MgFe6(OF)6 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(5), one O(6), one F(1), one F(2), and one F(3) atom to form distorted MgO2F3 trigonal bipyramids that share  a cornercorner with one Fe(2)O3F2 trigonal bipyramid,  a cornercorner with one Fe(5)O3F2 trigonal bipyramid, corners with two equivalent Fe(1)O3F2 trigonal bipyramids, corners with two equivalent Fe(6)O3F2 trigonal bipyramids, and  an edgeedge with one Fe(2)O3F2 trigonal bipyramid. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(4), one O(6), one F(1), and one F(5) atom to form distorted FeO3F2 trigonal bipyramids that share corners with two equivalent Mg(1)O2F3 trigonal bipyramids, corners with two equivalent Fe(5)O3F2 trigonal bipyramids,  an edgeedge with one Fe(2)O3F2 trigonal bipyramid, and  an edgeedge with one Fe(3)O3F2 trigonal bipyramid. In the second Fe site, Fe(2) is bonded to one O(1), one O(5), one O(6), one F(1), and one F(6) atom to form distorted FeO3F2 trigonal bipyramids that share  a cornercorner with one Mg(1)O2F3 trigonal bipyramid, corners with two equivalent Fe(6)O3F2 trigonal bipyramids,  an edgeedge with one Mg(1)O2F3 trigonal bipyramid,  an edgeedge with one Fe(1)O3F2 trigonal bipyramid, and  an edgeedge with one Fe(3)O3F2 trigonal bipyramid. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), one O(3), one F(5), and one F(6) atom to form a mixture of distorted corner and edge-sharing FeO3F2 trigonal bipyramids. In the fourth Fe site, Fe(4) is bonded in a 6-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 fifth Fe site, Fe(5) is bonded to one O(2), one O(3), one O(4), one F(2), and one F(4) atom to form distorted FeO3F2 trigonal bipyramids that share  a cornercorner with one Mg(1)O2F3 trigonal bipyramid, corners with two equivalent Fe(1)O3F2 trigonal bipyramids, corners with two equivalent Fe(3)O3F2 trigonal bipyramids, and  an edgeedge with one Fe(6)O3F2 trigonal bipyramid. In the sixth Fe site, Fe(6) is bonded to one O(1), one O(3), one O(5), one F(3), and one F(4) atom to form distorted FeO3F2 trigonal bipyramids that share corners with two equivalent Mg(1)O2F3 trigonal bipyramids, corners with two equivalent Fe(2)O3F2 trigonal bipyramids, corners with two equivalent Fe(3)O3F2 trigonal bipyramids, and  an edgeedge with one Fe(5)O3F2 trigonal bipyramid. There are six inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(6) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(5) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(5), and one Fe(6) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(4), and one Fe(5) atom. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(4), and one Fe(6) atom. In the sixth O site, O(6) is bonded in a distorted tetrahedral geometry to one Mg(1), one Fe(1), one Fe(2), and one Fe(4) 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(1), one Fe(2), and one Fe(4) atom. In the second F site, F(2) is bonded in a T-shaped geometry to one Mg(1), one Fe(4), and one Fe(5) atom. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(4), and one Fe(6) atom. In the fourth F site, F(4) is bonded in an L-shaped geometry to one Fe(5) and one Fe(6) atom. In the fifth F site, F(5) is bonded in a distorted water-like geometry to one Fe(1) and one Fe(3) atom. In the sixth F site, F(6) is bonded in a distorted water-like geometry to one Fe(2) and one Fe(3) atom.
