GaAlO3 crystallizes in the orthorhombic Pna2_1 space group. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted GaO6 octahedra that share corners with four equivalent Al(1)O4 tetrahedra and edges with three equivalent Al(2)O6 octahedra. In the second Ga site, Ga(2) is bonded in a 6-coordinate geometry to one O(2), one O(6), two equivalent O(3), and two equivalent O(4) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(2), one O(5), and two equivalent O(1) atoms to form AlO4 tetrahedra that share corners with three equivalent Al(2)O6 octahedra, corners with four equivalent Ga(1)O6 octahedra, and corners with two equivalent Al(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-68°. In the second Al site, Al(2) is bonded to one O(2), one O(6), two equivalent O(3), and two equivalent O(5) atoms to form AlO6 octahedra that share corners with three equivalent Al(1)O4 tetrahedra, edges with two equivalent Al(2)O6 octahedra, and edges with three equivalent Ga(1)O6 octahedra. There are six inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Ga(1) and two equivalent Al(1) atoms. In the second O site, O(2) is bonded to one Ga(1), one Ga(2), one Al(1), and one Al(2) atom to form OAl2Ga2 tetrahedra that share  a cornercorner with one O(3)Al2Ga3 square pyramid, corners with two equivalent O(5)Al3Ga tetrahedra, edges with two equivalent O(3)Al2Ga3 square pyramids, and  an edgeedge with one O(5)Al3Ga tetrahedra. In the third O site, O(3) is bonded to one Ga(1), two equivalent Ga(2), and two equivalent Al(2) atoms to form distorted OAl2Ga3 square pyramids that share  a cornercorner with one O(2)Al2Ga2 tetrahedra,  a cornercorner with one O(5)Al3Ga tetrahedra, edges with two equivalent O(3)Al2Ga3 square pyramids, edges with two equivalent O(2)Al2Ga2 tetrahedra, and edges with two equivalent O(5)Al3Ga tetrahedra. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Ga(1) and two equivalent Ga(2) atoms. In the fifth O site, O(5) is bonded to one Ga(1), one Al(1), and two equivalent Al(2) atoms to form distorted OAl3Ga tetrahedra that share  a cornercorner with one O(3)Al2Ga3 square pyramid, corners with two equivalent O(2)Al2Ga2 tetrahedra, corners with two equivalent O(5)Al3Ga tetrahedra, edges with two equivalent O(3)Al2Ga3 square pyramids, and  an edgeedge with one O(2)Al2Ga2 tetrahedra. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Ga(1), one Ga(2), and one Al(2) atom.
GaAlO3 crystallizes in the orthorhombic Pna2_1 space group. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted GaO6 octahedra that share corners with four equivalent Al(1)O4 tetrahedra and edges with three equivalent Al(2)O6 octahedra. The Ga(1)-O(1) bond length is 1.98 Å. The Ga(1)-O(2) bond length is 2.05 Å. The Ga(1)-O(3) bond length is 2.24 Å. The Ga(1)-O(4) bond length is 1.89 Å. The Ga(1)-O(5) bond length is 2.15 Å. The Ga(1)-O(6) bond length is 1.91 Å. In the second Ga site, Ga(2) is bonded in a 6-coordinate geometry to one O(2), one O(6), two equivalent O(3), and two equivalent O(4) atoms. The Ga(2)-O(2) bond length is 2.06 Å. The Ga(2)-O(6) bond length is 1.89 Å. There is one shorter (2.13 Å) and one longer (2.38 Å) Ga(2)-O(3) bond length. There is one shorter (1.91 Å) and one longer (1.92 Å) Ga(2)-O(4) bond length. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(2), one O(5), and two equivalent O(1) atoms to form AlO4 tetrahedra that share corners with three equivalent Al(2)O6 octahedra, corners with four equivalent Ga(1)O6 octahedra, and corners with two equivalent Al(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-68°. The Al(1)-O(2) bond length is 1.80 Å. The Al(1)-O(5) bond length is 1.80 Å. There is one shorter (1.77 Å) and one longer (1.78 Å) Al(1)-O(1) bond length. In the second Al site, Al(2) is bonded to one O(2), one O(6), two equivalent O(3), and two equivalent O(5) atoms to form AlO6 octahedra that share corners with three equivalent Al(1)O4 tetrahedra, edges with two equivalent Al(2)O6 octahedra, and edges with three equivalent Ga(1)O6 octahedra. The Al(2)-O(2) bond length is 2.00 Å. The Al(2)-O(6) bond length is 1.83 Å. There is one shorter (1.91 Å) and one longer (2.00 Å) Al(2)-O(3) bond length. There is one shorter (1.94 Å) and one longer (1.99 Å) Al(2)-O(5) bond length. There are six inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Ga(1) and two equivalent Al(1) atoms. In the second O site, O(2) is bonded to one Ga(1), one Ga(2), one Al(1), and one Al(2) atom to form OAl2Ga2 tetrahedra that share  a cornercorner with one O(3)Al2Ga3 square pyramid, corners with two equivalent O(5)Al3Ga tetrahedra, edges with two equivalent O(3)Al2Ga3 square pyramids, and  an edgeedge with one O(5)Al3Ga tetrahedra. In the third O site, O(3) is bonded to one Ga(1), two equivalent Ga(2), and two equivalent Al(2) atoms to form distorted OAl2Ga3 square pyramids that share  a cornercorner with one O(2)Al2Ga2 tetrahedra,  a cornercorner with one O(5)Al3Ga tetrahedra, edges with two equivalent O(3)Al2Ga3 square pyramids, edges with two equivalent O(2)Al2Ga2 tetrahedra, and edges with two equivalent O(5)Al3Ga tetrahedra. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Ga(1) and two equivalent Ga(2) atoms. In the fifth O site, O(5) is bonded to one Ga(1), one Al(1), and two equivalent Al(2) atoms to form distorted OAl3Ga tetrahedra that share  a cornercorner with one O(3)Al2Ga3 square pyramid, corners with two equivalent O(2)Al2Ga2 tetrahedra, corners with two equivalent O(5)Al3Ga tetrahedra, edges with two equivalent O(3)Al2Ga3 square pyramids, and  an edgeedge with one O(2)Al2Ga2 tetrahedra. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Ga(1), one Ga(2), and one Al(2) atom.