MgFe8(O7F)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(11), one O(12), one O(13), one O(14), one O(8), and one F(1) atom to form MgO5F octahedra that share  a cornercorner with one Fe(1)O5F octahedra,  a cornercorner with one Fe(2)O5F octahedra,  a cornercorner with one Fe(8)O5F octahedra,  a cornercorner with one Fe(7)O6 octahedra,  a cornercorner with one Fe(4)O5 square pyramid,  a cornercorner with one Fe(5)O5 square pyramid,  an edgeedge with one Fe(3)O5F octahedra,  a faceface with one Fe(8)O5F octahedra, and  a faceface with one Fe(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-52°. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(10), one O(2), one O(3), one O(5), and one F(1) atom to form FeO5F octahedra that share  a cornercorner with one Mg(1)O5F octahedra, corners with two equivalent Fe(3)O5F octahedra,  a cornercorner with one Fe(4)O5 square pyramid, corners with two equivalent Fe(5)O5 square pyramids,  an edgeedge with one Fe(2)O5F octahedra, and  an edgeedge with one Fe(8)O5F octahedra. The corner-sharing octahedral tilt angles range from 43-51°. In the second Fe site, Fe(2) is bonded to one O(10), one O(12), one O(3), one O(4), one O(7), and one F(2) atom to form FeO5F octahedra that share  a cornercorner with one Mg(1)O5F octahedra, corners with two equivalent Fe(3)O5F octahedra,  a cornercorner with one Fe(5)O5 square pyramid, corners with two equivalent Fe(4)O5 square pyramids,  an edgeedge with one Fe(1)O5F octahedra, and  an edgeedge with one Fe(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-51°. In the third Fe site, Fe(3) is bonded to one O(1), one O(11), one O(4), one O(5), one O(8), and one F(2) atom to form distorted FeO5F octahedra that share corners with two equivalent Fe(1)O5F octahedra, corners with two equivalent Fe(2)O5F octahedra, corners with two equivalent Fe(8)O5F octahedra, corners with two equivalent Fe(7)O6 octahedra,  an edgeedge with one Mg(1)O5F octahedra, and  an edgeedge with one Fe(5)O5 square pyramid. The corner-sharing octahedral tilt angles range from 35-61°. In the fourth Fe site, Fe(4) is bonded to one O(10), one O(14), one O(6), one O(7), and one O(9) atom to form distorted FeO5 square pyramids that share  a cornercorner with one Mg(1)O5F octahedra,  a cornercorner with one Fe(1)O5F octahedra,  a cornercorner with one Fe(8)O5F octahedra, corners with two equivalent Fe(2)O5F octahedra, corners with two equivalent Fe(7)O6 octahedra, and  an edgeedge with one Fe(5)O5 square pyramid. The corner-sharing octahedral tilt angles range from 42-69°. In the fifth Fe site, Fe(5) is bonded to one O(3), one O(5), one O(6), one O(8), and one O(9) atom to form FeO5 square pyramids that share  a cornercorner with one Mg(1)O5F octahedra,  a cornercorner with one Fe(2)O5F octahedra,  a cornercorner with one Fe(7)O6 octahedra, corners with two equivalent Fe(1)O5F octahedra, corners with two equivalent Fe(8)O5F octahedra,  an edgeedge with one Fe(3)O5F octahedra, and  an edgeedge with one Fe(4)O5 square pyramid. The corner-sharing octahedral tilt angles range from 46-73°. In the sixth Fe site, Fe(6) is bonded in a 6-coordinate geometry to one O(1), one O(13), one O(14), one O(2), one O(7), and one F(2) atom. In the seventh Fe site, Fe(7) is bonded to one O(11), one O(12), one O(13), one O(14), one O(4), and one O(9) atom to form distorted FeO6 octahedra that share  a cornercorner with one Mg(1)O5F octahedra, corners with two equivalent Fe(3)O5F octahedra,  a cornercorner with one Fe(5)O5 square pyramid, corners with two equivalent Fe(4)O5 square pyramids,  an edgeedge with one Fe(2)O5F octahedra,  an edgeedge with one Fe(8)O5F octahedra, and  a faceface with one Mg(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 35-52°. In the eighth Fe site, Fe(8) is bonded to one O(11), one O(13), one O(2), one O(6), one O(8), and one F(1) atom to form distorted FeO5F octahedra that share  a cornercorner with one Mg(1)O5F octahedra, corners with two equivalent Fe(3)O5F octahedra,  a cornercorner with one Fe(4)O5 square pyramid, corners with two equivalent Fe(5)O5 square pyramids,  an edgeedge with one Fe(1)O5F octahedra,  an edgeedge with one Fe(7)O6 octahedra, and  a faceface with one Mg(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 51-61°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(1), 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(6), and one