BaMn2Fe4O11 crystallizes in the monoclinic Cc space group. Ba(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), two equivalent O(10), two equivalent O(11), and two equivalent O(9) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ba(1)O12 cuboctahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, faces with three equivalent Fe(1)O6 octahedra, and faces with three equivalent Fe(2)O6 octahedra. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(3), one O(4), one O(6), one O(7), and one O(8) atom to form MnO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, edges with two equivalent Ba(1)O12 cuboctahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-54°. In the second Mn site, Mn(2) is bonded to one O(1), one O(2), one O(4), one O(5), one O(7), and one O(8) atom to form MnO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, edges with two equivalent Ba(1)O12 cuboctahedra, edges with two equivalent Mn(1)O6 octahedra, and edges with two equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-54°. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(10), one O(11), one O(2), one O(3), and one O(9) atom to form distorted FeO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, faces with three equivalent Ba(1)O12 cuboctahedra, and  a faceface with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-56°. In the second Fe site, Fe(2) is bonded to one O(10), one O(11), one O(4), one O(5), one O(6), and one O(9) atom to form FeO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, faces with three equivalent Ba(1)O12 cuboctahedra, and  a faceface with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-55°. In the third Fe site, Fe(3) is bonded to one O(2), one O(3), one O(5), one O(6), one O(7), and one O(8) atom to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, edges with two equivalent Ba(1)O12 cuboctahedra, edges with two equivalent Mn(1)O6 octahedra, and edges with two equivalent Mn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-56°. In the fourth Fe site, Fe(4) is bonded in a 5-coordinate geometry to one O(10), one O(11), one O(7), one O(8), and one O(9) atom. There are eleven inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to one Ba(1), one Mn(2), one Fe(2), and one Fe(3) atom. In the second O site, O(6) is bonded in a 3-coordinate geometry to one Ba(1), one Mn(1), one Fe(2), and one Fe(3) atom. In the third O site, O(7) is bonded in a 4-coordinate geometry to one Mn(1), one Mn(2), one Fe(3), and one Fe(4) atom. In the fourth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Mn(1), one Mn(2), one Fe(3), and one Fe(4) atom. In the fifth O site, O(9) is bonded in a 3-coordinate geometry to two equivalent Ba(1), one Fe(1), one Fe(2), and one Fe(4) atom. In the sixth O site, O(10) is bonded in a 3-coordinate geometry to two equivalent Ba(1), one Fe(1), one Fe(2), and one Fe(4) atom. In the seventh O site, O(11) is bonded in a 3-coordinate geometry to two equivalent Ba(1), one Fe(1), one Fe(2), and one Fe(4) atom. In the eighth O site, O(1) is bonded in a 4-coordinate geometry to one Ba(1), one Mn(1), one Mn(2), and one Fe(1) atom. In the ninth O site, O(2) is bonded in a 4-coordinate geometry to one Ba(1), one Mn(2), one Fe(1), and one Fe(3) atom. In the tenth O site, O(3) is bonded in a 4-coordinate geometry to one Ba(1), one Mn(1), one Fe(1), and one Fe(3) atom. In the eleventh O site, O(4) is bonded in a 3-coordinate geometry to one Ba(1), one Mn(1), one Mn(2), and one Fe(2) atom.
