MgFe6Sb10(O3I)6 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a tetrahedral geometry to one Sb(4), one I(1), one I(4), and one I(6) atom. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 3-coordinate geometry to one O(12), one O(3), one O(5), one I(3), and one I(5) atom. In the second Fe site, Fe(2) is bonded in a 3-coordinate geometry to one O(11), one O(4), one O(6), and one I(4) atom. In the third Fe site, Fe(3) is bonded in a distorted see-saw-like geometry to one O(1), one O(10), one O(2), one O(5), and one I(2) atom. In the fourth Fe site, Fe(4) is bonded in a distorted see-saw-like geometry to one O(1), one O(2), one O(6), and one O(9) atom. In the fifth Fe site, Fe(5) is bonded in a 5-coordinate geometry to one O(18), one O(2), one O(5), one O(7), and one O(8) atom. In the sixth Fe site, Fe(6) is bonded in a 5-coordinate geometry to one O(1), one O(17), one O(6), one O(7), one O(8), and one I(2) atom. There are ten inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 3-coordinate geometry to one O(16), one O(3), one O(4), and one I(5) atom. In the second Sb site, Sb(2) is bonded in a 3-coordinate geometry to one O(15), one O(3), one O(4), and one I(6) atom. In the third Sb site, Sb(3) is bonded in a 5-coordinate geometry to one O(10), one O(12), one O(13), one O(16), one O(18), and one I(5) atom. In the fourth Sb site, Sb(4) is bonded in a 5-coordinate geometry to one Mg(1), one O(11), one O(14), one O(15), and one O(17) atom. In the fifth Sb site, Sb(5) is bonded in a distorted T-shaped geometry to one O(11), one O(7), and one O(9) atom. In the sixth Sb site, Sb(6) is bonded in a 3-coordinate geometry to one O(10), one O(12), one O(8), and one I(2) atom. In the seventh Sb site, Sb(7) is bonded in a 4-coordinate geometry to one O(1), one O(13), one O(18), and one O(7) atom. In the eighth Sb site, Sb(8) is bonded in a distorted rectangular see-saw-like geometry to one O(14), one O(17), one O(2), and one O(8) atom. In the ninth Sb site, Sb(9) is bonded in a 3-coordinate geometry to one O(13), one O(16), one O(5), and one I(5) atom. In the tenth Sb site, Sb(10) is bonded in a 3-coordinate geometry to one O(14), one O(15), one O(6), and one I(2) atom. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded to one Fe(3), one Fe(4), one Fe(6), and one Sb(7) atom to form OFe3Sb tetrahedra that share  a cornercorner with one O(5)Fe3Sb tetrahedra,  a cornercorner with one O(8)Fe2Sb2 trigonal pyramid,  an edgeedge with one O(7)Fe2Sb2 tetrahedra,  an edgeedge with one O(2)Fe3Sb tetrahedra, and  an edgeedge with one O(6)Fe3Sb tetrahedra. In the second O site, O(2) is bonded to one Fe(3), one Fe(4), one Fe(5), and one Sb(8) atom to form OFe3Sb tetrahedra that share  a cornercorner with one O(7)Fe2Sb2 tetrahedra,  a cornercorner with one O(6)Fe3Sb tetrahedra,  an edgeedge with one O(1)Fe3Sb tetrahedra,  an edgeedge with one O(5)Fe3Sb tetrahedra, and  an edgeedge with one O(8)Fe2Sb2 trigonal pyramid. In the third O site, O(3) is bonded in a trigonal non-coplanar geometry to one Fe(1), one Sb(1), and one Sb(2) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Fe(2), one Sb(1), and one Sb(2) atom. In the fifth O site, O(5) is bonded to one Fe(1), one Fe(3), one Fe(5), and one Sb(9) atom to form OFe3Sb tetrahedra that share  a cornercorner with one O(7)Fe2Sb2 tetrahedra,  a cornercorner with one O(1)Fe3Sb tetrahedra,  a cornercorner with one O(8)Fe2Sb2 trigonal pyramid, and  an edgeedge with one O(2)Fe3Sb tetrahedra. In the sixth O site, O(6) is bonded to one Fe(2), one Fe(4), one Fe(6), and one Sb(10) atom to form OFe3Sb tetrahedra that share  a cornercorner with one O(7)Fe2Sb2 tetrahedra,  a cornercorner with one O(2)Fe3Sb tetrahedra,  a cornercorner with one O(8)Fe2Sb2 trigonal pyramid, and  an edgeedge with one O(1)Fe3Sb tetrahedra. In the seventh O site, O(7) is bonded