Mn2AlO4 is Spinel structured and crystallizes in the trigonal R-3m space group. 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 MnO6 octahedra that share corners with six equivalent Al(1)O4 tetrahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with four equivalent Mn(1)O6 octahedra. In the second Mn site, Mn(2) is bonded to six equivalent O(1) atoms to form MnO6 octahedra that share corners with six equivalent Al(1)O4 tetrahedra and edges with six equivalent Mn(1)O6 octahedra. Al(1) is bonded to one O(2) and three equivalent O(1) atoms to form AlO4 tetrahedra that share corners with three equivalent Mn(2)O6 octahedra and corners with nine equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-57°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mn(2), two equivalent Mn(1), and one Al(1) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to three equivalent Mn(1) and one Al(1) atom.
Mn2AlO4 is Spinel structured and crystallizes in the trigonal R-3m space group. 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 MnO6 octahedra that share corners with six equivalent Al(1)O4 tetrahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with four equivalent Mn(1)O6 octahedra. Both Mn(1)-O(2) bond lengths are 2.19 Å. All Mn(1)-O(1) bond lengths are 2.08 Å. In the second Mn site, Mn(2) is bonded to six equivalent O(1) atoms to form MnO6 octahedra that share corners with six equivalent Al(1)O4 tetrahedra and edges with six equivalent Mn(1)O6 octahedra. All Mn(2)-O(1) bond lengths are 2.17 Å. Al(1) is bonded to one O(2) and three equivalent O(1) atoms to form AlO4 tetrahedra that share corners with three equivalent Mn(2)O6 octahedra and corners with nine equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-57°. The Al(1)-O(2) bond length is 1.79 Å. All Al(1)-O(1) bond lengths are 1.84 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mn(2), two equivalent Mn(1), and one Al(1) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to three equivalent Mn(1) and one Al(1) atom.