MgMn4Zn2O8 crystallizes in the triclinic P-1 space group. Mg(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form MgO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra and edges with four equivalent Mn(2)O6 octahedra. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), and two equivalent O(3) atoms. In the second Mn site, Mn(2) is bonded to one O(1), two equivalent O(2), and three equivalent O(4) atoms to form distorted MnO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra and edges with four equivalent Mn(2)O6 octahedra. Zn(1) is bonded in a distorted see-saw-like geometry to one O(1), one O(4), and two equivalent O(3) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1), one Mn(1), one Mn(2), and one Zn(1) atom to form distorted OMg2Mn2Zn trigonal bipyramids that share corners with four equivalent O(1)Mg2Mn2Zn trigonal bipyramids,  a cornercorner with one O(2)MgMn3 trigonal pyramid, corners with two equivalent O(4)Mn3Zn trigonal pyramids,  an edgeedge with one O(1)Mg2Mn2Zn trigonal bipyramid,  an edgeedge with one O(4)Mn3Zn trigonal pyramid, and edges with three equivalent O(2)MgMn3 trigonal pyramids. In the second O site, O(2) is bonded to one Mg(1), one Mn(1), and two equivalent Mn(2) atoms to form OMgMn3 trigonal pyramids that share  a cornercorner with one O(1)Mg2Mn2Zn trigonal bipyramid, corners with three equivalent O(2)MgMn3 trigonal pyramids, corners with four equivalent O(4)Mn3Zn trigonal pyramids, edges with three equivalent O(1)Mg2Mn2Zn trigonal bipyramids, and  an edgeedge with one O(4)Mn3Zn trigonal pyramid. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mn(1) and two equivalent Zn(1) atoms. In the fourth O site, O(4) is bonded to three equivalent Mn(2) and one Zn(1) atom to form OMn3Zn trigonal pyramids that share corners with two equivalent O(1)Mg2Mn2Zn trigonal bipyramids, corners with two equivalent O(4)Mn3Zn trigonal pyramids, corners with four equivalent O(2)MgMn3 trigonal pyramids,  an edgeedge with one O(1)Mg2Mn2Zn trigonal bipyramid,  an edgeedge with one O(2)MgMn3 trigonal pyramid, and edges with two equivalent O(4)Mn3Zn trigonal pyramids.
MgMn4Zn2O8 crystallizes in the triclinic P-1 space group. Mg(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form MgO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra and edges with four equivalent Mn(2)O6 octahedra. Both Mg(1)-O(2) bond lengths are 2.18 Å. There are two shorter (2.06 Å) and two longer (2.10 Å) Mg(1)-O(1) bond lengths. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), and two equivalent O(3) atoms. The Mn(1)-O(1) bond length is 2.09 Å. The Mn(1)-O(2) bond length is 2.12 Å. Both Mn(1)-O(3) bond lengths are 2.10 Å. In the second Mn site, Mn(2) is bonded to one O(1), two equivalent O(2), and three equivalent O(4) atoms to form distorted MnO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra and edges with four equivalent Mn(2)O6 octahedra. The Mn(2)-O(1) bond length is 2.49 Å. There is one shorter (1.98 Å) and one longer (2.01 Å) Mn(2)-O(2) bond length. There are a spread of Mn(2)-O(4) bond distances ranging from 2.00-2.21 Å. Zn(1) is bonded in a distorted see-saw-like geometry to one O(1), one O(4), and two equivalent O(3) atoms. The Zn(1)-O(1) bond length is 2.04 Å. The Zn(1)-O(4) bond length is 1.99 Å. There is one shorter (2.00 Å) and one longer (2.06 Å) Zn(1)-O(3) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1), one Mn(1), one Mn(2), and one Zn(1) atom to form distorted OMg2Mn2Zn trigonal bipyramids that share corners with four equivalent O(1)Mg2Mn2Zn trigonal bipyramids,  a cornercorner with one O(2)MgMn3 trigonal pyramid, corners with two equivalent O(4)Mn3Zn trigonal pyramids,  an edgeedge with one O(1)Mg2Mn2Zn trigonal bipyramid,  an edgeedge with one O(4)Mn3Zn trigonal pyramid, and edges with three equivalent O(2)MgMn3 trigonal pyramids. In the second O site, O(2) is bonded to one Mg(1), one Mn(1), and two equivalent Mn(2) atoms to form OMgMn3 trigonal pyramids that share  a cornercorner with one O(1)Mg2Mn2Zn trigonal bipyramid, corners with three equivalent O(2)MgMn3 trigonal pyramids, corners with four equivalent O(4)Mn3Zn trigonal pyramids, edges with three equivalent O(1)Mg2Mn2Zn trigonal bipyramids, and  an edgeedge with one O(4)Mn3Zn trigonal pyramid. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mn(1) and two equivalent Zn(1) atoms. In the fourth O site, O(4) is bonded to three equivalent Mn(2) and one Zn(1) atom to form OMn3Zn trigonal pyramids that share corners with two equivalent O(1)Mg2Mn2Zn trigonal bipyramids, corners with two equivalent O(4)Mn3Zn trigonal pyramids, corners with four equivalent O(2)MgMn3 trigonal pyramids,  an edgeedge with one O(1)Mg2Mn2Zn trigonal bipyramid,  an edgeedge with one O(2)MgMn3 trigonal pyramid, and edges with two equivalent O(4)Mn3Zn trigonal pyramids.