Fe(8) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(5) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(7) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(5) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(4), one Fe(5), and one Fe(8) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Fe(2), one Fe(4), and one Fe(6) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(3), one Fe(5), and one Fe(8) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Fe(4), one Fe(5), and one Fe(7) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(4) atom. In the eleventh O site, O(11) is bonded in a distorted see-saw-like geometry to one Mg(1), one Fe(3), one Fe(7), and one Fe(8) atom. In the twelfth O site, O(12) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(2), and one Fe(7) atom. In the thirteenth O site, O(13) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(6), one Fe(7), and one Fe(8) atom. In the fourteenth O site, O(14) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(4), one Fe(6), and one Fe(7) atom. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(1), and one Fe(8) atom. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(6) atom.
MgFe8(O7F)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(11), one O(12), one O(13), one O(14), one O(8), and one F(1) atom to form MgO5F octahedra that share  a cornercorner with one Fe(1)O5F octahedra,  a cornercorner with one Fe(2)O5F octahedra,  a cornercorner with one Fe(8)O5F octahedra,  a cornercorner with one Fe(7)O6 octahedra,  a cornercorner with one Fe(4)O5 square pyramid,  a cornercorner with one Fe(5)O5 square pyramid,  an edgeedge with one Fe(3)O5F octahedra,  a faceface with one Fe(8)O5F octahedra, and  a faceface with one Fe(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-52°. The Mg(1)-O(11) bond length is 2.07 Å. The Mg(1)-O(12) bond length is 2.09 Å. The Mg(1)-O(13) bond length is 2.04 Å. The Mg(1)-O(14) bond length is 2.00 Å. The Mg(1)-O(8) bond length is 2.01 Å. The Mg(1)-F(1) bond length is 2.10 Å. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(10), one O(2), one O(3), one O(5), and one F(1) atom to form FeO5F octahedra that share  a cornercorner with one Mg(1)O5F octahedra, corners with two equivalent Fe(3)O5F octahedra,  a cornercorner with one Fe(4)O5 square pyramid, corners with two equivalent Fe(5)O5 square pyramids,  an edgeedge with one Fe(2)O5F octahedra, and  an edgeedge with one Fe(8)O5F octahedra. The corner-sharing octahedral tilt angles range from 43-51°. The Fe(1)-O(1) bond length is 2.05 Å. The Fe(1)-O(10) bond length is 1.99 Å. The Fe(1)-O(2) bond length is 1.97 Å. The Fe(1)-O(3) bond length is 2.00 Å. The Fe(1)-O(5) bond length is 2.11 Å. The Fe(1)-F(1) bond length is 2.13 Å. In the second Fe site, Fe(2) is bonded to one O(10), one O(12), one O(3), one O(4), one O(7), and one F(2) atom to form FeO5F octahedra that share  a cornercorner with one Mg(1)O5F octahedra, corners with two equivalent Fe(3)O5F octahedra,  a cornercorner with one Fe(5)O5 square pyramid, corners with two equivalent Fe(4)O5 square pyramids,  an edgeedge with one Fe(1)O5F octahedra, and  an edgeedge with one Fe(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-51°. The Fe(2)-O(10) bond length is 1.92 Å. The Fe(2)-O(12) bond length is 1.91 Å. The Fe(2)-O(3) bond length is 1.91 Å. The Fe(2)-O(4) bond length is 1.99 Å. The Fe(2)-O(7) bond length is 1.99 Å. The Fe(2)-F(2) bond length is 2.18 Å. In the third Fe site, Fe(3) is bonded to one O(1), one O(11), one O(4), one O(5), one O(8), and one F(2) atom to form distorted FeO5F octahedra that share corners with two equivalent Fe(1)O5F octahedra, corners with two equivalent Fe(2)O5F octahedra, corners with two equivalent Fe(8)O5F octahedra, corners with two equivalent Fe(7)O6 octahedra,  an edgeedge with one Mg(1)O5F octahedra, and  an edgeedge with one Fe(5)O5 square pyramid. The corner-sharing octahedral tilt angles range from 35-61°. The Fe(3)-O(1) bond length is 1.95 Å. The Fe(3)-O(11) bond length is 2.42 Å. The Fe(3)-O(4) bond length is 1.98 Å. The Fe(3)-O(5) bond length is 1.99 Å. The Fe(3)-O(8) bond length is 1.98 Å. The Fe(3)-F(2) bond length is 2.05 Å. In the fourth Fe site, Fe(4) is bonded to one O(10), one O(14), one O(6), one O(7), and one O(9) atom to form distorted FeO5 square pyramids that share  a cornercorner with one Mg(1)O5F octahedra,  a cornercorner with one Fe(1)O5F