MgCr2Mn5O12 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(10), one O(11), one O(2), one O(3), one O(6), and one O(7) atom to form MgO6 octahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Mn(4)O6 octahedra,  a cornercorner with one Mn(5)O6 octahedra,  an edgeedge with one Cr(1)O6 octahedra,  an edgeedge with one Cr(2)O6 octahedra,  an edgeedge with one Mn(1)O6 octahedra,  an edgeedge with one Mn(4)O6 octahedra,  an edgeedge with one Mn(5)O6 octahedra, and edges with three equivalent Mn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-25°. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(10), one O(2), one O(5), one O(6), and one O(9) atom to form CrO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Mn(2)O6 octahedra,  a cornercorner with one Mn(3)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Mn(2)O6 octahedra,  an edgeedge with one Mn(3)O6 octahedra, and edges with three equivalent Mn(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-28°. In the second Cr site, Cr(2) is bonded to one O(11), one O(12), one O(3), one O(4), one O(7), and one O(8) atom to form CrO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Mn(2)O6 octahedra,  a cornercorner with one Mn(3)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Mn(2)O6 octahedra,  an edgeedge with one Mn(3)O6 octahedra, edges with three equivalent Mn(1)O6 octahedra, and edges with three equivalent Mn(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-19°. There are five inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(11), one O(12), one O(3), one O(4), one O(7), and one O(8) atom to form distorted MnO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Mn(2)O6 octahedra,  a cornercorner with one Mn(3)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Mn(2)O6 octahedra,  an edgeedge with one Mn(3)O6 octahedra, edges with three equivalent Cr(2)O6 octahedra, and edges with three equivalent Mn(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-21°. In the second Mn site, Mn(2) is bonded to one O(1), one O(12), one O(4), one O(5), one O(8), and one O(9) atom to form distorted MnO6 octahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Mn(4)O6 octahedra,  a cornercorner with one Mn(5)O6 octahedra,  an edgeedge with one Cr(1)O6 octahedra,  an edgeedge with one Cr(2)O6 octahedra,  an edgeedge with one Mn(1)O6 octahedra,  an edgeedge with one Mn(4)O6 octahedra, and  an edgeedge with one Mn(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 12-28°. In the third Mn site, Mn(3) is bonded to one O(10), one O(11), one O(2), one O(3), one O(6), and one O(7) atom to form distorted MnO6 octahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Mn(4)O6 octahedra,  a cornercorner with one Mn(5)O6 octahedra,  an edgeedge with one Cr(1)O6 octahedra,  an edgeedge with one Cr(2)O6 octahedra,  an edgeedge with one Mn(1)O6 octahedra,  an edgeedge with one Mn(4)O6 octahedra,  an edgeedge with one Mn(5)O6 octahedra, and edges with three equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-24°. In the fourth Mn site, Mn(4) is bonded to one O(11), one O(12), one O(3), one O(4), one O(7), and one O(8) atom to form distorted MnO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Mn(2)O6 octahedra,  a cornercorner with one Mn(3)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Mn(2)O6 octahedra,  an edgeedge with one Mn(3)O6 octahedra, edges with three equivalent Cr(2)O6 octahedra, and edges with three equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-13°. In the fifth Mn site, Mn(5) is bonded to one O(1), one O(10), one O(2), one O(5), one O(6), and one O(9) atom to form MnO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Mn(2)O6 octahedra,  a cornercorner with one Mn(3)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Mn(2)O6 