Mg3MnO4 is Caswellsilverite-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form MgO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with four equivalent Mn(1)O6 octahedra, and edges with eight equivalent Mg(2)O6 octahedra. The corner-sharing octahedra are not tilted. In the second Mg site, Mg(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form MgO6 octahedra that share corners with six equivalent Mg(2)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(2)O6 octahedra, and edges with four equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. Mn(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form MnO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Mn(1)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, and edges with eight equivalent Mg(2)O6 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1), two equivalent Mg(2), and two equivalent Mn(1) atoms to form OMg4Mn2 octahedra that share corners with six equivalent O(1)Mg4Mn2 octahedra, edges with four equivalent O(1)Mg4Mn2 octahedra, and edges with eight equivalent O(2)Mg5Mn octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to one Mg(1), four equivalent Mg(2), and one Mn(1) atom to form OMg5Mn octahedra that share corners with six equivalent O(2)Mg5Mn octahedra, edges with four equivalent O(2)Mg5Mn octahedra, and edges with eight equivalent O(1)Mg4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 0-4°.
Mg3MnO4 is Caswellsilverite-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form MgO6 octahedra that share corners with two equivalent Mn(1)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with four equivalent Mn(1)O6 octahedra, and edges with eight equivalent Mg(2)O6 octahedra. The corner-sharing octahedra are not tilted. Both Mg(1)-O(2) bond lengths are 2.09 Å. All Mg(1)-O(1) bond lengths are 2.16 Å. In the second Mg site, Mg(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form MgO6 octahedra that share corners with six equivalent Mg(2)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(2)O6 octahedra, and edges with four equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-4°. Both Mg(2)-O(1) bond lengths are 2.17 Å. All Mg(2)-O(2) bond lengths are 2.16 Å. Mn(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form MnO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Mn(1)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, and edges with eight equivalent Mg(2)O6 octahedra. The corner-sharing octahedra are not tilted. Both Mn(1)-O(2) bond lengths are 2.24 Å. All Mn(1)-O(1) bond lengths are 2.16 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1), two equivalent Mg(2), and two equivalent Mn(1) atoms to form OMg4Mn2 octahedra that share corners with six equivalent O(1)Mg4Mn2 octahedra, edges with four equivalent O(1)Mg4Mn2 octahedra, and edges with eight equivalent O(2)Mg5Mn octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to one Mg(1), four equivalent Mg(2), and one Mn(1) atom to form OMg5Mn octahedra that share corners with six equivalent O(2)Mg5Mn octahedra, edges with four equivalent O(2)Mg5Mn octahedra, and edges with eight equivalent O(1)Mg4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 0-4°.