MgFe6(O2F)4 crystallizes in the monoclinic Cm space group. Mg(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), two equivalent O(3), and one F(1) atom. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(5), two equivalent O(3), one F(1), and one F(3) atom to form edge-sharing FeO4F2 octahedra. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(5), one O(6), and two equivalent F(2) atoms to form edge-sharing FeO4F2 octahedra. In the third Fe site, Fe(3) is bonded to one O(2), one O(6), two equivalent O(4), one F(1), and one F(3) atom to form distorted edge-sharing FeO4F2 octahedra. In the fourth Fe site, Fe(4) is bonded in a 5-coordinate geometry to one O(5), two equivalent O(3), and two equivalent F(2) atoms. In the fifth Fe site, Fe(5) is bonded in a 5-coordinate geometry to two equivalent O(3), two equivalent O(4), and one F(3) atom. In the sixth Fe site, Fe(6) is bonded in a 5-coordinate geometry to one O(2), two equivalent O(4), and two equivalent F(2) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a T-shaped geometry to one Mg(1), one Fe(1), and one Fe(2) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Fe(2), one Fe(3), and one Fe(6) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(4), and one Fe(5) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(5), and one Fe(6) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(2), and one Fe(4) atom. In the sixth O site, O(6) is bonded in an L-shaped geometry to one Fe(2) and one Fe(3) atom. There are three inequivalent F sites. In the first F site, F(3) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(3), and one Fe(5) atom. In the second F site, F(1) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(1), and one Fe(3) atom. In the third F site, F(2) is bonded in a trigonal planar geometry to one Fe(2), one Fe(4), and one Fe(6) atom.
MgFe6(O2F)4 crystallizes in the monoclinic Cm space group. Mg(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), two equivalent O(3), and one F(1) atom. The Mg(1)-O(1) bond length is 1.90 Å. Both Mg(1)-O(3) bond lengths are 2.00 Å. The Mg(1)-F(1) bond length is 1.92 Å. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(5), two equivalent O(3), one F(1), and one F(3) atom to form edge-sharing FeO4F2 octahedra. The Fe(1)-O(1) bond length is 1.93 Å. The Fe(1)-O(5) bond length is 1.91 Å. Both Fe(1)-O(3) bond lengths are 2.07 Å. The Fe(1)-F(1) bond length is 2.17 Å. The Fe(1)-F(3) bond length is 2.06 Å. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(5), one O(6), and two equivalent F(2) atoms to form edge-sharing FeO4F2 octahedra. The Fe(2)-O(1) bond length is 1.95 Å. The Fe(2)-O(2) bond length is 2.04 Å. The Fe(2)-O(5) bond length is 2.18 Å. The Fe(2)-O(6) bond length is 1.88 Å. Both Fe(2)-F(2) bond lengths are 2.10 Å. In the third Fe site, Fe(3) is bonded to one O(2), one O(6), two equivalent O(4), one F(1), and one F(3) atom to form distorted edge-sharing FeO4F2 octahedra. The Fe(3)-O(2) bond length is 1.99 Å. The Fe(3)-O(6) bond length is 1.86 Å. Both Fe(3)-O(4) bond lengths are 2.02 Å. The Fe(3)-F(1) bond length is 2.14 Å. The Fe(3)-F(3) bond length is 2.52 Å. In the fourth Fe site, Fe(4) is bonded in a 5-coordinate geometry to one O(5), two equivalent O(3), and two equivalent F(2) atoms. The Fe(4)-O(5) bond length is 1.83 Å. Both Fe(4)-O(3) bond lengths are 2.06 Å. Both Fe(4)-F(2) bond lengths are 2.05 Å. In the fifth Fe site, Fe(5) is bonded in a 5-coordinate geometry to two equivalent O(3), two equivalent O(4), and one F(3) atom. Both Fe(5)-O(3) bond lengths are 2.13 Å. Both Fe(5)-O(4) bond lengths are 1.92 Å. The Fe(5)-F(3) bond length is 1.97 Å. In the sixth Fe site, Fe(6) is bonded in a 5-coordinate geometry to one O(2), two equivalent O(4), and two equivalent F(2) atoms. The Fe(6)-O(2) bond length is 1.89 Å. Both Fe(6)-O(4) bond lengths are 1.96 Å. Both Fe(6)-F(2) bond lengths are 2.20 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a T-shaped geometry to one Mg(1), one Fe(1), and one Fe(2) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Fe(2), one Fe(3), and one Fe(6) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(4), and one Fe(5) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(5), and one Fe(6) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(2), and one Fe(4) atom. In the sixth O site, O(6) is bonded in an L-shaped geometry to one Fe(2) and one Fe(3) atom. There are three inequivalent F sites. In the first F site, F(3) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(3), and one Fe(5) atom. In the second F site, F(1) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(1), and one Fe(3) atom. In the third F site, F(2) is bonded in a trigonal planar geometry to one Fe(2), one Fe(4), and one Fe(6) atom.