MgMn4Cd2O8 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(8) atom to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Mn(4)O6 octahedra, corners with five equivalent Mn(3)O6 octahedra,  an edgeedge with one Mn(1)O6 octahedra,  an edgeedge with one Mn(4)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Cd(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 8-74°. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form distorted MnO6 octahedra that share  a cornercorner with one Mg(1)O5 trigonal bipyramid,  a cornercorner with one Cd(1)O5 trigonal bipyramid, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, edges with two equivalent Mn(4)O6 octahedra,  an edgeedge with one Mg(1)O5 trigonal bipyramid, and  an edgeedge with one Cd(1)O5 trigonal bipyramid. In the second Mn site, Mn(2) 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 five equivalent Cd(1)O5 trigonal bipyramids, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, edges with two equivalent Mn(4)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. In the third Mn site, Mn(3) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(8) atom to form MnO6 octahedra that share corners with five equivalent Mg(1)O5 trigonal bipyramids, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(4)O6 octahedra, and edges with two equivalent Cd(1)O5 trigonal bipyramids. In the fourth Mn site, Mn(4) 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 distorted MnO6 octahedra that share  a cornercorner with one Mg(1)O5 trigonal bipyramid,  a cornercorner with one Cd(1)O5 trigonal bipyramid, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra,  an edgeedge with one Mg(1)O5 trigonal bipyramid, and  an edgeedge with one Cd(1)O5 trigonal bipyramid. There are two inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to one O(1), one O(3), one O(4), one O(7), and one O(8) atom to form distorted CdO5 trigonal bipyramids that share  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Mn(4)O6 octahedra, corners with five equivalent Mn(2)O6 octahedra,  an edgeedge with one Mn(1)O6 octahedra,  an edgeedge with one Mn(4)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 15-72°. In the second Cd site, Cd(2) is bonded in a 4-coordinate geometry to one O(1), one O(3), one O(5), and one O(6) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Mn(1), one Mn(2), one Mn(3), one Cd(1), and one Cd(2) atom to form distorted OMgMn3Cd2 octahedra that share  a cornercorner with one O(5)Mn3Cd tetrahedra,  a cornercorner with one O(6)Mn3Cd tetrahedra, corners with five equivalent O(4)MgMn3Cd trigonal bipyramids,  a cornercorner with one O(7)Mn3Cd trigonal pyramid,  an edgeedge with one O(3)MgMn3Cd2 octahedra,  an edgeedge with one O(5)Mn3Cd tetrahedra,  an edgeedge with one O(6)Mn3Cd tetrahedra, edges with two equivalent O(8)MgMn3Cd trigonal bipyramids,  an edgeedge with one O(7)Mn3Cd trigonal pyramid, and  a faceface with one O(3)MgMn3Cd2 octahedra. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Mn(1), one Mn(3), and one Mn(4) atom. In the third O site, O(3) is bonded to one Mg(1), one Mn(2), one Mn(3), one Mn(4), one Cd(1), and one Cd(2) atom to form distorted OMgMn3Cd2 octahedra that share  a cornercorner with one O(5)Mn3Cd tetrahedra,  a cornercorner with one O(6)Mn3Cd tetrahedra, corners with five equivalent O(8)MgMn3Cd trigonal bipyramids,  a cornercorner with one O(7)Mn3Cd trigonal pyramid,  an edgeedge with one O(1)MgMn3Cd2 octahedra,  an edgeedge with one O(5)Mn3Cd tetrahedra,  an edgeedge with one O(6)Mn3Cd tetrahedra, edges with two equivalent O(4)MgMn3Cd trigonal bipyramids,  an edgeedge with one O(7)Mn3Cd trigonal pyramid, and  a faceface with one O(1)MgMn3Cd2 octahedra. In the fourth O site, O(4) is bonded to one Mg(1), one Mn(1), one Mn(2), one Mn(3), and one Cd(1) atom