Cr2Mn5O12 crystallizes in the monoclinic C2 space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form CrO6 octahedra that share edges with three equivalent Mn(4)O6 octahedra. In the second Cr site, Cr(2) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form CrO6 octahedra that share edges with three equivalent Mn(1)O6 octahedra and edges with three equivalent Mn(3)O6 octahedra. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form MnO6 octahedra that share edges with three equivalent Cr(2)O6 octahedra and edges with three equivalent Mn(3)O6 octahedra. In the second Mn site, Mn(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. In the third Mn site, Mn(3) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form MnO6 octahedra that share edges with three equivalent Cr(2)O6 octahedra and edges with three equivalent Mn(1)O6 octahedra. In the fourth Mn site, Mn(4) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form MnO6 octahedra that share edges with three equivalent Cr(1)O6 octahedra. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Cr(1), one Mn(2), and one Mn(4) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Cr(2), one Mn(1), one Mn(2), and one Mn(3) atom. In the third O site, O(3) is bonded in a T-shaped geometry to one Cr(1), one Mn(2), and one Mn(4) atom. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Cr(2), one Mn(1), one Mn(2), and one Mn(3) atom. In the fifth O site, O(5) is bonded in a T-shaped geometry to one Cr(1), one Mn(2), and one Mn(4) atom. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to one Cr(2), one Mn(1), one Mn(2), and one Mn(3) atom.
Cr2Mn5O12 crystallizes in the monoclinic C2 space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form CrO6 octahedra that share edges with three equivalent Mn(4)O6 octahedra. Both Cr(1)-O(1) bond lengths are 2.02 Å. Both Cr(1)-O(3) bond lengths are 1.87 Å. Both Cr(1)-O(5) bond lengths are 1.94 Å. In the second Cr site, Cr(2) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form CrO6 octahedra that share edges with three equivalent Mn(1)O6 octahedra and edges with three equivalent Mn(3)O6 octahedra. Both Cr(2)-O(2) bond lengths are 2.07 Å. Both Cr(2)-O(4) bond lengths are 1.98 Å. Both Cr(2)-O(6) bond lengths are 2.02 Å. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form MnO6 octahedra that share edges with three equivalent Cr(2)O6 octahedra and edges with three equivalent Mn(3)O6 octahedra. Both Mn(1)-O(2) bond lengths are 2.11 Å. Both Mn(1)-O(4) bond lengths are 1.90 Å. Both Mn(1)-O(6) bond lengths are 2.13 Å. In the second Mn site, Mn(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. The Mn(2)-O(1) bond length is 1.95 Å. The Mn(2)-O(2) bond length is 2.08 Å. The Mn(2)-O(3) bond length is 2.08 Å. The Mn(2)-O(4) bond length is 2.59 Å. The Mn(2)-O(5) bond length is 1.92 Å. The Mn(2)-O(6) bond length is 2.11 Å. In the third Mn site, Mn(3) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form MnO6 octahedra that share edges with three equivalent Cr(2)O6 octahedra and edges with three equivalent Mn(1)O6 octahedra. Both Mn(3)-O(2) bond lengths are 1.93 Å. Both Mn(3)-O(4) bond lengths are 1.96 Å. Both Mn(3)-O(6) bond lengths are 1.92 Å. In the fourth Mn site, Mn(4) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form MnO6 octahedra that share edges with three equivalent Cr(1)O6 octahedra. Both Mn(4)-O(1) bond lengths are 1.93 Å. Both Mn(4)-O(3) bond lengths are 1.94 Å. Both Mn(4)-O(5) bond lengths are 1.97 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Cr(1), one Mn(2), and one Mn(4) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Cr(2), one Mn(1), one Mn(2), and one Mn(3) atom. In the third O site, O(3) is bonded in a T-shaped geometry to one Cr(1), one Mn(2), and one Mn(4) atom. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Cr(2), one Mn(1), one Mn(2), and one Mn(3) atom. In the fifth O site, O(5) is bonded in a T-shaped geometry to one Cr(1), one Mn(2), and one Mn(4) atom. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to one Cr(2), one Mn(1), one Mn(2), and one Mn(3) atom.