octahedra,  an edgeedge with one Mn(3)O6 octahedra, and edges with three equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-25°. There are twelve 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(5) atom. In the second O site, O(2) is bonded to one Mg(1), one Cr(1), one Mn(3), and one Mn(5) atom to form a mixture of corner and edge-sharing OMgMn2Cr trigonal pyramids. In the third O site, O(3) is bonded to one Mg(1), one Cr(2), one Mn(1), one Mn(3), and one Mn(4) atom to form distorted OMgMn3Cr square pyramids that share  a cornercorner with one O(11)MgMn3Cr square pyramid,  a cornercorner with one O(7)MgMn3Cr square pyramid,  a cornercorner with one O(12)Mn3Cr trigonal pyramid, edges with two equivalent O(11)MgMn3Cr square pyramids, edges with two equivalent O(7)MgMn3Cr square pyramids,  an edgeedge with one O(2)MgMn2Cr trigonal pyramid, and  an edgeedge with one O(12)Mn3Cr trigonal pyramid. In the fourth O site, O(4) is bonded in a see-saw-like geometry to one Cr(2), one Mn(1), one Mn(2), and one Mn(4) 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(5) atom. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Cr(1), one Mn(3), and one Mn(5) atom. In the seventh O site, O(7) is bonded to one Mg(1), one Cr(2), one Mn(1), one Mn(3), and one Mn(4) atom to form distorted OMgMn3Cr square pyramids that share  a cornercorner with one O(11)MgMn3Cr square pyramid,  a cornercorner with one O(3)MgMn3Cr square pyramid,  a cornercorner with one O(12)Mn3Cr trigonal pyramid, corners with two equivalent O(2)MgMn2Cr trigonal pyramids, edges with two equivalent O(11)MgMn3Cr square pyramids, edges with two equivalent O(3)MgMn3Cr square pyramids, and  an edgeedge with one O(12)Mn3Cr trigonal pyramid. In the eighth O site, O(8) is bonded in a distorted see-saw-like geometry to one Cr(2), one Mn(1), one Mn(2), and one Mn(4) atom. In the ninth O site, O(9) is bonded in a T-shaped geometry to one Cr(1), one Mn(2), and one Mn(5) atom. In the tenth O site, O(10) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Cr(1), one Mn(3), and one Mn(5) atom. In the eleventh O site, O(11) is bonded to one Mg(1), one Cr(2), one Mn(1), one Mn(3), and one Mn(4) atom to form distorted OMgMn3Cr square pyramids that share  a cornercorner with one O(3)MgMn3Cr square pyramid,  a cornercorner with one O(7)MgMn3Cr square pyramid,  a cornercorner with one O(12)Mn3Cr trigonal pyramid, corners with two equivalent O(2)MgMn2Cr trigonal pyramids, edges with two equivalent O(3)MgMn3Cr square pyramids, edges with two equivalent O(7)MgMn3Cr square pyramids, and  an edgeedge with one O(12)Mn3Cr trigonal pyramid. In the twelfth O site, O(12) is bonded to one Cr(2), one Mn(1), one Mn(2), and one Mn(4) atom to form a mixture of distorted corner and edge-sharing OMn3Cr trigonal pyramids.
MgCr2Mn5O12 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(10), one O(11), one O(2), one O(3), one O(6), and one O(7) atom to form MgO6 octahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Mn(4)O6 octahedra,  a cornercorner with one Mn(5)O6 octahedra,  an edgeedge with one Cr(1)O6 octahedra,  an edgeedge with one Cr(2)O6 octahedra,  an edgeedge with one Mn(1)O6 octahedra,  an edgeedge with one Mn(4)O6 octahedra,  an edgeedge with one Mn(5)O6 octahedra, and edges with three equivalent Mn(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-25°. The Mg(1)-O(10) bond length is 2.03 Å. The Mg(1)-O(11) bond length is 2.17 Å. The Mg(1)-O(2) bond length is 2.02 Å. The Mg(1)-O(3) bond length is 2.19 Å. The Mg(1)-O(6) bond length is 2.07 Å. The Mg(1)-O(7) bond length is 2.20 Å. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(10), one O(2), one O(5), one O(6), and one O(9) atom to form CrO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Mn(2)O6 octahedra,  a cornercorner with one Mn(3)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Mn(2)O6 octahedra,  an edgeedge with one Mn(3)O6 octahedra, and edges with three equivalent Mn(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 6-28°. The Cr(1)-O(1) bond length is 2.02 Å. The Cr(1)-O(10) bond length is 2.11 Å. The Cr(1)-O(2) bond length is 2.06 Å. The Cr(1)-O(5) bond length is 1.91 Å. The Cr(1)-O(6) bond length is 2.03 Å. The Cr(1)-O(9) bond length is 1.98 Å. In the second Cr site, Cr(2) is bonded to one O(11), one O(12), one O(3), one O(4), one O(7), and one O(8) atom to form CrO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Mn(2)O6 octahedra,  a cornercorner with one Mn(3)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Mn(2)O6 octahedra,  an edgeedge with one Mn(3)O6 octahedra, edges with three equivalent Mn(1)O6 octahedra, and edges with three equivalent Mn(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-19°. The Cr(2)-O(11) bond length is 2.13 Å. The Cr(2)-O(12) bond length is 2.00 Å. The Cr(2)-O(3) bond length is 2.08 Å. The Cr(2)-O(4) bond length is 2.06 Å. The Cr(2)-O(7) bond length is 2.03 Å. The Cr(2)-O(8) bond length is 1.96 Å. There are five inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(11), one O(12), one O(3), one O(4), one O(7), and one O(8) atom to form distorted MnO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Mn(2)O6 octahedra,  a cornercorner with one Mn(3)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Mn(2)O6 octahedra,  an edgeedge with one Mn(3)O6 octahedra, edges with three equivalent Cr(2)O6 octahedra, and edges with three equivalent Mn(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-21°. The Mn(1)-O(11) bond length is 2.47 Å. The Mn(1)-O(12) bond length is 2.05 Å. The Mn(1)-O(3) bond length is 2.01 Å. The Mn(1)-O(4) bond length is 2.13 Å. The Mn(1)-O(7) bond length is 1.98 Å. The Mn(1)-O(8) bond length is 1.87 Å. In the second Mn site, Mn(2) is bonded to one O(1), one O(12), one O(4), one O(5), one O(8), and one O(9) atom to form distorted MnO6 octahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Mn(4)O6 octahedra,  a cornercorner with one Mn(5)O6 octahedra,  an edgeedge with one Cr(1)O6 octahedra,  an edgeedge with one Cr(2)O6 octahedra,  an edgeedge with one Mn(1)O6 octahedra,  an edgeedge with one Mn(4)O6 octahedra, and  an edgeedge with one Mn(5)O6 octahedra. The corner-sharing octahedral tilt angles range from 12-28°. The Mn(2)-O(1) bond length is 1.96 Å. The Mn(2)-O(12) bond length is 2.21 Å. The Mn(2)-O(4) bond length is 2.13 Å. The Mn(2)-O(5) bond length is 2.12 Å. The Mn(2)-O(8) bond length is 2.44 Å. The Mn(2)-O(9) bond length is 1.93 Å. In the third Mn site, Mn(3) is bonded to one O(10), one O(11), one O(2), one O(3), one O(6), and one O(7) atom to form distorted MnO6 octahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra,  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Mn(4)O6 octahedra,  a cornercorner with one Mn(5)O6 octahedra,  an edgeedge with one Cr(1)O6 octahedra,  an edgeedge with one Cr(2)O6 octahedra,  an edgeedge with one Mn(1)O6 octahedra,  an edgeedge with one Mn(4)O6 octahedra,  an edgeedge with one Mn(5)O6 octahedra, and edges with three equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-24°. The Mn(3)-O(10) bond length is 1.94 Å. The Mn(3)-O(11) bond length is 2.03 Å. The Mn(3)-O(2) bond length is 1.92 Å. The Mn(3)-O(3) bond length is 2.05 Å. The Mn(3)-O(6) bond length is 2.16 Å. The Mn(3)-O(7) bond length is 2.50 Å. In the fourth Mn site, Mn(4) is bonded to one O(11), one O(12), one O(3), one O(4), one O(7), and one O(8) atom to form distorted MnO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Mn(2)O6 octahedra,  a cornercorner with one Mn(3)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Mn(2)O6 