to form OMgMn3Cd trigonal bipyramids that share corners with five equivalent O(1)MgMn3Cd2 octahedra, corners with two equivalent O(5)Mn3Cd tetrahedra, corners with two equivalent O(6)Mn3Cd tetrahedra,  a cornercorner with one O(7)Mn3Cd trigonal pyramid, edges with two equivalent O(3)MgMn3Cd2 octahedra, edges with two equivalent O(8)MgMn3Cd trigonal bipyramids, and  an edgeedge with one O(7)Mn3Cd trigonal pyramid. The corner-sharing octahedral tilt angles range from 2-33°. In the fifth O site, O(5) is bonded to one Mn(1), one Mn(3), one Mn(4), and one Cd(2) atom to form OMn3Cd tetrahedra that share  a cornercorner with one O(1)MgMn3Cd2 octahedra,  a cornercorner with one O(3)MgMn3Cd2 octahedra,  a cornercorner with one O(6)Mn3Cd tetrahedra, corners with two equivalent O(4)MgMn3Cd trigonal bipyramids, corners with two equivalent O(8)MgMn3Cd trigonal bipyramids, corners with two equivalent O(7)Mn3Cd trigonal pyramids,  an edgeedge with one O(1)MgMn3Cd2 octahedra,  an edgeedge with one O(3)MgMn3Cd2 octahedra, and  an edgeedge with one O(6)Mn3Cd tetrahedra. The corner-sharing octahedral tilt angles are 74°. In the sixth O site, O(6) is bonded to one Mn(1), one Mn(2), one Mn(4), and one Cd(2) atom to form OMn3Cd tetrahedra that share  a cornercorner with one O(1)MgMn3Cd2 octahedra,  a cornercorner with one O(3)MgMn3Cd2 octahedra,  a cornercorner with one O(5)Mn3Cd tetrahedra, corners with two equivalent O(4)MgMn3Cd trigonal bipyramids, corners with two equivalent O(8)MgMn3Cd trigonal bipyramids, corners with three equivalent O(7)Mn3Cd trigonal pyramids,  an edgeedge with one O(1)MgMn3Cd2 octahedra,  an edgeedge with one O(3)MgMn3Cd2 octahedra, and  an edgeedge with one O(5)Mn3Cd tetrahedra. The corner-sharing octahedral tilt angles range from 67-68°. In the seventh O site, O(7) is bonded to one Mn(1), one Mn(2), one Mn(4), and one Cd(1) atom to form distorted OMn3Cd trigonal pyramids that share  a cornercorner with one O(1)MgMn3Cd2 octahedra,  a cornercorner with one O(3)MgMn3Cd2 octahedra, corners with two equivalent O(5)Mn3Cd tetrahedra, corners with three equivalent O(6)Mn3Cd tetrahedra,  a cornercorner with one O(4)MgMn3Cd trigonal bipyramid,  a cornercorner with one O(8)MgMn3Cd trigonal bipyramid,  an edgeedge with one O(1)MgMn3Cd2 octahedra,  an edgeedge with one O(3)MgMn3Cd2 octahedra,  an edgeedge with one O(4)MgMn3Cd trigonal bipyramid, and  an edgeedge with one O(8)MgMn3Cd trigonal bipyramid. The corner-sharing octahedral tilt angles are 84°. In the eighth O site, O(8) is bonded to one Mg(1), one Mn(2), one Mn(3), one Mn(4), and one Cd(1) atom to form OMgMn3Cd trigonal bipyramids that share corners with five equivalent O(3)MgMn3Cd2 octahedra, corners with two equivalent O(5)Mn3Cd tetrahedra, corners with two equivalent O(6)Mn3Cd tetrahedra,  a cornercorner with one O(7)Mn3Cd trigonal pyramid, edges with two equivalent O(1)MgMn3Cd2 octahedra, edges with two equivalent O(4)MgMn3Cd trigonal bipyramids, and  an edgeedge with one O(7)Mn3Cd trigonal pyramid. The corner-sharing octahedral tilt angles range from 2-33°.
MgMn4Cd2O8 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(8) atom to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Mn(4)O6 octahedra, corners with five equivalent Mn(3)O6 octahedra,  an edgeedge with one Mn(1)O6 octahedra,  an edgeedge with one Mn(4)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Cd(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 8-74°. The Mg(1)-O(1) bond length is 2.19 Å. The Mg(1)-O(2) bond length is 2.07 Å. The Mg(1)-O(3) bond length is 2.19 Å. The Mg(1)-O(4) bond length is 2.11 Å. The Mg(1)-O(8) bond length is 2.12 Å. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form distorted MnO6 octahedra that share  a cornercorner with one Mg(1)O5 trigonal bipyramid,  a cornercorner with one Cd(1)O5 trigonal bipyramid, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, edges with two equivalent Mn(4)O6 octahedra,  an edgeedge with one Mg(1)O5 trigonal bipyramid, and  an edgeedge with one Cd(1)O5 trigonal bipyramid. The Mn(1)-O(1) bond length is 2.56 Å. The Mn(1)-O(2) bond length is 1.99 Å. The Mn(1)-O(4) bond length is 2.23 Å. The Mn(1)-O(5) bond length is 2.00 Å. The Mn(1)-O(6) bond length is 1.97 Å. The Mn(1)-O(7) bond length is 1.97 Å. In the second Mn site, Mn(2) 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 five equivalent Cd(1)O5 trigonal bipyramids, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, edges with two equivalent Mn(4)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. The Mn(2)-O(1) bond length is 2.16 Å. The Mn(2)-O(3) bond length is 2.16 Å. The Mn(2)-O(4) bond length is 2.16 Å. The Mn(2)-O(6) bond length is 2.27 Å. The Mn(2)-O(7) bond length is 2.21 Å. The Mn(2)-O(8) bond length is 2.16 Å. In the third Mn site, Mn(3) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(8) atom to form MnO6 octahedra that share corners with five equivalent Mg(1)O5 trigonal bipyramids, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(4)O6 octahedra, and edges with two equivalent Cd(1)O5 trigonal bipyramids. The Mn(3)-O(1) bond length is 2.26 Å. The Mn(3)-O(2) bond length is 2.34 Å. The Mn(3)-O(3) bond length is 2.25 Å. The Mn(3)-O(4) bond length is 2.34 Å. The Mn(3)-O(5) bond length is 2.33 Å. The Mn(3)-O(8) bond length is 2.32 Å. In the fourth Mn site, Mn(4) 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 distorted MnO6 octahedra that share  a cornercorner with one Mg(1)O5 trigonal bipyramid,  a cornercorner with one Cd(1)O5 trigonal bipyramid, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra,  an edgeedge with one Mg(1)O5 trigonal bipyramid, and  an edgeedge with one Cd(1)O5 trigonal bipyramid. The Mn(4)-O(2) bond length is 2.00 Å. The Mn(4)-O(3) bond length is 2.55 Å. The Mn(4)-O(5) bond length is 2.01 Å. The Mn(4)-O(6) bond length is 1.97 Å. The Mn(4)-O(7) bond length is 1.97 Å. The Mn(4)-O(8) bond length is 2.23 Å. There are two inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to one O(1), one O(3), one O(4), one O(7), and one O(8) atom to form distorted CdO5 trigonal bipyramids that share  a cornercorner with one Mn(1)O6 octahedra,  a cornercorner with one Mn(4)O6 octahedra, corners with five equivalent Mn(2)O6 octahedra,  an edgeedge with one Mn(1)O6 octahedra,  an edgeedge with one Mn(4)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 15-72°. The Cd(1)-O(1) bond length is 2.41 Å. The Cd(1)-O(3) bond length is 2.42 Å. The Cd(1)-O(4) bond length is 2.23 Å. The Cd(1)-O(7) bond length is 2.20 Å. The Cd(1)-O(8) bond length is 2.23 Å. In the second Cd site, Cd(2) is bonded in a 4-coordinate geometry to one O(1), one O(3), one O(5), and one O(6) atom. The Cd(2)-O(1) bond length is 2.34 Å. The Cd(2)-O(3) bond length is 2.33 Å. The Cd(2)-O(5) bond length is 2.14 Å. The Cd(2)-O(6) bond length is 2.13 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Mn(1), one Mn(2), one Mn(3), one Cd(1), and one Cd(2) atom to form distorted OMgMn3Cd2 octahedra that share  a cornercorner with one O(5)Mn3Cd tetrahedra,  a cornercorner with one O(6)Mn3Cd tetrahedra, corners with five equivalent O(4)MgMn3Cd trigonal bipyramids,  a cornercorner with one O(7)Mn3Cd trigonal pyramid,  an edgeedge with one O(3)MgMn3Cd2 octahedra,  an edgeedge with one O(5)Mn3Cd tetrahedra,  an edgeedge with one O(6)Mn3Cd tetrahedra, edges with two equivalent O(8)MgMn3Cd trigonal bipyramids,  an edgeedge with one O(7)Mn3Cd trigonal pyramid, and  a faceface with one O(3)MgMn3Cd2 octahedra. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Mn(1), one Mn(3), and one Mn(4) atom. In the third O site, O(3) is bonded to one Mg(1), one Mn(2), one Mn(3), one Mn(4), one Cd(1), and one Cd(2) atom to form distorted OMgMn3Cd2 octahedra that share  a cornercorner with one O(5)Mn3Cd tetrahedra,  a cornercorner with one O(6)Mn3Cd tetrahedra, corners with five equivalent O(8)MgMn3Cd trigonal bipyramids,  a cornercorner with one O(7)Mn3Cd trigonal pyramid,  an edgeedge with one O(1)MgMn3Cd2 octahedra,  an edgeedge with one O(5)Mn3Cd tetrahedra,  an edgeedge with one O(6)Mn3Cd tetrahedra, edges with two equivalent O(4)MgMn3Cd trigonal bipyramids,  an edgeedge with one O(7)Mn3Cd trigonal pyramid, and  a faceface with one O(1)MgMn3Cd2 octahedra. In the fourth O site, O(4) is bonded to one Mg(1), one Mn(1), one Mn(2), one Mn(3), and one Cd(1) atom to form OMgMn3Cd trigonal bipyramids that share corners with five equivalent O(1)MgMn3Cd2 octahedra, corners with two equivalent O(5)Mn3Cd tetrahedra, corners with two equivalent O(6)Mn3Cd tetrahedra,  a cornercorner with one O(7)Mn3Cd trigonal pyramid, edges with two equivalent O(3)MgMn3Cd2 octahedra, edges with two equivalent O(8)MgMn3Cd trigonal bipyramids, and  an edgeedge with one O(7)Mn3Cd trigonal pyramid. The corner-sharing octahedral tilt angles range from 2-33°. In the fifth O site, O(5) is bonded to one Mn(1), one Mn(3), one Mn(4), and one Cd(2) atom to form OMn3Cd tetrahedra that share  a cornercorner with one O(1)MgMn3Cd2 octahedra,  a cornercorner with one O(3)MgMn3Cd2 octahedra,  a cornercorner with one O(6)Mn3Cd tetrahedra, corners with two equivalent O(4)MgMn3Cd trigonal bipyramids, corners with two equivalent O(8)MgMn3Cd trigonal bipyramids, corners with two equivalent O(7)Mn3Cd trigonal pyramids,  an edgeedge with one O(1)MgMn3Cd2 octahedra,  an edgeedge with one O(3)MgMn3Cd2 octahedra, and  an edgeedge with one O(6)Mn3Cd tetrahedra. The corner-sharing octahedral tilt angles are 74°. In the sixth O site, O(6) is bonded to one Mn(1), one Mn(2), one Mn(4), and one Cd(2) atom to form OMn3Cd tetrahedra that share  a cornercorner with one O(1)MgMn3Cd2 octahedra,  a cornercorner with one O(3)MgMn3Cd2 octahedra,  a cornercorner with one O(5)Mn3Cd tetrahedra, corners with two equivalent O(4)MgMn3Cd trigonal bipyramids, corners with two equivalent O(8)MgMn3Cd trigonal bipyramids, corners with three equivalent O(7)Mn3Cd trigonal pyramids,  an edgeedge with one O(1)MgMn3Cd2 octahedra,  an edgeedge with one O(3)MgMn3Cd2 octahedra, and  an edgeedge with one O(5)Mn3Cd tetrahedra. The corner-sharing octahedral tilt angles range from 67-68°. In the seventh O site, O(7) is bonded to one Mn(1), one Mn(2), one Mn(4), and one Cd(1) atom to form distorted OMn3Cd trigonal pyramids that share  a cornercorner with one O(1)MgMn3Cd2 octahedra,  a cornercorner with one O(3)MgMn3Cd2 octahedra, corners with two equivalent O(5)Mn3Cd tetrahedra, corners with three equivalent O(6)Mn3Cd tetrahedra,  a cornercorner with one O(4)MgMn3Cd trigonal bipyramid,  a cornercorner with one O(8)MgMn3Cd trigonal bipyramid,  an edgeedge with one O(1)MgMn3Cd2 octahedra,  an edgeedge with one O(3)MgMn3Cd2 octahedra,  an edgeedge with one O(4)MgMn3Cd trigonal bipyramid, and  an edgeedge with one O(8)MgMn3Cd trigonal bipyramid. The corner-sharing octahedral tilt angles are 84°. In the eighth O site, O(8) is bonded to one Mg(1), one Mn(2), one Mn(3), one Mn(4), and one Cd(1) atom to form OMgMn3Cd trigonal bipyramids that share corners with five equivalent O(3)MgMn3Cd2 octahedra, corners with two equivalent O(5)Mn3Cd tetrahedra, corners with two equivalent O(6)Mn3Cd tetrahedra,  a cornercorner with one O(7)Mn3Cd trigonal pyramid, edges with two equivalent O(1)MgMn3Cd2 octahedra, edges with two equivalent O(4)MgMn3Cd trigonal bipyramids, and  an edgeedge with one O(7)Mn3Cd trigonal pyramid. The corner-sharing octahedral tilt angles range from 2-33°.