Mn9(FeO6)4 crystallizes in the monoclinic Cm space group. There are seven inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(5), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share  a cornercorner with one Fe(3)O4 tetrahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Fe(1)O6 octahedra. In the second Mn site, Mn(2) is bonded to one O(2), one O(6), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share  a cornercorner with one Fe(3)O4 tetrahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Fe(1)O6 octahedra. In the third Mn site, Mn(3) is bonded to one O(4), one O(5), one O(6), one O(7), one O(8), and one O(9) atom to form edge-sharing MnO6 octahedra. In the fourth Mn site, Mn(4) is bonded to one O(11), one O(7), two equivalent O(10), and two equivalent O(9) atoms to form edge-sharing MnO6 octahedra. In the fifth Mn site, Mn(5) is bonded to one O(12), one O(8), two equivalent O(10), and two equivalent O(9) atoms to form edge-sharing MnO6 octahedra. In the sixth Mn site, Mn(6) is bonded to one O(10), one O(11), one O(12), one O(13), one O(14), and one O(15) atom to form MnO6 octahedra that share  a cornercorner with one Fe(3)O4 tetrahedra,  an edgeedge with one Mn(4)O6 octahedra,  an edgeedge with one Mn(5)O6 octahedra,  an edgeedge with one Mn(7)O6 octahedra,  an edgeedge with one Fe(2)O6 octahedra, and edges with two equivalent Mn(6)O6 octahedra. In the seventh Mn site, Mn(7) is bonded to one O(13), one O(18), two equivalent O(15), and two equivalent O(16) atoms to form MnO6 octahedra that share corners with two equivalent Fe(3)O4 tetrahedra, edges with two equivalent Mn(6)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, and edges with two equivalent Fe(2)O6 octahedra. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(16), one O(17), one O(18), one O(2), and one O(3) atom to form FeO6 octahedra that share corners with two equivalent Fe(3)O4 tetrahedra,  an edgeedge with one Mn(1)O6 octahedra,  an edgeedge with one Mn(2)O6 octahedra,  an edgeedge with one Mn(7)O6 octahedra,  an edgeedge with one Fe(2)O6 octahedra, and edges with two equivalent Fe(1)O6 octahedra. In the second Fe site, Fe(2) is bonded to one O(14), one O(17), two equivalent O(15), and two equivalent O(16) atoms to form FeO6 octahedra that share corners with two equivalent Fe(3)O4 tetrahedra, edges with two equivalent Mn(6)O6 octahedra, edges with two equivalent Mn(7)O6 octahedra, and edges with two equivalent Fe(1)O6 octahedra. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), and two equivalent O(15) atoms to form FeO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Mn(2)O6 octahedra, corners with two equivalent Mn(6)O6 octahedra, corners with two equivalent Mn(7)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-61°. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mn(1), one Fe(3), and two equivalent Fe(1) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mn(2), one Fe(3), and two equivalent Fe(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Mn(1), one Mn(2), and one Fe(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Mn(1), one Mn(2), and one Mn(3) atom. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Mn(1) and two equivalent Mn(3) atoms. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Mn(2) and two equivalent Mn(3) atoms. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Mn(4) and two equivalent Mn(3) atoms. