Mn5FeO12 is trigonal omega-derived structured and crystallizes in the monoclinic C2/c space group. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form MnO6 octahedra that share 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(1), one O(3), one O(4), one O(5), and two equivalent O(6) atoms to form MnO6 octahedra that share  an edgeedge with one Mn(1)O6 octahedra,  an edgeedge with one Mn(2)O6 octahedra,  an edgeedge with one Fe(1)O6 octahedra, and edges with three equivalent Mn(3)O6 octahedra. In the third Mn site, Mn(3) is bonded to one O(2), one O(3), one O(4), one O(6), and two equivalent O(5) atoms to form MnO6 octahedra that share  an edgeedge with one Mn(1)O6 octahedra,  an edgeedge with one Mn(3)O6 octahedra,  an edgeedge with one Fe(1)O6 octahedra, and edges with three equivalent Mn(2)O6 octahedra. Fe(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Mn(3)O6 octahedra. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Mn(1), one Mn(2), and one Fe(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Mn(1), one Mn(3), and one Fe(1) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Mn(2), one Mn(3), 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 T-shaped geometry to one Mn(2) 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(3) and two equivalent Mn(2) atoms.
Mn5FeO12 is trigonal omega-derived structured and crystallizes in the monoclinic C2/c space group. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form MnO6 octahedra that share 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. Both Mn(1)-O(1) bond lengths are 1.94 Å. Both Mn(1)-O(2) bond lengths are 1.93 Å. Both Mn(1)-O(4) bond lengths are 1.95 Å. In the second Mn site, Mn(2) is bonded to one O(1), one O(3), one O(4), one O(5), and two equivalent O(6) atoms to form MnO6 octahedra that share  an edgeedge with one Mn(1)O6 octahedra,  an edgeedge with one Mn(2)O6 octahedra,  an edgeedge with one Fe(1)O6 octahedra, and edges with three equivalent Mn(3)O6 octahedra. The Mn(2)-O(1) bond length is 1.94 Å. The Mn(2)-O(3) bond length is 1.94 Å. The Mn(2)-O(4) bond length is 1.95 Å. The Mn(2)-O(5) bond length is 1.95 Å. Both Mn(2)-O(6) bond lengths are 1.95 Å. In the third Mn site, Mn(3) is bonded to one O(2), one O(3), one O(4), one O(6), and two equivalent O(5) atoms to form MnO6 octahedra that share  an edgeedge with one Mn(1)O6 octahedra,  an edgeedge with one Mn(3)O6 octahedra,  an edgeedge with one Fe(1)O6 octahedra, and edges with three equivalent Mn(2)O6 octahedra. The Mn(3)-O(2) bond length is 1.94 Å. The Mn(3)-O(3) bond length is 1.94 Å. The Mn(3)-O(4) bond length is 1.94 Å. The Mn(3)-O(6) bond length is 1.95 Å. There is one shorter (1.94 Å) and one longer (1.95 Å) Mn(3)-O(5) bond length. Fe(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Mn(3)O6 octahedra. Both Fe(1)-O(1) bond lengths are 2.01 Å. Both Fe(1)-O(2) bond lengths are 1.99 Å. Both Fe(1)-O(3) bond lengths are 2.00 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Mn(1), one Mn(2), and one Fe(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Mn(1), one Mn(3), and one Fe(1) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Mn(2), one Mn(3), 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 T-shaped geometry to one Mn(2) 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(3) and two equivalent Mn(2) atoms.