Ti2AlO4 crystallizes in the orthorhombic Imma space group. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form TiO6 octahedra that share edges with two equivalent Ti(1)O6 octahedra, edges with four equivalent Ti(2)O6 octahedra, and edges with four equivalent Al(1)O6 octahedra. In the second Ti site, Ti(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form TiO6 octahedra that share corners with six equivalent Al(1)O6 octahedra, edges with two equivalent Ti(2)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, and edges with four equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-7°. Al(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form AlO6 octahedra that share corners with six equivalent Ti(2)O6 octahedra, edges with two equivalent Ti(2)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, and edges with four equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-7°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Ti(2), two equivalent Ti(1), and one Al(1) atom. In the second O site, O(2) is bonded to one Ti(1), two equivalent Ti(2), and two equivalent Al(1) atoms to form a mixture of corner and edge-sharing OTi3Al2 square pyramids.
Ti2AlO4 crystallizes in the orthorhombic Imma space group. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form TiO6 octahedra that share edges with two equivalent Ti(1)O6 octahedra, edges with four equivalent Ti(2)O6 octahedra, and edges with four equivalent Al(1)O6 octahedra. Both Ti(1)-O(2) bond lengths are 2.06 Å. All Ti(1)-O(1) bond lengths are 2.03 Å. In the second Ti site, Ti(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form TiO6 octahedra that share corners with six equivalent Al(1)O6 octahedra, edges with two equivalent Ti(2)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, and edges with four equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-7°. Both Ti(2)-O(1) bond lengths are 2.16 Å. All Ti(2)-O(2) bond lengths are 2.22 Å. Al(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form AlO6 octahedra that share corners with six equivalent Ti(2)O6 octahedra, edges with two equivalent Ti(2)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, and edges with four equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-7°. Both Al(1)-O(1) bond lengths are 1.91 Å. All Al(1)-O(2) bond lengths are 1.94 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 Ti(2), two equivalent Ti(1), and one Al(1) atom. In the second O site, O(2) is bonded to one Ti(1), two equivalent Ti(2), and two equivalent Al(1) atoms to form a mixture of corner and edge-sharing OTi3Al2 square pyramids.