MgFe12(OF)12 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(4), two equivalent O(1), two equivalent O(6), and one F(3) atom to form distorted MgO5F octahedra that share edges with two equivalent Mg(1)O5F octahedra, edges with two equivalent Fe(4)O3F3 octahedra, and edges with two equivalent Fe(5)O3F3 octahedra. There are twelve inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), two equivalent O(12), two equivalent O(2), and one F(9) atom to form FeO5F octahedra that share corners with two equivalent Fe(12)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with two equivalent Fe(6)O3F3 octahedra, and edges with two equivalent Fe(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 48-56°. In the second Fe site, Fe(2) is bonded in a 6-coordinate geometry to one O(4), two equivalent O(1), one F(8), and two equivalent F(11) atoms. In the third Fe site, Fe(3) is bonded to one F(10), one F(2), two equivalent F(1), and two equivalent F(12) atoms to form FeF6 octahedra that share corners with two equivalent Fe(11)O3F3 octahedra, corners with two equivalent Fe(12)O3F3 octahedra, corners with two equivalent Fe(5)O3F3 octahedra, corners with two equivalent Fe(6)O3F3 octahedra, and edges with two equivalent Fe(3)F6 octahedra. The corner-sharing octahedral tilt angles range from 47-48°. In the fourth Fe site, Fe(4) is bonded to one O(1), two equivalent O(3), one F(5), and two equivalent F(3) atoms to form distorted FeO3F3 octahedra that share corners with two equivalent Fe(8)O4F2 octahedra, corners with two equivalent Fe(1)O5F octahedra, edges with two equivalent Mg(1)O5F octahedra, and edges with two equivalent Fe(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-56°. In the fifth Fe site, Fe(5) is bonded to one O(6), two equivalent O(4), one F(1), and two equivalent F(4) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(3)F6 octahedra, corners with two equivalent Fe(9)O3F3 octahedra, edges with two equivalent Mg(1)O5F octahedra, and edges with two equivalent Fe(5)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 47-48°. In the sixth Fe site, Fe(6) is bonded to one O(2), two equivalent O(5), one F(6), and two equivalent F(2) atoms to form distorted FeO3F3 octahedra that share corners with two equivalent Fe(3)F6 octahedra, corners with two equivalent Fe(9)O3F3 octahedra, corners with two equivalent Fe(8)O4F2 octahedra, corners with two equivalent Fe(1)O5F octahedra, and edges with two equivalent Fe(6)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 47-53°. In the seventh Fe site, Fe(7) is bonded in a 6-coordinate geometry to one O(10), two equivalent O(6), one F(3), and two equivalent F(7) atoms. In the eighth Fe site, Fe(8) is bonded to one O(5), one O(9), two equivalent O(7), and two equivalent F(5) atoms to form FeO4F2 octahedra that share corners with two equivalent Fe(12)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with two equivalent Fe(6)O3F3 octahedra, and edges with two equivalent Fe(8)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 46-53°. In the ninth Fe site, Fe(9) is bonded to one O(11), two equivalent O(8), one F(4), and two equivalent F(6) atoms to form a mixture of corner and edge-sharing FeO3F3 octahedra. The corner-sharing octahedral tilt angles range from 48-52°. In the tenth Fe site, Fe(10) is bonded in a 6-coordinate geometry to one O(12), two equivalent O(9), one F(7), and two equivalent F(8) atoms. In the eleventh Fe site, Fe(11) is bonded to one O(8), two equivalent O(10), one F(11), and two equivalent F(10) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(3)F6 octahedra, corners with two equivalent Fe(9)O3F3 octahedra, and edges with two equivalent Fe(11)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 47-52°. In the twelfth Fe site, Fe(12) is bonded to one O(7), two equivalent O(11), one F(12), and two equivalent F(9) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(3)F6 octahedra, corners with two equivalent Fe(9)O3F3 octahedra, corners with two equivalent Fe(8)O4F2 octahedra, corners with two equivalent Fe(1)O5F octahedra, and edges with two equivalent Fe(12)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Mg(1), one Fe(4), and two equivalent Fe(2) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(6) and two equivalent Fe(1) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(1) and two equivalent Fe(4) atoms. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(2), and two equivalent Fe(5) atoms. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Fe(8) and two equivalent Fe(6) atoms. In the sixth O site, O(6) is bonded to two equivalent Mg(1), one Fe(5), and two equivalent Fe(7) atoms to form distorted edge-sharing OMg2Fe3 trigonal bipyramids. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Fe(12) and two equivalent Fe(8) atoms. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Fe(11) and two equivalent Fe(9) atoms. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Fe(8) and two equivalent Fe(10) atoms. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Fe(7) and two equivalent Fe(11) atoms. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one Fe(9) and two equivalent Fe(12) atoms. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Fe(10) and two equivalent Fe(1) atoms. There are twelve inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Fe(5) and two equivalent Fe(3) atoms. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Fe(3) and two equivalent Fe(6) atoms. In the third F site, F(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(7), and two equivalent Fe(4) atoms. In the fourth F site, F(4) is bonded in a distorted trigonal planar geometry to one Fe(9) and two equivalent Fe(5) atoms. In the fifth F site, F(5) is bonded in a distorted T-shaped geometry to one Fe(4) and two equivalent Fe(8) atoms. In the sixth F site, F(6) is bonded in a distorted trigonal planar geometry to one Fe(6) and two equivalent Fe(9) atoms. In the seventh F site, F(7) is bonded in a 3-coordinate geometry to one Fe(10) and two equivalent Fe(7) atoms. In the eighth F site, F(8) is bonded in a distorted T-shaped geometry to one Fe(2) and two equivalent Fe(10) atoms. In the ninth F site, F(9) is bonded in a distorted trigonal planar geometry to one Fe(1) and two equivalent Fe(12) atoms. In the tenth F site, F(10) is bonded in a distorted T-shaped geometry to one Fe(3) and two equivalent Fe(11) atoms. In the eleventh F site, F(11) is bonded in a distorted T-shaped geometry to one Fe(11) and two equivalent Fe(2) atoms. In the twelfth F site, F(12) is bonded in a distorted trigonal planar geometry to one Fe(12) and two equivalent Fe(3) atoms.
MgFe12(OF)12 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(4), two equivalent O(1), two equivalent O(6), and one F(3) atom to form distorted MgO5F octahedra that share edges with two equivalent Mg(1)O5F octahedra, edges with two equivalent Fe(4)O3F3 octahedra, and edges with two equivalent Fe(5)O3F3 octahedra. The Mg(1)-O(4) bond length is 1.96 Å. There is one shorter (2.05 Å) and one longer (2.06 Å) Mg(1)-O(1) bond length. There is one shorter (2.24 Å) and one longer (2.27 Å) Mg(1)-O(6) bond length. The Mg(1)-F(3) bond length is 1.91 Å. There are twelve inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), two equivalent O(12), two equivalent O(2), and one F(9) atom to form FeO5F octahedra that share corners with two equivalent Fe(12)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with two equivalent Fe(6)O3F3 octahedra, and edges with two equivalent Fe(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 48-56°. The Fe(1)-O(3) bond length is 2.04 Å. Both Fe(1)-O(12) bond lengths are 2.02 Å. Both Fe(1)-O(2) bond lengths are 2.01 Å. The Fe(1)-F(9) bond length is 2.18 Å. In the second Fe site, Fe(2) is bonded in a 6-coordinate geometry to one O(4), two equivalent O(1), one F(8), and two equivalent F(11) atoms. The Fe(2)-O(4) bond