BaMn2Fe4O11 crystallizes in the monoclinic Cc space group. Ba(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), two equivalent O(10), two equivalent O(11), and two equivalent O(9) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ba(1)O12 cuboctahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, faces with three equivalent Fe(1)O6 octahedra, and faces with three equivalent Fe(2)O6 octahedra. The Ba(1)-O(1) bond length is 2.84 Å. The Ba(1)-O(2) bond length is 2.83 Å. The Ba(1)-O(3) bond length is 2.82 Å. The Ba(1)-O(4) bond length is 2.88 Å. The Ba(1)-O(5) bond length is 2.87 Å. The Ba(1)-O(6) bond length is 2.86 Å. Both Ba(1)-O(10) bond lengths are 2.95 Å. There is one shorter (2.95 Å) and one longer (2.96 Å) Ba(1)-O(11) bond length. There is one shorter (2.94 Å) and one longer (2.95 Å) Ba(1)-O(9) bond length. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(3), one O(4), one O(6), one O(7), and one O(8) atom to form MnO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, edges with two equivalent Ba(1)O12 cuboctahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-54°. The Mn(1)-O(1) bond length is 1.96 Å. The Mn(1)-O(3) bond length is 1.93 Å. The Mn(1)-O(4) bond length is 1.95 Å. The Mn(1)-O(6) bond length is 1.93 Å. The Mn(1)-O(7) bond length is 1.95 Å. The Mn(1)-O(8) bond length is 1.99 Å. In the second Mn site, Mn(2) is bonded to one O(1), one O(2), one O(4), one O(5), one O(7), and one O(8) atom to form MnO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, edges with two equivalent Ba(1)O12 cuboctahedra, edges with two equivalent Mn(1)O6 octahedra, and edges with two equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-54°. The Mn(2)-O(1) bond length is 1.96 Å. The Mn(2)-O(2) bond length is 1.93 Å. The Mn(2)-O(4) bond length is 1.95 Å. The Mn(2)-O(5) bond length is 1.93 Å. The Mn(2)-O(7) bond length is 1.95 Å. The Mn(2)-O(8) bond length is 1.99 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(10), one O(11), one O(2), one O(3), and one O(9) atom to form distorted FeO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, faces with three equivalent Ba(1)O12 cuboctahedra, and  a faceface with one Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-56°. The Fe(1)-O(1) bond length is 2.05 Å. The Fe(1)-O(10) bond length is 2.12 Å. The Fe(1)-O(11) bond length is 2.13 Å. The Fe(1)-O(2) bond length is 1.99 Å. The Fe(1)-O(3) bond length is 1.98 Å. The Fe(1)-O(9) bond length is 2.10 Å. In the second Fe site, Fe(2) is bonded to one O(10), one O(11), one O(4), one O(5), one O(6), and one O(9) atom to form FeO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with two equivalent Mn(2)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, faces with three equivalent Ba(1)O12 cuboctahedra, and  a faceface with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-55°. The Fe(2)-O(10) bond length is 2.07 Å. The Fe(2)-O(11) bond length is 2.10 Å. The Fe(2)-O(4) bond length is 2.05 Å. The Fe(2)-O(5) bond length is 1.99 Å. The Fe(2)-O(6) bond length is 1.99 Å. The Fe(2)-O(9) bond length is 2.10 Å. In the third Fe site, Fe(3) is bonded to one O(2), one O(3), one O(5), one O(6), one O(7), and one O(8) atom to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, edges with two equivalent Ba(1)O12 cuboctahedra, edges with two equivalent Mn(1)O6 octahedra, and edges with two equivalent Mn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-56°. The Fe(3)-O(2) bond length is 2.02 Å. The Fe(3)-O(3) bond length is 2.02 Å. The Fe(3)-O(5) bond length is 2.01 Å. The Fe(3)-O(6) bond length is 2.01 Å. The Fe(3)-O(7) bond length is 2.05 Å. The Fe(3)-O(8) bond length is 2.08 Å. In the fourth Fe site, Fe(4) is bonded in a 5-coordinate geometry to one O(10), one O(11), one O(7), one O(8), and one O(9) atom. The Fe(4)-O(10) bond length is 1.88 Å. The Fe(4)-O(11) bond length is 1.88 Å. The Fe(4)-O(7) bond length is 2.62 Å. The Fe(4)-O(8) bond length is 2.08 Å. The Fe(4)-O(9) bond length is 1.88 Å. There are eleven inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to one Ba(1), one Mn(2), one Fe(2), and one Fe(3) atom. In the second O site, O(6) is bonded in a 3-coordinate geometry to one Ba(1), one Mn(1), one Fe(2), and one Fe(3) atom. In the third O site, O(7) is bonded in a 4-coordinate geometry to one Mn(1), one Mn(2), one Fe(3), and one Fe(4) atom. In the fourth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Mn(1), one Mn(2), one Fe(3), and one Fe(4) atom. In the fifth O site, O(9) is bonded in a 3-coordinate geometry to two equivalent Ba(1), one Fe(1), one Fe(2), and one Fe(4) atom. In the sixth O site, O(10) is bonded in a 3-coordinate geometry to two equivalent Ba(1), one Fe(1), one Fe(2), and one Fe(4) atom. In the seventh O site, O(11) is bonded in a 3-coordinate geometry to two equivalent Ba(1), one Fe(1), one Fe(2), and one Fe(4) atom. In the eighth O site, O(1) is bonded in a 4-coordinate geometry to one Ba(1), one Mn(1), one Mn(2), and one Fe(1) atom. In the ninth O site, O(2) is bonded in a 4-coordinate geometry to one Ba(1), one Mn(2), one Fe(1), and one Fe(3) atom. In the tenth O site, O(3) is bonded in a 4-coordinate geometry to one Ba(1), one Mn(1), one Fe(1), and one Fe(3) atom. In the eleventh O site, O(4) is bonded in a 3-coordinate geometry to one Ba(1), one Mn(1), one Mn(2), and one Fe(2) atom.