octahedra,  a cornercorner with one Fe(8)O5F octahedra, corners with two equivalent Fe(2)O5F octahedra, corners with two equivalent Fe(7)O6 octahedra, and  an edgeedge with one Fe(5)O5 square pyramid. The corner-sharing octahedral tilt angles range from 42-69°. The Fe(4)-O(10) bond length is 1.95 Å. The Fe(4)-O(14) bond length is 1.89 Å. The Fe(4)-O(6) bond length is 1.93 Å. The Fe(4)-O(7) bond length is 1.88 Å. The Fe(4)-O(9) bond length is 1.91 Å. In the fifth Fe site, Fe(5) is bonded to one O(3), one O(5), one O(6), one O(8), and one O(9) atom to form FeO5 square pyramids that share  a cornercorner with one Mg(1)O5F octahedra,  a cornercorner with one Fe(2)O5F octahedra,  a cornercorner with one Fe(7)O6 octahedra, corners with two equivalent Fe(1)O5F octahedra, corners with two equivalent Fe(8)O5F octahedra,  an edgeedge with one Fe(3)O5F octahedra, and  an edgeedge with one Fe(4)O5 square pyramid. The corner-sharing octahedral tilt angles range from 46-73°. The Fe(5)-O(3) bond length is 1.95 Å. The Fe(5)-O(5) bond length is 1.89 Å. The Fe(5)-O(6) bond length is 1.92 Å. The Fe(5)-O(8) bond length is 1.92 Å. The Fe(5)-O(9) bond length is 1.94 Å. In the sixth Fe site, Fe(6) is bonded in a 6-coordinate geometry to one O(1), one O(13), one O(14), one O(2), one O(7), and one F(2) atom. The Fe(6)-O(1) bond length is 1.94 Å. The Fe(6)-O(13) bond length is 2.61 Å. The Fe(6)-O(14) bond length is 2.03 Å. The Fe(6)-O(2) bond length is 1.94 Å. The Fe(6)-O(7) bond length is 1.95 Å. The Fe(6)-F(2) bond length is 2.10 Å. In the seventh Fe site, Fe(7) is bonded to one O(11), one O(12), one O(13), one O(14), one O(4), and one O(9) atom to form distorted FeO6 octahedra that share  a cornercorner with one Mg(1)O5F octahedra, corners with two equivalent Fe(3)O5F octahedra,  a cornercorner with one Fe(5)O5 square pyramid, corners with two equivalent Fe(4)O5 square pyramids,  an edgeedge with one Fe(2)O5F octahedra,  an edgeedge with one Fe(8)O5F octahedra, and  a faceface with one Mg(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 35-52°. The Fe(7)-O(11) bond length is 1.97 Å. The Fe(7)-O(12) bond length is 1.90 Å. The Fe(7)-O(13) bond length is 1.86 Å. The Fe(7)-O(14) bond length is 2.44 Å. The Fe(7)-O(4) bond length is 1.91 Å. The Fe(7)-O(9) bond length is 1.99 Å. In the eighth Fe site, Fe(8) is bonded to one O(11), one O(13), one O(2), one O(6), one O(8), and one F(1) atom to form distorted FeO5F octahedra that share  a cornercorner with one Mg(1)O5F octahedra, corners with two equivalent Fe(3)O5F octahedra,  a cornercorner with one Fe(4)O5 square pyramid, corners with two equivalent Fe(5)O5 square pyramids,  an edgeedge with one Fe(1)O5F octahedra,  an edgeedge with one Fe(7)O6 octahedra, and  a faceface with one Mg(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 51-61°. The Fe(8)-O(11) bond length is 1.92 Å. The Fe(8)-O(13) bond length is 2.05 Å. The Fe(8)-O(2) bond length is 1.91 Å. The Fe(8)-O(6) bond length is 1.95 Å. The Fe(8)-O(8) bond length is 2.34 Å. The Fe(8)-F(1) bond length is 2.13 Å. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(1), 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(6), and one Fe(8) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(5) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(7) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(3), and one Fe(5) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(4), one Fe(5), and one Fe(8) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Fe(2), one Fe(4), and one Fe(6) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(3), one Fe(5), and one Fe(8) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Fe(4), one Fe(5), and one Fe(7) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(4) atom. In the eleventh O site, O(11) is bonded in a distorted see-saw-like geometry to one Mg(1), one Fe(3), one Fe(7), and one Fe(8) atom. In the twelfth O site, O(12) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(2), and one Fe(7) atom. In the thirteenth O site, O(13) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(6), one Fe(7), and one Fe(8) atom. In the fourteenth O site, O(14) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(4), one Fe(6), and one Fe(7) atom. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(1), and one Fe(8) atom. In the second F site, F(2) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(6) atom.