MgMn2O4 is Corundum-derived structured and crystallizes in the orthorhombic Pmm2 space group. Mg(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted MgO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Mn(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with four equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-28°. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form MnO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, and edges with four equivalent Mn(2)O6 octahedra. The corner-sharing octahedra are not tilted. In the second Mn site, Mn(2) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted MnO6 octahedra that share corners with two equivalent Mn(2)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with four equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-26°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mn(1) and two equivalent Mn(2) atoms to form OMn4 trigonal pyramids that share corners with two equivalent O(2)Mg2Mn2 trigonal pyramids, corners with four equivalent O(1)Mn4 trigonal pyramids, edges with four equivalent O(4)Mg2Mn4 octahedra, and  an edgeedge with one O(2)Mg2Mn2 trigonal pyramid. In the second O site, O(2) is bonded to two equivalent Mg(1) and two equivalent Mn(1) atoms to form distorted OMg2Mn2 trigonal pyramids that share corners with two equivalent O(1)Mn4 trigonal pyramids, corners with four equivalent O(2)Mg2Mn2 trigonal pyramids, edges with four equivalent O(4)Mg2Mn4 octahedra, and  an edgeedge with one O(1)Mn4 trigonal pyramid. In the third O site, O(3) is bonded in a square co-planar geometry to two equivalent Mg(1) and two equivalent Mn(2) atoms. In the fourth O site, O(4) is bonded to two equivalent Mg(1), two equivalent Mn(1), and two equivalent Mn(2) atoms to form OMg2Mn4 octahedra that share corners with two equivalent O(4)Mg2Mn4 octahedra, edges with two equivalent O(4)Mg2Mn4 octahedra, edges with four equivalent O(2)Mg2Mn2 trigonal pyramids, and edges with four equivalent O(1)Mn4 trigonal pyramids. The corner-sharing octahedra are not tilted.
MgMn2O4 is Corundum-derived structured and crystallizes in the orthorhombic Pmm2 space group. Mg(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted MgO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Mn(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with four equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-28°. Both Mg(1)-O(2) bond lengths are 2.11 Å. Both Mg(1)-O(3) bond lengths are 2.04 Å. Both Mg(1)-O(4) bond lengths are 2.32 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form MnO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, and edges with four equivalent Mn(2)O6 octahedra. The corner-sharing octahedra are not tilted. Both Mn(1)-O(1) bond lengths are 2.01 Å. Both Mn(1)-O(2) bond lengths are 1.95 Å. Both Mn(1)-O(4) bond lengths are 2.04 Å. In the second Mn site, Mn(2) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted MnO6 octahedra that share corners with two equivalent Mn(2)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with four equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-26°. Both Mn(2)-O(1) bond lengths are 2.10 Å. Both Mn(2)-O(3) bond lengths are 2.06 Å. Both Mn(2)-O(4) bond lengths are 2.34 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mn(1) and two equivalent Mn(2) atoms to form OMn4 trigonal pyramids that share corners with two equivalent O(2)Mg2Mn2 trigonal pyramids, corners with four equivalent O(1)Mn4 trigonal pyramids, edges with four equivalent O(4)Mg2Mn4 octahedra, and  an edgeedge with one O(2)Mg2Mn2 trigonal pyramid. In the second O site, O(2) is bonded to two equivalent Mg(1) and two equivalent Mn(1) atoms to form distorted OMg2Mn2 trigonal pyramids that share corners with two equivalent O(1)Mn4 trigonal pyramids, corners with four equivalent O(2)Mg2Mn2 trigonal pyramids, edges with four equivalent O(4)Mg2Mn4 octahedra, and  an edgeedge with one O(1)Mn4 trigonal pyramid. In the third O site, O(3) is bonded in a square co-planar geometry to two equivalent Mg(1) and two equivalent Mn(2) atoms. In the fourth O site, O(4) is bonded to two equivalent Mg(1), two equivalent Mn(1), and two equivalent Mn(2) atoms to form OMg2Mn4 octahedra that share corners with two equivalent O(4)Mg2Mn4 octahedra, edges with two equivalent O(4)Mg2Mn4 octahedra, edges with four equivalent O(2)Mg2Mn2 trigonal pyramids, and edges with four equivalent O(1)Mn4 trigonal pyramids. The corner-sharing octahedra are not tilted.