MgMn2O4 crystallizes in the monoclinic P2_1 space group. Mg(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form a mixture of corner and edge-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 12-60°. In the second Mn site, Mn(2) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form a mixture of corner and edge-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 12-60°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Mg(1), one Mn(1), and two equivalent Mn(2) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Mg(1), one Mn(2), and two equivalent Mn(1) atoms. In the third O site, O(3) is bonded to two equivalent Mg(1), one Mn(1), and one Mn(2) atom to form OMg2Mn2 tetrahedra that share corners with two equivalent O(3)Mg2Mn2 tetrahedra and edges with four equivalent O(4)Mg2Mn4 octahedra. In the fourth O site, O(4) is bonded to two equivalent Mg(1), two equivalent Mn(1), and two equivalent Mn(2) atoms to form distorted OMg2Mn4 octahedra that share corners with two equivalent O(4)Mg2Mn4 octahedra, edges with two equivalent O(4)Mg2Mn4 octahedra, and edges with four equivalent O(3)Mg2Mn2 tetrahedra. The corner-sharing octahedral tilt angles are 44°.
MgMn2O4 crystallizes in the monoclinic P2_1 space group. Mg(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms. The Mg(1)-O(1) bond length is 2.09 Å. The Mg(1)-O(2) bond length is 2.09 Å. Both Mg(1)-O(3) bond lengths are 2.05 Å. There is one shorter (2.50 Å) and one longer (2.53 Å) Mg(1)-O(4) bond length. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms to form a mixture of corner and edge-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 12-60°. The Mn(1)-O(1) bond length is 1.97 Å. The Mn(1)-O(3) bond length is 1.97 Å. There is one shorter (1.95 Å) and one longer (2.31 Å) Mn(1)-O(2) bond length. There is one shorter (1.97 Å) and one longer (2.41 Å) Mn(1)-O(4) bond length. In the second Mn site, Mn(2) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form a mixture of corner and edge-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles range from 12-60°. The Mn(2)-O(2) bond length is 1.97 Å. The Mn(2)-O(3) bond length is 1.97 Å. There is one shorter (1.95 Å) and one longer (2.31 Å) Mn(2)-O(1) bond length. There is one shorter (1.97 Å) and one longer (2.42 Å) Mn(2)-O(4) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Mg(1), one Mn(1), and two equivalent Mn(2) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Mg(1), one Mn(2), and two equivalent Mn(1) atoms. In the third O site, O(3) is bonded to two equivalent Mg(1), one Mn(1), and one Mn(2) atom to form OMg2Mn2 tetrahedra that share corners with two equivalent O(3)Mg2Mn2 tetrahedra and edges with four equivalent O(4)Mg2Mn4 octahedra. In the fourth O site, O(4) is bonded to two equivalent Mg(1), two equivalent Mn(1), and two equivalent Mn(2) atoms to form distorted OMg2Mn4 octahedra that share corners with two equivalent O(4)Mg2Mn4 octahedra, edges with two equivalent O(4)Mg2Mn4 octahedra, and edges with four equivalent O(3)Mg2Mn2 tetrahedra. The corner-sharing octahedral tilt angles are 44°.