MgMn2O4 crystallizes in the monoclinic P2/m space group. Mg(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form MgO6 octahedra that share corners with four equivalent Mn(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and faces with two equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles are 35°. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted MnO6 octahedra that share corners with four equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, and faces with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles are 35°. In the second Mn site, Mn(2) is bonded in a distorted square co-planar geometry to two equivalent O(1) and four equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Mg(1), one Mn(2), and two equivalent Mn(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Mg(1), one Mn(1), and two equivalent Mn(2) atoms.
MgMn2O4 crystallizes in the monoclinic P2/m space group. Mg(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form MgO6 octahedra that share corners with four equivalent Mn(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and faces with two equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles are 35°. Both Mg(1)-O(2) bond lengths are 2.01 Å. All Mg(1)-O(1) bond lengths are 2.14 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted MnO6 octahedra that share corners with four equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, and faces with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles are 35°. Both Mn(1)-O(2) bond lengths are 2.46 Å. All Mn(1)-O(1) bond lengths are 1.97 Å. In the second Mn site, Mn(2) is bonded in a distorted square co-planar geometry to two equivalent O(1) and four equivalent O(2) atoms. Both Mn(2)-O(1) bond lengths are 2.73 Å. All Mn(2)-O(2) bond lengths are 1.93 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Mg(1), one Mn(2), and two equivalent Mn(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Mg(1), one Mn(1), and two equivalent Mn(2) atoms.