MgFe6(OF)6 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(5), one O(6), one F(1), one F(2), and one F(3) atom to form distorted MgO2F3 trigonal bipyramids that share  a cornercorner with one Fe(2)O3F2 trigonal bipyramid,  a cornercorner with one Fe(5)O3F2 trigonal bipyramid, corners with two equivalent Fe(1)O3F2 trigonal bipyramids, corners with two equivalent Fe(6)O3F2 trigonal bipyramids, and  an edgeedge with one Fe(2)O3F2 trigonal bipyramid. The Mg(1)-O(5) bond length is 2.09 Å. The Mg(1)-O(6) bond length is 1.97 Å. The Mg(1)-F(1) bond length is 1.94 Å. The Mg(1)-F(2) bond length is 2.15 Å. The Mg(1)-F(3) bond length is 1.94 Å. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(4), one O(6), one F(1), and one F(5) atom to form distorted FeO3F2 trigonal bipyramids that share corners with two equivalent Mg(1)O2F3 trigonal bipyramids, corners with two equivalent Fe(5)O3F2 trigonal bipyramids,  an edgeedge with one Fe(2)O3F2 trigonal bipyramid, and  an edgeedge with one Fe(3)O3F2 trigonal bipyramid. The Fe(1)-O(2) bond length is 1.95 Å. The Fe(1)-O(4) bond length is 1.90 Å. The Fe(1)-O(6) bond length is 1.94 Å. The Fe(1)-F(1) bond length is 2.18 Å. The Fe(1)-F(5) bond length is 1.98 Å. In the second Fe site, Fe(2) is bonded to one O(1), one O(5), one O(6), one F(1), and one F(6) atom to form distorted FeO3F2 trigonal bipyramids that share  a cornercorner with one Mg(1)O2F3 trigonal bipyramid, corners with two equivalent Fe(6)O3F2 trigonal bipyramids,  an edgeedge with one Mg(1)O2F3 trigonal bipyramid,  an edgeedge with one Fe(1)O3F2 trigonal bipyramid, and  an edgeedge with one Fe(3)O3F2 trigonal bipyramid. The Fe(2)-O(1) bond length is 2.07 Å. The Fe(2)-O(5) bond length is 2.05 Å. The Fe(2)-O(6) bond length is 2.12 Å. The Fe(2)-F(1) bond length is 2.28 Å. The Fe(2)-F(6) bond length is 2.07 Å. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), one O(3), one F(5), and one F(6) atom to form a mixture of distorted corner and edge-sharing FeO3F2 trigonal bipyramids. The Fe(3)-O(1) bond length is 1.94 Å. The Fe(3)-O(2) bond length is 1.98 Å. The Fe(3)-O(3) bond length is 1.92 Å. The Fe(3)-F(5) bond length is 2.13 Å. The Fe(3)-F(6) bond length is 2.02 Å. In the fourth Fe site, Fe(4) is bonded in a 6-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(4)-O(4) bond length is 2.01 Å. The Fe(4)-O(5) bond length is 2.05 Å. The Fe(4)-O(6) bond length is 2.09 Å. The Fe(4)-F(1) bond length is 2.49 Å. The Fe(4)-F(2) bond length is 2.12 Å. The Fe(4)-F(3) bond length is 2.14 Å. In the fifth Fe site, Fe(5) is bonded to one O(2), one O(3), one O(4), one F(2), and one F(4) atom to form distorted FeO3F2 trigonal bipyramids that share  a cornercorner with one Mg(1)O2F3 trigonal bipyramid, corners with two equivalent Fe(1)O3F2 trigonal bipyramids, corners with two equivalent Fe(3)O3F2 trigonal bipyramids, and  an edgeedge with one Fe(6)O3F2 trigonal bipyramid. The Fe(5)-O(2) bond length is 1.93 Å. The Fe(5)-O(3) bond length is 1.97 Å. The Fe(5)-O(4) bond length is 1.96 Å. The Fe(5)-F(2) bond length is 2.09 Å. The Fe(5)-F(4) bond length is 2.00 Å. In the sixth Fe site, Fe(6) is bonded to one O(1), one O(3), one O(5), one F(3), and one F(4) atom to form distorted FeO3F2 trigonal bipyramids that share corners with two equivalent Mg(1)O2F3 trigonal bipyramids, corners with two equivalent Fe(2)O3F2 trigonal bipyramids, corners with two equivalent Fe(3)O3F2 trigonal bipyramids, and  an edgeedge with one Fe(5)O3F2 trigonal bipyramid. The Fe(6)-O(1) bond length is 1.92 Å. The Fe(6)-O(3) bond length is 2.00 Å. The Fe(6)-O(5) bond length is 1.95 Å. The Fe(6)-F(3) bond length is 2.11 Å. The Fe(6)-F(4) bond length is 1.99 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(6) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(5) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(5), and one Fe(6) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(4), and one Fe(5) atom. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(4), and one Fe(6) atom. In the sixth O site, O(6) is bonded in a distorted tetrahedral geometry to one Mg(1), one Fe(1), one Fe(2), and one Fe(4) 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(1), one Fe(2), and one Fe(4) atom. In the second F site, F(2) is bonded in a T-shaped geometry to one Mg(1), one Fe(4), and one Fe(5) atom. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(4), and one Fe(6) atom. In the fourth F site, F(4) is bonded in an L-shaped geometry to one Fe(5) and one Fe(6) atom. In the fifth F site, F(5) is bonded in a distorted water-like geometry to one Fe(1) and one Fe(3) atom. In the sixth F site, F(6) is bonded in a distorted water-like geometry to one Fe(2) and one Fe(3) atom.