length is 2.44 Å. There is one shorter (2.23 Å) and one longer (2.27 Å) Fe(2)-O(1) bond length. The Fe(2)-F(8) bond length is 2.02 Å. There is one shorter (2.11 Å) and one longer (2.12 Å) Fe(2)-F(11) bond length. In the third Fe site, Fe(3) is bonded to one F(10), one F(2), two equivalent F(1), and two equivalent F(12) atoms to form FeF6 octahedra that share corners with two equivalent Fe(11)O3F3 octahedra, corners with two equivalent Fe(12)O3F3 octahedra, corners with two equivalent Fe(5)O3F3 octahedra, corners with two equivalent Fe(6)O3F3 octahedra, and edges with two equivalent Fe(3)F6 octahedra. The corner-sharing octahedral tilt angles range from 47-48°. The Fe(3)-F(10) bond length is 2.21 Å. The Fe(3)-F(2) bond length is 2.04 Å. Both Fe(3)-F(1) bond lengths are 2.12 Å. Both Fe(3)-F(12) bond lengths are 2.06 Å. In the fourth Fe site, Fe(4) is bonded to one O(1), two equivalent O(3), one F(5), and two equivalent F(3) atoms to form distorted FeO3F3 octahedra that share corners with two equivalent Fe(8)O4F2 octahedra, corners with two equivalent Fe(1)O5F octahedra, edges with two equivalent Mg(1)O5F octahedra, and edges with two equivalent Fe(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-56°. The Fe(4)-O(1) bond length is 2.04 Å. There is one shorter (1.87 Å) and one longer (1.88 Å) Fe(4)-O(3) bond length. The Fe(4)-F(5) bond length is 2.06 Å. There is one shorter (2.30 Å) and one longer (2.32 Å) Fe(4)-F(3) bond length. In the fifth Fe site, Fe(5) is bonded to one O(6), two equivalent O(4), one F(1), and two equivalent F(4) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(3)F6 octahedra, corners with two equivalent Fe(9)O3F3 octahedra, edges with two equivalent Mg(1)O5F octahedra, and edges with two equivalent Fe(5)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 47-48°. The Fe(5)-O(6) bond length is 2.20 Å. Both Fe(5)-O(4) bond lengths are 1.95 Å. The Fe(5)-F(1) bond length is 2.00 Å. Both Fe(5)-F(4) bond lengths are 2.09 Å. In the sixth Fe site, Fe(6) is bonded to one O(2), two equivalent O(5), one F(6), and two equivalent F(2) atoms to form distorted FeO3F3 octahedra that share corners with two equivalent Fe(3)F6 octahedra, corners with two equivalent Fe(9)O3F3 octahedra, corners with two equivalent Fe(8)O4F2 octahedra, corners with two equivalent Fe(1)O5F octahedra, and edges with two equivalent Fe(6)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 47-53°. The Fe(6)-O(2) bond length is 1.89 Å. Both Fe(6)-O(5) bond lengths are 1.93 Å. The Fe(6)-F(6) bond length is 2.37 Å. Both Fe(6)-F(2) bond lengths are 2.19 Å. In the seventh Fe site, Fe(7) is bonded in a 6-coordinate geometry to one O(10), two equivalent O(6), one F(3), and two equivalent F(7) atoms. The Fe(7)-O(10) bond length is 1.86 Å. Both Fe(7)-O(6) bond lengths are 2.09 Å. The Fe(7)-F(3) bond length is 2.48 Å. Both Fe(7)-F(7) bond lengths are 2.02 Å. In the eighth Fe site, Fe(8) is bonded to one O(5), one O(9), two equivalent O(7), and two equivalent F(5) atoms to form FeO4F2 octahedra that share corners with two equivalent Fe(12)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with two equivalent Fe(6)O3F3 octahedra, and edges with two equivalent Fe(8)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 46-53°. The Fe(8)-O(5) bond length is 2.01 Å. The Fe(8)-O(9) bond length is 2.03 Å. Both Fe(8)-O(7) bond lengths are 1.95 Å. There is one shorter (2.16 Å) and one longer (2.17 Å) Fe(8)-F(5) bond length. In the ninth Fe site, Fe(9) is bonded to one O(11), two equivalent O(8), one F(4), and two equivalent F(6) atoms to form a mixture of corner and edge-sharing FeO3F3 octahedra. The corner-sharing octahedral tilt angles range from 48-52°. The Fe(9)-O(11) bond length is 1.90 Å. Both Fe(9)-O(8) bond lengths are 1.97 Å. The Fe(9)-F(4) bond length is 2.27 Å. There is one shorter (2.08 Å) and one longer (2.09 Å) Fe(9)-F(6) bond length. In the tenth Fe site, Fe(10) is bonded in a 6-coordinate geometry to