Mn3O4 crystallizes in the orthorhombic Pmc2_1 space group. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(5) atoms. In the second Mn site, Mn(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(4) atoms. In the third Mn site, Mn(3) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(4) atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 9-53°. In the fourth Mn site, Mn(4) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(5) atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 9-53°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Mn(1), one Mn(2), two equivalent Mn(3), and two equivalent Mn(4) atoms. In the second O site, O(2) is bonded to two equivalent Mn(1) and two equivalent Mn(4) atoms to form distorted OMn4 tetrahedra that share corners with two equivalent O(2)Mn4 tetrahedra, corners with two equivalent O(4)Mn5 trigonal bipyramids, corners with eight equivalent O(5)Mn5 trigonal bipyramids, and edges with two equivalent O(5)Mn5 trigonal bipyramids. In the third O site, O(3) is bonded to two equivalent Mn(2) and two equivalent Mn(3) atoms to form distorted OMn4 tetrahedra that share corners with two equivalent O(3)Mn4 tetrahedra, corners with two equivalent O(5)Mn5 trigonal bipyramids, corners with eight equivalent O(4)Mn5 trigonal bipyramids, and edges with two equivalent O(4)Mn5 trigonal bipyramids. In the fourth O site, O(4) is bonded to one Mn(4), two equivalent Mn(2), and two equivalent Mn(3) atoms to form distorted OMn5 trigonal bipyramids that share  a cornercorner with one O(2)Mn4 tetrahedra, corners with four equivalent O(3)Mn4 tetrahedra, corners with two equivalent O(4)Mn5 trigonal bipyramids,  an edgeedge with one O(3)Mn4 tetrahedra, edges with two equivalent O(5)Mn5 trigonal bipyramids, and edges with three equivalent O(4)Mn5 trigonal bipyramids. In the fifth O site, O(5) is bonded to one Mn(3), two equivalent Mn(1), and two equivalent Mn(4) atoms to form distorted OMn5 trigonal bipyramids that share  a cornercorner with one O(3)Mn4 tetrahedra, corners with four equivalent O(2)Mn4 tetrahedra, corners with two equivalent O(5)Mn5 trigonal bipyramids,  an edgeedge with one O(2)Mn4 tetrahedra, edges with two equivalent O(4)Mn5 trigonal bipyramids, and edges with three equivalent O(5)Mn5 trigonal bipyramids.
Mn3O4 crystallizes in the orthorhombic Pmc2_1 space group. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(5) atoms. Both Mn(1)-O(1) bond lengths are 2.68 Å. Both Mn(1)-O(2) bond lengths are 2.18 Å. There are two shorter (2.33 Å) and two longer (2.34 Å) Mn(1)-O(5) bond lengths. In the second Mn site, Mn(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(4) atoms. Both Mn(2)-O(1) bond lengths are 2.64 Å. There is one shorter (2.16 Å) and one longer (2.18 Å) Mn(2)-O(3) bond length. There are two shorter (2.30 Å) and two longer (2.40 Å) Mn(2)-O(4) bond lengths. In the third Mn site, Mn(3) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(4) atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 9-53°. The Mn(3)-O(3) bond length is 1.96 Å. The Mn(3)-O(5) bond length is 1.97 Å. There is one shorter (1.98 Å) and one longer (2.34 Å) Mn(3)-O(1) bond length. There is one shorter (1.98 Å) and one longer (2.33 Å) Mn(3)-O(4) bond length. In the fourth Mn site, Mn(4) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(5) atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 9-53°. The Mn(4)-O(2) bond length is 1.95 Å. The Mn(4)-O(4) bond length is 1.97 Å. There is one shorter (1.98 Å) and one longer (2.36 Å) Mn(4)-O(1) bond length. There is one shorter (1.97 Å) and one longer (2.32 Å) Mn(4)-O(5) bond length. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Mn(1), one Mn(2), two equivalent Mn(3), and two equivalent Mn(4) atoms. In the second O site, O(2) is bonded to two equivalent Mn(1) and two equivalent Mn(4) atoms to form distorted OMn4 tetrahedra that share corners with two equivalent O(2)Mn4 tetrahedra, corners with two equivalent O(4)Mn5 trigonal bipyramids, corners with eight equivalent O(5)Mn5 trigonal bipyramids, and edges with two equivalent O(5)Mn5 trigonal bipyramids. In the third O site, O(3) is bonded to two equivalent Mn(2) and two equivalent Mn(3) atoms to form distorted OMn4 tetrahedra that share corners with two equivalent O(3)Mn4 tetrahedra, corners with two equivalent O(5)Mn5 trigonal bipyramids, corners with eight equivalent O(4)Mn5 trigonal bipyramids, and edges with two equivalent O(4)Mn5 trigonal bipyramids. In the fourth O site, O(4) is bonded to one Mn(4), two equivalent Mn(2), and two equivalent Mn(3) atoms to form distorted OMn5 trigonal bipyramids that share  a cornercorner with one O(2)Mn4 tetrahedra, corners with four equivalent O(3)Mn4 tetrahedra, corners with two equivalent O(4)Mn5 trigonal bipyramids,  an edgeedge with one O(3)Mn4 tetrahedra, edges with two equivalent O(5)Mn5 trigonal bipyramids, and edges with three equivalent O(4)Mn5 trigonal bipyramids. In the fifth O site, O(5) is bonded to one Mn(3), two equivalent Mn(1), and two equivalent Mn(4) atoms to form distorted OMn5 trigonal bipyramids that share  a cornercorner with one O(3)Mn4 tetrahedra, corners with four equivalent O(2)Mn4 tetrahedra, corners with two equivalent O(5)Mn5 trigonal bipyramids,  an edgeedge with one O(2)Mn4 tetrahedra, edges with two equivalent O(4)Mn5 trigonal bipyramids, and edges with three equivalent O(5)Mn5 trigonal bipyramids.