Mg2Mn3O8 is beta indium sulfide-derived structured and crystallizes in the monoclinic C2/m space group. Mg(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), and four equivalent O(2) atoms. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form edge-sharing MnO6 octahedra. In the second Mn site, Mn(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form edge-sharing MnO6 octahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Mn(1), and two equivalent Mn(2) atoms. In the second O site, O(2) is bonded to two equivalent Mg(1), one Mn(1), and one Mn(2) atom to form a mixture of distorted edge and corner-sharing OMg2Mn2 tetrahedra. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mg(1) and two equivalent Mn(2) atoms.
Mg2Mn3O8 is beta indium sulfide-derived structured and crystallizes in the monoclinic C2/m space group. Mg(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), and four equivalent O(2) atoms. The Mg(1)-O(1) bond length is 2.24 Å. The Mg(1)-O(3) bond length is 2.06 Å. There are two shorter (2.06 Å) and two longer (2.19 Å) Mg(1)-O(2) bond lengths. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form edge-sharing MnO6 octahedra. Both Mn(1)-O(1) bond lengths are 1.90 Å. All Mn(1)-O(2) bond lengths are 1.89 Å. In the second Mn site, Mn(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form edge-sharing MnO6 octahedra. Both Mn(2)-O(1) bond lengths are 1.96 Å. Both Mn(2)-O(2) bond lengths are 1.89 Å. Both Mn(2)-O(3) bond lengths are 1.84 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Mn(1), and two equivalent Mn(2) atoms. In the second O site, O(2) is bonded to two equivalent Mg(1), one Mn(1), and one Mn(2) atom to form a mixture of distorted edge and corner-sharing OMg2Mn2 tetrahedra. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mg(1) and two equivalent Mn(2) atoms.