to one Fe(5), one Fe(6), one Sb(5), and one Sb(7) atom to form distorted OFe2Sb2 tetrahedra that share  a cornercorner with one O(2)Fe3Sb tetrahedra,  a cornercorner with one O(5)Fe3Sb tetrahedra,  a cornercorner with one O(6)Fe3Sb tetrahedra,  an edgeedge with one O(1)Fe3Sb tetrahedra, and  an edgeedge with one O(8)Fe2Sb2 trigonal pyramid. In the eighth O site, O(8) is bonded to one Fe(5), one Fe(6), one Sb(6), and one Sb(8) atom to form distorted OFe2Sb2 trigonal pyramids that share  a cornercorner with one O(1)Fe3Sb tetrahedra,  a cornercorner with one O(5)Fe3Sb tetrahedra,  a cornercorner with one O(6)Fe3Sb tetrahedra,  an edgeedge with one O(7)Fe2Sb2 tetrahedra, and  an edgeedge with one O(2)Fe3Sb tetrahedra. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Fe(4) and one Sb(5) atom. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Fe(3), one Sb(3), and one Sb(6) atom. In the eleventh O site, O(11) is bonded in a 2-coordinate geometry to one Fe(2), one Sb(4), and one Sb(5) atom. In the twelfth O site, O(12) is bonded in a trigonal planar geometry to one Fe(1), one Sb(3), and one Sb(6) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Sb(3), one Sb(7), and one Sb(9) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal non-coplanar geometry to one Sb(10), one Sb(4), and one Sb(8) atom. In the fifteenth O site, O(15) is bonded in a distorted trigonal planar geometry to one Sb(10), one Sb(2), and one Sb(4) atom. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Sb(1), one Sb(3), and one Sb(9) atom. In the seventeenth O site, O(17) is bonded in a trigonal planar geometry to one Fe(6), one Sb(4), and one Sb(8) atom. In the eighteenth O site, O(18) is bonded in a trigonal non-coplanar geometry to one Fe(5), one Sb(3), and one Sb(7) atom. There are six inequivalent I sites. In the first I site, I(1) is bonded in a 1-coordinate geometry to one Mg(1) atom. In the second I site, I(2) is bonded in a 4-coordinate geometry to one Fe(3), one Fe(6), one Sb(10), and one Sb(6) atom. In the third I site, I(3) is bonded in a distorted single-bond geometry to one Fe(1) atom. In the fourth I site, I(4) is bonded in a bent 150 degrees geometry to one Mg(1) and one Fe(2) atom. In the fifth I site, I(5) is bonded in a 4-coordinate geometry to one Fe(1), one Sb(1), one Sb(3), and one Sb(9) atom. In the sixth I site, I(6) is bonded in a 2-coordinate geometry to one Mg(1) and one Sb(2) atom.
MgFe6Sb10(O3I)6 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a tetrahedral geometry to one Sb(4), one I(1), one I(4), and one I(6) atom. The Mg(1)-Sb(4) bond length is 2.86 Å. The Mg(1)-I(1) bond length is 2.81 Å. The Mg(1)-I(4) bond length is 2.82 Å. The Mg(1)-I(6) bond length is 2.94 Å. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 3-coordinate geometry to one O(12), one O(3), one O(5), one I(3), and one I(5) atom. The Fe(1)-O(12) bond length is 1.97 Å. The Fe(1)-O(3) bond length is 2.02 Å. The Fe(1)-O(5) bond length is 2.14 Å. The Fe(1)-I(3) bond length is 2.84 Å. The Fe(1)-I(5) bond length is 3.10 Å. In the second Fe site, Fe(2) is bonded in a 3-coordinate geometry to one O(11), one O(4), one O(6), and one I(4) atom. The Fe(2)-O(11) bond length is 1.90 Å. The Fe(2)-O(4) bond length is 2.00 Å. The Fe(2)-O(6) bond length is 2.12 Å. The Fe(2)-I(4) bond length is 2.99 Å. In the third Fe site, Fe(3) is bonded in a distorted see-saw-like geometry to one O(1), one O(10), one O(2), one O(5), and one I(2) atom. The Fe(3)-O(1) bond length is 2.23 Å. The Fe(3)-O(10) bond length is 2.06 Å. The Fe(3)-O(2) bond length is 2.11 Å. The Fe(3)-O(5) bond length is 2.19 Å. The Fe(3)-I(2) bond length is 3.10 Å. In the fourth Fe site, Fe(4) is bonded in a distorted see-saw-like geometry to one O(1), one O(2), one O(6), and one O(9) atom. The Fe(4)-O(1) bond length is 2.12 Å. The Fe(4)-O(2) bond length