MgMn3Cd2O8 is Hausmannite-derived structured and crystallizes in the triclinic P-1 space group. Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with four equivalent Mn(1)O6 octahedra, corners with four equivalent Mn(2)O6 octahedra, corners with four equivalent Cd(1)O4 tetrahedra, and faces with two equivalent Mn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-62°. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share corners with four equivalent Mg(1)O6 octahedra, corners with six equivalent Cd(1)O4 tetrahedra, and edges with four equivalent Mn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-40°. In the second Mn site, Mn(2) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form distorted MnO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with five equivalent Cd(1)O4 tetrahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and  a faceface with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-62°. Cd(1) is bonded to one O(1), one O(4), and two equivalent O(3) atoms to form distorted CdO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with three equivalent Mn(1)O6 octahedra, corners with five equivalent Mn(2)O6 octahedra, and  an edgeedge with one Cd(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-87°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), two equivalent Mn(2), and one Cd(1) atom to form distorted OMgMn2Cd tetrahedra that share  a cornercorner with one O(1)MgMn2Cd tetrahedra, corners with four equivalent O(2)MgMn3 trigonal pyramids, corners with four equivalent O(3)Mn2Cd2 trigonal pyramids,  an edgeedge with one O(1)MgMn2Cd tetrahedra, and  an edgeedge with one O(2)MgMn3 trigonal pyramid. In the second O site, O(2) is bonded to one Mg(1), one Mn(1), and two equivalent Mn(2) atoms to form distorted OMgMn3 trigonal pyramids that share corners with four equivalent O(1)MgMn2Cd tetrahedra, corners with two equivalent O(2)MgMn3 trigonal pyramids, corners with two equivalent O(3)Mn2Cd2 trigonal pyramids,  an edgeedge with one O(1)MgMn2Cd tetrahedra,  an edgeedge with one O(2)MgMn3 trigonal pyramid, and  an edgeedge with one O(3)Mn2Cd2 trigonal pyramid. In the third O site, O(3) is bonded to one Mn(1), one Mn(2), and two equivalent Cd(1) atoms to form distorted OMn2Cd2 trigonal pyramids that share corners with four equivalent O(1)MgMn2Cd tetrahedra,  a cornercorner with one O(3)Mn2Cd2 trigonal pyramid, corners with two equivalent O(2)MgMn3 trigonal pyramids,  an edgeedge with one O(2)MgMn3 trigonal pyramid, and  an edgeedge with one O(3)Mn2Cd2 trigonal pyramid. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Mg(1), one Mn(1), one Mn(2), and one Cd(1) atom.
MgMn3Cd2O8 is Hausmannite-derived structured and crystallizes in the triclinic P-1 space group. Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with four equivalent Mn(1)O6 octahedra, corners with four equivalent Mn(2)O6 octahedra, corners with four equivalent Cd(1)O4 tetrahedra, and faces with two equivalent Mn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-62°. Both Mg(1)-O(1) bond lengths are 2.09 Å. Both Mg(1)-O(2) bond lengths are 2.09 Å. Both Mg(1)-O(4) bond lengths are 2.26 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form MnO6 octahedra that share corners with four equivalent Mg(1)O6 octahedra, corners with six equivalent Cd(1)O4 tetrahedra, and edges with four equivalent Mn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-40°. Both Mn(1)-O(2) bond lengths are 1.95 Å. Both Mn(1)-O(3) bond lengths are 1.92 Å. Both Mn(1)-O(4) bond lengths are 2.01 Å. In the second Mn site, Mn(2) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form distorted MnO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with five equivalent Cd(1)O4 tetrahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and  a faceface with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-62°. The Mn(2)-O(3) bond length is 1.98 Å. The Mn(2)-O(4) bond length is 2.12 Å. There is one shorter (1.92 Å) and one longer (2.20 Å) Mn(2)-O(1) bond length. There is one shorter (2.02 Å) and one longer (2.33 Å) Mn(2)-O(2) bond length. Cd(1) is bonded to one O(1), one O(4), and two equivalent O(3) atoms to form distorted CdO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with three equivalent Mn(1)O6 octahedra, corners with five equivalent Mn(2)O6 octahedra, and  an edgeedge with one Cd(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-87°. The Cd(1)-O(1) bond length is 2.17 Å. The Cd(1)-O(4) bond length is 2.20 Å. There is one shorter (2.20 Å) and one longer (2.34 Å) Cd(1)-O(3) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), two equivalent Mn(2), and one Cd(1) atom to form distorted OMgMn2Cd tetrahedra that share  a cornercorner with one O(1)MgMn2Cd tetrahedra, corners with four equivalent O(2)MgMn3 trigonal pyramids, corners with four equivalent O(3)Mn2Cd2 trigonal pyramids,  an edgeedge with one O(1)MgMn2Cd tetrahedra, and  an edgeedge with one O(2)MgMn3 trigonal pyramid. In the second O site, O(2) is bonded to one Mg(1), one Mn(1), and two equivalent Mn(2) atoms to form distorted OMgMn3 trigonal pyramids that share corners with four equivalent O(1)MgMn2Cd tetrahedra, corners with two equivalent O(2)MgMn3 trigonal pyramids, corners with two equivalent O(3)Mn2Cd2 trigonal pyramids,  an edgeedge with one O(1)MgMn2Cd tetrahedra,  an edgeedge with one O(2)MgMn3 trigonal pyramid, and  an edgeedge with one O(3)Mn2Cd2 trigonal pyramid. In the third O site, O(3) is bonded to one Mn(1), one Mn(2), and two equivalent Cd(1) atoms to form distorted OMn2Cd2 trigonal pyramids that share corners with four equivalent O(1)MgMn2Cd tetrahedra,  a cornercorner with one O(3)Mn2Cd2 trigonal pyramid, corners with two equivalent O(2)MgMn3 trigonal pyramids,  an edgeedge with one O(2)MgMn3 trigonal pyramid, and  an edgeedge with one O(3)Mn2Cd2 trigonal pyramid. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Mg(1), one Mn(1), one Mn(2), and one Cd(1) atom.