ZnMn2O4 crystallizes in the orthorhombic Cmcm space group. Mn(1) is bonded to one O(2), two equivalent O(3), and three equivalent O(1) atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 0-55°. Zn(1) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(1) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Mn(1) and two equivalent Zn(1) atoms to form distorted OMn3Zn2 trigonal bipyramids that share corners with five equivalent O(2)Mn2Zn2 tetrahedra, corners with two equivalent O(1)Mn3Zn2 trigonal bipyramids,  an edgeedge with one O(2)Mn2Zn2 tetrahedra, and edges with five equivalent O(1)Mn3Zn2 trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Mn(1) and two equivalent Zn(1) atoms to form OMn2Zn2 tetrahedra that share corners with two equivalent O(2)Mn2Zn2 tetrahedra, corners with ten equivalent O(1)Mn3Zn2 trigonal bipyramids, and edges with two equivalent O(1)Mn3Zn2 trigonal bipyramids. In the third O site, O(3) is bonded in a square co-planar geometry to four equivalent Mn(1) atoms.
ZnMn2O4 crystallizes in the orthorhombic Cmcm space group. Mn(1) is bonded to one O(2), two equivalent O(3), and three equivalent O(1) atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 0-55°. The Mn(1)-O(2) bond length is 1.97 Å. Both Mn(1)-O(3) bond lengths are 2.10 Å. There is one shorter (1.99 Å) and two longer (2.12 Å) Mn(1)-O(1) bond lengths. Zn(1) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(1) atoms. Both Zn(1)-O(2) bond lengths are 2.11 Å. All Zn(1)-O(1) bond lengths are 2.30 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Mn(1) and two equivalent Zn(1) atoms to form distorted OMn3Zn2 trigonal bipyramids that share corners with five equivalent O(2)Mn2Zn2 tetrahedra, corners with two equivalent O(1)Mn3Zn2 trigonal bipyramids,  an edgeedge with one O(2)Mn2Zn2 tetrahedra, and edges with five equivalent O(1)Mn3Zn2 trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Mn(1) and two equivalent Zn(1) atoms to form OMn2Zn2 tetrahedra that share corners with two equivalent O(2)Mn2Zn2 tetrahedra, corners with ten equivalent O(1)Mn3Zn2 trigonal bipyramids, and edges with two equivalent O(1)Mn3Zn2 trigonal bipyramids. In the third O site, O(3) is bonded in a square co-planar geometry to four equivalent Mn(1) atoms.