is 2.18 Å. The Fe(4)-O(6) bond length is 2.14 Å. The Fe(4)-O(9) bond length is 1.93 Å. In the fifth Fe site, Fe(5) is bonded in a 5-coordinate geometry to one O(18), one O(2), one O(5), one O(7), and one O(8) atom. The Fe(5)-O(18) bond length is 2.06 Å. The Fe(5)-O(2) bond length is 2.10 Å. The Fe(5)-O(5) bond length is 2.31 Å. The Fe(5)-O(7) bond length is 2.26 Å. The Fe(5)-O(8) bond length is 2.22 Å. In the sixth Fe site, Fe(6) is bonded in a 5-coordinate geometry to one O(1), one O(17), one O(6), one O(7), one O(8), and one I(2) atom. The Fe(6)-O(1) bond length is 2.15 Å. The Fe(6)-O(17) bond length is 2.03 Å. The Fe(6)-O(6) bond length is 2.37 Å. The Fe(6)-O(7) bond length is 2.21 Å. The Fe(6)-O(8) bond length is 2.41 Å. The Fe(6)-I(2) bond length is 3.11 Å. There are ten inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 3-coordinate geometry to one O(16), one O(3), one O(4), and one I(5) atom. The Sb(1)-O(16) bond length is 2.00 Å. The Sb(1)-O(3) bond length is 2.06 Å. The Sb(1)-O(4) bond length is 2.14 Å. The Sb(1)-I(5) bond length is 3.16 Å. In the second Sb site, Sb(2) is bonded in a 3-coordinate geometry to one O(15), one O(3), one O(4), and one I(6) atom. The Sb(2)-O(15) bond length is 1.99 Å. The Sb(2)-O(3) bond length is 2.10 Å. The Sb(2)-O(4) bond length is 2.06 Å. The Sb(2)-I(6) bond length is 3.21 Å. In the third Sb site, Sb(3) is bonded in a 5-coordinate geometry to one O(10), one O(12), one O(13), one O(16), one O(18), and one I(5) atom. The Sb(3)-O(10) bond length is 2.11 Å. The Sb(3)-O(12) bond length is 2.20 Å. The Sb(3)-O(13) bond length is 2.20 Å. The Sb(3)-O(16) bond length is 2.66 Å. The Sb(3)-O(18) bond length is 2.06 Å. The Sb(3)-I(5) bond length is 3.53 Å. In the fourth Sb site, Sb(4) is bonded in a 5-coordinate geometry to one Mg(1), one O(11), one O(14), one O(15), and one O(17) atom. The Sb(4)-O(11) bond length is 2.77 Å. The Sb(4)-O(14) bond length is 2.16 Å. The Sb(4)-O(15) bond length is 2.52 Å. The Sb(4)-O(17) bond length is 2.14 Å. In the fifth Sb site, Sb(5) is bonded in a distorted T-shaped geometry to one O(11), one O(7), and one O(9) atom. The Sb(5)-O(11) bond length is 1.97 Å. The Sb(5)-O(7) bond length is 2.08 Å. The Sb(5)-O(9) bond length is 1.95 Å. In the sixth Sb site, Sb(6) is bonded in a 3-coordinate geometry to one O(10), one O(12), one O(8), and one I(2) atom. The Sb(6)-O(10) bond length is 2.08 Å. The Sb(6)-O(12) bond length is 2.01 Å. The Sb(6)-O(8) bond length is 2.02 Å. The Sb(6)-I(2) bond length is 3.39 Å. In the seventh Sb site, Sb(7) is bonded in a 4-coordinate geometry to one O(1), one O(13), one O(18), and one O(7) atom. The Sb(7)-O(1) bond length is 2.03 Å. The Sb(7)-O(13) bond length is 2.24 Å. The Sb(7)-O(18) bond length is 2.04 Å. The Sb(7)-O(7) bond length is 2.19 Å. In the eighth Sb site, Sb(8) is bonded in a distorted rectangular see-saw-like geometry to one O(14), one O(17), one O(2), and one O(8) atom. The Sb(8)-O(14) bond length is 2.25 Å. The Sb(8)-O(17) bond length is 2.01 Å. The Sb(8)-O(2) bond length is 2.05 Å. The Sb(8)-O(8) bond length is 2.21 Å. In the ninth Sb site, Sb(9) is bonded in a 3-coordinate geometry to one O(13), one O(16), one O(5), and one I(5) atom. The Sb(9)-O(13) bond length is 2.03 Å. The Sb(9)-O(16) bond length is 2.03 Å. The Sb(9)-O(5) bond length is 2.01 Å. The Sb(9)-I(5) bond length is 3.46 Å. In the tenth Sb site, Sb(10) is bonded in a 3-coordinate geometry to one O(14), one O(15), one O(6), and one I(2) atom. The Sb(10)-O(14) bond length is 2.01 Å. The Sb(10)-O(15) bond length is 2.07 Å. The Sb(10)-O(6) bond length is 2.01 Å. The Sb(10)-I(2) bond length is 3.34 Å. