first F site, F(1) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(2), one Fe(5), and one Fe(6) atom. In the second F site, F(2) is bonded in a 3-coordinate geometry to one Mg(1), one Fe(2), and one Fe(3) atom. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(2), and one Fe(4) atom. In the fourth F site, F(4) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(3), and one Fe(4) atom. In the fifth F site, F(5) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Fe(5), and one Fe(6) atom. In the sixth F site, F(6) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(4), and one Fe(5) atom.