ZnMn2O4 crystallizes in the triclinic P-1 space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(2), two equivalent O(1), and two equivalent O(3) atoms to form MnO5 square pyramids that share corners with four equivalent Mn(2)O6 octahedra, corners with four equivalent Zn(1)O5 trigonal bipyramids, edges with two equivalent Mn(1)O5 square pyramids, and  an edgeedge with one Zn(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 49-52°. 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 corners with four equivalent Mn(1)O5 square pyramids, corners with four equivalent Zn(1)O5 trigonal bipyramids, edges with four equivalent Mn(2)O6 octahedra, and  a faceface with one Zn(1)O5 trigonal bipyramid. Zn(1) is bonded to one O(1), two equivalent O(3), and two equivalent O(4) atoms to form ZnO5 trigonal bipyramids that share corners with four equivalent Mn(2)O6 octahedra, corners with four equivalent Mn(1)O5 square pyramids,  an edgeedge with one Mn(1)O5 square pyramid, edges with two equivalent Zn(1)O5 trigonal bipyramids, and  a faceface with one Mn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-62°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mn(2), two equivalent Mn(1), and one Zn(1) atom to form distorted OMn3Zn tetrahedra that share corners with two equivalent O(1)Mn3Zn tetrahedra,  a cornercorner with one O(4)Mn3Zn2 trigonal bipyramid, and edges with two equivalent O(4)Mn3Zn2 trigonal bipyramids. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mn(1) and two equivalent Mn(2) atoms. In the third O site, O(3) is bonded in a square co-planar 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 two equivalent Zn(1) atoms to form distorted OMn3Zn2 trigonal bipyramids that share  a cornercorner with one O(1)Mn3Zn tetrahedra, edges with two equivalent O(1)Mn3Zn tetrahedra, and edges with four equivalent O(4)Mn3Zn2 trigonal bipyramids.
ZnMn2O4 crystallizes in the triclinic P-1 space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(2), two equivalent O(1), and two equivalent O(3) atoms to form MnO5 square pyramids that share corners with four equivalent Mn(2)O6 octahedra, corners with four equivalent Zn(1)O5 trigonal bipyramids, edges with two equivalent Mn(1)O5 square pyramids, and  an edgeedge with one Zn(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 49-52°. The Mn(1)-O(2) bond length is 2.07 Å. Both Mn(1)-O(1) bond lengths are 1.94 Å. There is one shorter (2.02 Å) and one longer (2.03 Å) Mn(1)-O(3) bond length. 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 corners with four equivalent Mn(1)O5 square pyramids, corners with four equivalent Zn(1)O5 trigonal bipyramids, edges with four equivalent Mn(2)O6 octahedra, and  a faceface with one Zn(1)O5 trigonal bipyramid. The Mn(2)-O(1) bond length is 2.33 Å. Both Mn(2)-O(2) bond lengths are 1.91 Å. There are two shorter (2.07 Å) and one longer (2.26 Å) Mn(2)-O(4) bond length. Zn(1) is bonded to one O(1), two equivalent O(3), and two equivalent O(4) atoms to form ZnO5 trigonal bipyramids that share corners with four equivalent Mn(2)O6 octahedra, corners with four equivalent Mn(1)O5 square pyramids,  an edgeedge with one Mn(1)O5 square pyramid, edges with two equivalent Zn(1)O5 trigonal bipyramids, and  a faceface with one Mn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-62°. The Zn(1)-O(1) bond length is 2.11 Å. There is one shorter (2.05 Å) and one longer (2.07 Å) Zn(1)-O(3) bond length. There is one shorter (2.09 Å) and one longer (2.14 Å) Zn(1)-O(4) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mn(2), two equivalent Mn(1), and one Zn(1) atom to form distorted OMn3Zn tetrahedra that share corners with two equivalent O(1)Mn3Zn tetrahedra,  a cornercorner with one O(4)Mn3Zn2 trigonal bipyramid, and edges with two equivalent O(4)Mn3Zn2 trigonal bipyramids. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mn(1) and two equivalent Mn(2) atoms. In the third O site, O(3) is bonded in a square co-planar 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 two equivalent Zn(1) atoms to form distorted OMn3Zn2 trigonal bipyramids that share  a cornercorner with one O(1)Mn3Zn tetrahedra, edges with two equivalent O(1)Mn3Zn tetrahedra, and edges with four equivalent O(4)Mn3Zn2 trigonal bipyramids.