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Mn(5) and two equivalent Mn(3) atoms. In the ninth O site, O(9) is bonded in a distorted T-shaped geometry to one Mn(3), one Mn(4), and one Mn(5) atom. In the tenth O site, O(10) is bonded in a distorted trigonal non-coplanar geometry to one Mn(4), one Mn(5), and one Mn(6) atom. In the eleventh O site, O(11) is bonded in a distorted T-shaped geometry to one Mn(4) and two equivalent Mn(6) atoms. In the twelfth O site, O(12) is bonded in a distorted trigonal non-coplanar geometry to one Mn(5) and two equivalent Mn(6) atoms. In the thirteenth O site, O(13) is bonded in a distorted trigonal non-coplanar geometry to one Mn(7) and two equivalent Mn(6) atoms. In the fourteenth O site, O(14) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Mn(6) and one Fe(2) atom. In the fifteenth O site, O(15) is bonded in a rectangular see-saw-like geometry to one Mn(6), one Mn(7), one Fe(2), and one Fe(3) atom. In the sixteenth O site, O(16) is bonded in a distorted T-shaped geometry to one Mn(7), one Fe(1), and one Fe(2) atom. In the seventeenth O site, O(17) is bonded in a distorted T-shaped geometry to one Fe(2) and two equivalent Fe(1) atoms. In the eighteenth O site, O(18) is bonded in a distorted T-shaped geometry to one Mn(7) and two equivalent Fe(1) atoms.
Mn9(FeO6)4 crystallizes in the monoclinic Cm space group. There are seven inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(5), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share  a cornercorner with one Fe(3)O4 tetrahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Fe(1)O6 octahedra. The Mn(1)-O(1) bond length is 2.02 Å. The Mn(1)-O(5) bond length is 1.92 Å. Both Mn(1)-O(3) bond lengths are 1.94 Å. Both Mn(1)-O(4) bond lengths are 1.97 Å. In the second Mn site, Mn(2) is bonded to one O(2), one O(6), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share  a cornercorner with one Fe(3)O4 tetrahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Fe(1)O6 octahedra. The Mn(2)-O(2) bond length is 2.00 Å. The Mn(2)-O(6) bond length is 1.92 Å. Both Mn(2)-O(3) bond lengths are 1.93 Å. Both Mn(2)-O(4) bond lengths are 1.98 Å. In the third Mn site, Mn(3) is bonded to one O(4), one O(5), one O(6), one O(7), one O(8), and one O(9) atom to form edge-sharing MnO6 octahedra. The Mn(3)-O(4) bond length is 1.93 Å. The Mn(3)-O(5) bond length is 1.97 Å. The Mn(3)-O(6) bond length is 1.97 Å. The Mn(3)-O(7) bond length is 1.95 Å. The Mn(3)-O(8) bond length is 1.95 Å. The Mn(3)-O(9) bond length is 1.95 Å. In the fourth Mn site, Mn(4) is bonded to one O(11), one O(7), two equivalent O(10), and two equivalent O(9) atoms to form edge-sharing MnO6 octahedra. The Mn(4)-O(11) bond length is 1.94 Å. The Mn(4)-O(7) bond length is 1.94 Å. Both Mn(4)-O(10) bond lengths are 1.97 Å. Both Mn(4)-O(9) bond lengths are 1.95 Å. In the fifth Mn site, Mn(5) is bonded to one O(12), one O(8), two equivalent O(10), and two equivalent O(9) atoms to form edge-sharing MnO6 octahedra. The Mn(5)-O(12) bond length is 1.94 Å. The Mn(5)-O(8) bond length is 1.95 Å. Both Mn(5)-O(10) bond lengths are 1.96 Å. Both Mn(5)-O(9) bond lengths are 1.95 Å. In the sixth Mn site, Mn(6) is bonded to one O(10), one O(11), one O(12), one O(13), one O(14), and one O(15) atom to form MnO6 octahedra that share  a cornercorner with one Fe(3)O4 tetrahedra,  an edgeedge with one Mn(4)O6 octahedra,  an edgeedge with one Mn(5)O6 octahedra,  an edgeedge with one Mn(7)O6 octahedra,  an edgeedge with one Fe(2)O6 octahedra, and edges with two equivalent Mn(6)O6 octahedra. The Mn(6)-O(10) bond length is 1.92 Å. The Mn(6)-O(11) bond length is 1.96 Å. The Mn(6)-O(12) bond length is 1.95 Å. The Mn(6)-O(13) bond length is 1.95 Å. The Mn(6)-O(14) bond length is 1.92 Å. The Mn(6)-O(15) bond length is 2.01 Å. In the seventh Mn site, Mn(7) is bonded to one O(13), one O(18), two equivalent O(15), and two equivalent O(16) atoms to form MnO6 octahedra that share corners with two equivalent Fe(3)O4 tetrahedra, edges with two equivalent Mn(6)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, and edges with two equivalent Fe(2)O6 octahedra. The Mn(7)-O(13) bond length is 1.96 Å. The Mn(7)-O(18) bond length is 1.88 Å. Both Mn(7)-O(15) bond lengths are 2.05 Å. Both Mn(7)-O(16) bond lengths are 1.87 Å. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(16), one O(17), one O(18), one O(2), and one O(3) atom to form FeO6 octahedra that share corners with two equivalent Fe(3)O4 tetrahedra,  an edgeedge with one Mn(1)O6 octahedra,  an edgeedge with one Mn(2)O6 octahedra,  an edgeedge with one Mn(7)O6 octahedra,  an edgeedge with one Fe(2)O6 octahedra, and edges with two equivalent Fe(1)O6 octahedra. The Fe(1)-O(1) bond length is 2.11 Å. The Fe(1)-O(16) bond length is 2.05 Å. The Fe(1)-O(17) bond length is 1.96 Å. The Fe(1)-O(18) bond length is 1.99 Å. The Fe(1)-O(2) bond length is 2.11 Å. The Fe(1)-O(3) bond length is 2.01 Å. In the second Fe site, Fe(2) is bonded to one O(14), one O(17), two equivalent O(15), and two equivalent O(16) atoms to form FeO6 octahedra that share corners with two equivalent Fe(3)O4 tetrahedra, edges with two equivalent Mn(6)O6 octahedra, edges with two equivalent Mn(7)O6 octahedra, and edges with two equivalent Fe(1)O6 octahedra. The Fe(2)-O(14) bond length is 2.02 Å. The Fe(2)-O(17) bond length is 1.98 Å. Both Fe(2)-O(15) bond lengths are 2.12 Å. Both Fe(2)-O(16) bond lengths are 2.01 Å. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), and two equivalent O(15) atoms to form FeO4 tetrahedra that share  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Mn(2)O6 octahedra, corners with two equivalent Mn(6)O6 octahedra, corners with two equivalent Mn(7)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, and corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-61°. The Fe(3)-O(1) bond length is 1.92 Å. The Fe(3)-O(2) bond length is 1.90 Å. Both Fe(3)-O(15) bond lengths are 1.94 Å. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mn(1), one Fe(3), and two equivalent Fe(1) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mn(2), one Fe(3), and two equivalent Fe(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Mn(1), one Mn(2), and one Fe(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Mn(1), one Mn(2), and one Mn(3) atom. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Mn(1) and two equivalent Mn(3) atoms. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Mn(2) and two equivalent Mn(3) atoms. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Mn(4) and two equivalent Mn(3) atoms. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Mn(5) and two equivalent Mn(3) atoms. In the ninth O site, O(9) is bonded in a distorted T-shaped geometry to one Mn(3), one Mn(4), and one Mn(5) atom. In the tenth O site, O(10) is bonded in a distorted trigonal non-coplanar geometry to one Mn(4), one Mn(5), and one Mn(6) atom. In the eleventh O site, O(11) is bonded in a distorted T-shaped geometry to one Mn(4) and two equivalent Mn(6) atoms. In the twelfth O site, O(12) is bonded in a distorted trigonal non-coplanar geometry to one Mn(5) and two equivalent Mn(6) atoms. In the thirteenth O site, O(13) is bonded in a distorted trigonal non-coplanar geometry to one Mn(7) and two equivalent Mn(6) atoms. In the fourteenth O site, O(14) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Mn(6) and one Fe(2) atom. In the fifteenth O site, O(15) is bonded in a rectangular see-saw-like geometry to one Mn(6), one Mn(7), one Fe(2), and one Fe(3) atom. In the sixteenth O site, O(16) is bonded in a distorted T-shaped geometry to one Mn(7), one Fe(1), and one Fe(2) atom. In the seventeenth O site, O(17) is bonded in a distorted T-shaped geometry to one Fe(2) and two equivalent Fe(1) atoms. In the eighteenth O site, O(18) is bonded in a distorted T-shaped geometry to one Mn(7) and two equivalent Fe(1) atoms.