one O(12), two equivalent O(9), one F(7), and two equivalent F(8) atoms. The Fe(10)-O(12) bond length is 1.87 Å. Both Fe(10)-O(9) bond lengths are 1.92 Å. The Fe(10)-F(7) bond length is 2.51 Å. There is one shorter (2.23 Å) and one longer (2.26 Å) Fe(10)-F(8) bond length. In the eleventh Fe site, Fe(11) is bonded to one O(8), two equivalent O(10), one F(11), and two equivalent F(10) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(3)F6 octahedra, corners with two equivalent Fe(9)O3F3 octahedra, and edges with two equivalent Fe(11)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 47-52°. The Fe(11)-O(8) bond length is 1.91 Å. There is one shorter (1.97 Å) and one longer (1.98 Å) Fe(11)-O(10) bond length. The Fe(11)-F(11) bond length is 2.10 Å. Both Fe(11)-F(10) bond lengths are 2.11 Å. In the twelfth Fe site, Fe(12) is bonded to one O(7), two equivalent O(11), one F(12), and two equivalent F(9) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(3)F6 octahedra, corners with two equivalent Fe(9)O3F3 octahedra, corners with two equivalent Fe(8)O4F2 octahedra, corners with two equivalent Fe(1)O5F octahedra, and edges with two equivalent Fe(12)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. The Fe(12)-O(7) bond length is 1.93 Å. Both Fe(12)-O(11) bond lengths are 1.96 Å. The Fe(12)-F(12) bond length is 2.14 Å. There is one shorter (2.08 Å) and one longer (2.09 Å) Fe(12)-F(9) bond length. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Mg(1), one Fe(4), and two equivalent Fe(2) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(6) and two equivalent Fe(1) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(1) and two equivalent Fe(4) atoms. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(2), and two equivalent Fe(5) atoms. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Fe(8) and two equivalent Fe(6) atoms. In the sixth O site, O(6) is bonded to two equivalent Mg(1), one Fe(5), and two equivalent Fe(7) atoms to form distorted edge-sharing OMg2Fe3 trigonal bipyramids. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Fe(12) and two equivalent Fe(8) atoms. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Fe(11) and two equivalent Fe(9) atoms. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Fe(8) and two equivalent Fe(10) atoms. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Fe(7) and two equivalent Fe(11) atoms. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one Fe(9) and two equivalent Fe(12) atoms. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Fe(10) and two equivalent Fe(1) atoms. There are twelve inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Fe(5) and two equivalent Fe(3) atoms. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Fe(3) and two equivalent Fe(6) atoms. In the third F site, F(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(7), and two equivalent Fe(4) atoms. In the fourth F site, F(4) is bonded in a distorted trigonal planar geometry to one Fe(9) and two equivalent Fe(5) atoms. In the fifth F site, F(5) is bonded in a distorted T-shaped geometry to one Fe(4) and two equivalent Fe(8) atoms. In the sixth F site, F(6) is bonded in a distorted trigonal planar geometry to one Fe(6) and two equivalent Fe(9) atoms. In the seventh F site, F(7) is bonded in a 3-coordinate geometry to one Fe(10) and two equivalent Fe(7) atoms. In the eighth F site, F(8) is bonded in a distorted T-shaped geometry to one Fe(2) and two equivalent Fe(10) atoms. In the ninth F site, F(9) is bonded in a distorted trigonal planar geometry to one Fe(1) and two equivalent Fe(12) atoms. In the tenth F site, F(10) is bonded in a distorted T-shaped geometry to one Fe(3) and two equivalent Fe(11) atoms. In the eleventh F site, F(11) is bonded in a distorted T-shaped geometry to one Fe(11) and two equivalent Fe(2) atoms. In the twelfth F site, F(12) is bonded in a distorted trigonal planar geometry to one Fe(12) and two equivalent Fe(3) atoms.