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded to one Fe(3), one Fe(4), one Fe(6), and one Sb(7) atom to form OFe3Sb tetrahedra that share  a cornercorner with one O(5)Fe3Sb tetrahedra,  a cornercorner with one O(8)Fe2Sb2 trigonal pyramid,  an edgeedge with one O(7)Fe2Sb2 tetrahedra,  an edgeedge with one O(2)Fe3Sb tetrahedra, and  an edgeedge with one O(6)Fe3Sb tetrahedra. In the second O site, O(2) is bonded to one Fe(3), one Fe(4), one Fe(5), and one Sb(8) atom to form OFe3Sb tetrahedra that share  a cornercorner with one O(7)Fe2Sb2 tetrahedra,  a cornercorner with one O(6)Fe3Sb tetrahedra,  an edgeedge with one O(1)Fe3Sb tetrahedra,  an edgeedge with one O(5)Fe3Sb tetrahedra, and  an edgeedge with one O(8)Fe2Sb2 trigonal pyramid. In the third O site, O(3) is bonded in a trigonal non-coplanar geometry to one Fe(1), one Sb(1), and one Sb(2) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Fe(2), one Sb(1), and one Sb(2) atom. In the fifth O site, O(5) is bonded to one Fe(1), one Fe(3), one Fe(5), and one Sb(9) atom to form OFe3Sb tetrahedra that share  a cornercorner with one O(7)Fe2Sb2 tetrahedra,  a cornercorner with one O(1)Fe3Sb tetrahedra,  a cornercorner with one O(8)Fe2Sb2 trigonal pyramid, and  an edgeedge with one O(2)Fe3Sb tetrahedra. In the sixth O site, O(6) is bonded to one Fe(2), one Fe(4), one Fe(6), and one Sb(10) atom to form OFe3Sb tetrahedra that share  a cornercorner with one O(7)Fe2Sb2 tetrahedra,  a cornercorner with one O(2)Fe3Sb tetrahedra,  a cornercorner with one O(8)Fe2Sb2 trigonal pyramid, and  an edgeedge with one O(1)Fe3Sb tetrahedra. In the seventh O site, O(7) is bonded to one Fe(5), one Fe(6), one Sb(5), and one Sb(7) atom to form distorted OFe2Sb2 tetrahedra that share  a cornercorner with one O(2)Fe3Sb tetrahedra,  a cornercorner with one O(5)Fe3Sb tetrahedra,  a cornercorner with one O(6)Fe3Sb tetrahedra,  an edgeedge with one O(1)Fe3Sb tetrahedra, and  an edgeedge with one O(8)Fe2Sb2 trigonal pyramid. In the eighth O site, O(8) is bonded to one Fe(5), one Fe(6), one Sb(6), and one Sb(8) atom to form distorted OFe2Sb2 trigonal pyramids that share  a cornercorner with one O(1)Fe3Sb tetrahedra,  a cornercorner with one O(5)Fe3Sb tetrahedra,  a cornercorner with one O(6)Fe3Sb tetrahedra,  an edgeedge with one O(7)Fe2Sb2 tetrahedra, and  an edgeedge with one O(2)Fe3Sb tetrahedra. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Fe(4) and one Sb(5) atom. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Fe(3), one Sb(3), and one Sb(6) atom. In the eleventh O site, O(11) is bonded in a 2-coordinate geometry to one Fe(2), one Sb(4), and one Sb(5) atom. In the twelfth O site, O(12) is bonded in a trigonal planar geometry to one Fe(1), one Sb(3), and one Sb(6) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Sb(3), one Sb(7), and one Sb(9) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal non-coplanar geometry to one Sb(10), one Sb(4), and one Sb(8) atom. In the fifteenth O site, O(15) is bonded in a distorted trigonal planar geometry to one Sb(10), one Sb(2), and one Sb(4) atom. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Sb(1), one Sb(3), and one Sb(9) atom. In the seventeenth O site, O(17) is bonded in a trigonal planar geometry to one Fe(6), one Sb(4), and one Sb(8) atom. In the eighteenth O site, O(18) is bonded in a trigonal non-coplanar geometry to one Fe(5), one Sb(3), and one Sb(7) atom. There are six inequivalent I sites. In the first I site, I(1) is bonded in a 1-coordinate geometry to one Mg(1) atom. In the second I site, I(2) is bonded in a 4-coordinate geometry to one Fe(3), one Fe(6), one Sb(10), and one Sb(6) atom. In the third I site, I(3) is bonded in a distorted single-bond geometry to one Fe(1) atom. In the fourth I site, I(4) is bonded in a bent 150 degrees geometry to one Mg(1) and one Fe(2) atom. In the fifth I site, I(5) is bonded in a 4-coordinate geometry to one Fe(1), one Sb(1), one Sb(3), and one Sb(9) atom. In the sixth I site, I(6) is bonded in a 2-coordinate geometry to one Mg(1) and one Sb(2) atom.