octahedra,  an edgeedge with one Mn(3)O6 octahedra, edges with three equivalent Cr(2)O6 octahedra, and edges with three equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-13°. The Mn(4)-O(11) bond length is 1.97 Å. The Mn(4)-O(12) bond length is 1.94 Å. The Mn(4)-O(3) bond length is 2.48 Å. The Mn(4)-O(4) bond length is 1.91 Å. The Mn(4)-O(7) bond length is 1.99 Å. The Mn(4)-O(8) bond length is 2.18 Å. In the fifth Mn site, Mn(5) is bonded to one O(1), one O(10), one O(2), one O(5), one O(6), and one O(9) atom to form MnO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one Mn(2)O6 octahedra,  a cornercorner with one Mn(3)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra,  an edgeedge with one Mn(2)O6 octahedra,  an edgeedge with one Mn(3)O6 octahedra, and edges with three equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 1-25°. The Mn(5)-O(1) bond length is 1.93 Å. The Mn(5)-O(10) bond length is 2.04 Å. The Mn(5)-O(2) bond length is 2.00 Å. The Mn(5)-O(5) bond length is 1.91 Å. The Mn(5)-O(6) bond length is 2.02 Å. The Mn(5)-O(9) bond length is 1.94 Å. There are twelve 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(5) atom. In the second O site, O(2) is bonded to one Mg(1), one Cr(1), one Mn(3), and one Mn(5) atom to form a mixture of corner and edge-sharing OMgMn2Cr trigonal pyramids. In the third O site, O(3) is bonded to one Mg(1), one Cr(2), one Mn(1), one Mn(3), and one Mn(4) atom to form distorted OMgMn3Cr square pyramids that share  a cornercorner with one O(11)MgMn3Cr square pyramid,  a cornercorner with one O(7)MgMn3Cr square pyramid,  a cornercorner with one O(12)Mn3Cr trigonal pyramid, edges with two equivalent O(11)MgMn3Cr square pyramids, edges with two equivalent O(7)MgMn3Cr square pyramids,  an edgeedge with one O(2)MgMn2Cr trigonal pyramid, and  an edgeedge with one O(12)Mn3Cr trigonal pyramid. In the fourth O site, O(4) is bonded in a see-saw-like geometry to one Cr(2), one Mn(1), one Mn(2), and one Mn(4) 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(5) atom. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Cr(1), one Mn(3), and one Mn(5) atom. In the seventh O site, O(7) is bonded to one Mg(1), one Cr(2), one Mn(1), one Mn(3), and one Mn(4) atom to form distorted OMgMn3Cr square pyramids that share  a cornercorner with one O(11)MgMn3Cr square pyramid,  a cornercorner with one O(3)MgMn3Cr square pyramid,  a cornercorner with one O(12)Mn3Cr trigonal pyramid, corners with two equivalent O(2)MgMn2Cr trigonal pyramids, edges with two equivalent O(11)MgMn3Cr square pyramids, edges with two equivalent O(3)MgMn3Cr square pyramids, and  an edgeedge with one O(12)Mn3Cr trigonal pyramid. In the eighth O site, O(8) is bonded in a distorted see-saw-like geometry to one Cr(2), one Mn(1), one Mn(2), and one Mn(4) atom. In the ninth O site, O(9) is bonded in a T-shaped geometry to one Cr(1), one Mn(2), and one Mn(5) atom. In the tenth O site, O(10) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Cr(1), one Mn(3), and one Mn(5) atom. In the eleventh O site, O(11) is bonded to one Mg(1), one Cr(2), one Mn(1), one Mn(3), and one Mn(4) atom to form distorted OMgMn3Cr square pyramids that share  a cornercorner with one O(3)MgMn3Cr square pyramid,  a cornercorner with one O(7)MgMn3Cr square pyramid,  a cornercorner with one O(12)Mn3Cr trigonal pyramid, corners with two equivalent O(2)MgMn2Cr trigonal pyramids, edges with two equivalent O(3)MgMn3Cr square pyramids, edges with two equivalent O(7)MgMn3Cr square pyramids, and  an edgeedge with one O(12)Mn3Cr trigonal pyramid. In the twelfth O site, O(12) is bonded to one Cr(2), one Mn(1), one Mn(2), and one Mn(4) atom to form a mixture of distorted corner and edge-sharing OMn3Cr trigonal pyramids.