La5Ti4GaO17 crystallizes in the orthorhombic Pnnm space group. There are three inequivalent La sites. In the first La site, La(1) is bonded in a 7-coordinate geometry to one O(4), three equivalent O(1), and three equivalent O(7) atoms. In the second La site, La(2) is bonded to two equivalent O(3), two equivalent O(9), four equivalent O(2), and four equivalent O(6) atoms to form distorted LaO12 cuboctahedra that share corners with two equivalent La(2)O12 cuboctahedra, corners with eight equivalent La(3)O12 cuboctahedra, faces with two equivalent La(2)O12 cuboctahedra, faces with four equivalent La(3)O12 cuboctahedra, faces with four equivalent Ti(2)O6 octahedra, and faces with four equivalent Ga(1)O6 octahedra. In the third La site, La(3) is bonded to one O(4), one O(9), two equivalent O(2), two equivalent O(3), two equivalent O(5), two equivalent O(6), and two equivalent O(8) atoms to form distorted LaO12 cuboctahedra that share corners with three equivalent La(3)O12 cuboctahedra, corners with four equivalent La(2)O12 cuboctahedra, faces with two equivalent La(2)O12 cuboctahedra, faces with two equivalent La(3)O12 cuboctahedra, faces with two equivalent Ti(1)O6 octahedra, faces with two equivalent Ga(1)O6 octahedra, and faces with four equivalent Ti(2)O6 octahedra. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), one O(5), one O(7), one O(8), and two equivalent O(4) atoms to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra, and faces with two equivalent La(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 14-35°. In the second Ti site, Ti(2) is bonded to one O(2), one O(5), one O(6), one O(8), and two equivalent O(3) atoms to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra, corners with two equivalent Ga(1)O6 octahedra, faces with two equivalent La(2)O12 cuboctahedra, and faces with four equivalent La(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 14-35°. Ga(1) is bonded to two equivalent O(2), two equivalent O(6), and two equivalent O(9) atoms to form GaO6 octahedra that share corners with two equivalent Ga(1)O6 octahedra, corners with four equivalent Ti(2)O6 octahedra, faces with four equivalent La(2)O12 cuboctahedra, and faces with four equivalent La(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-20°. There are nine inequivalent O sites. In the first O site, O(4) is bonded in a 4-coordinate geometry to one La(1), one La(3), and two equivalent Ti(1) atoms. In the second O site, O(5) is bonded to two equivalent La(3), one Ti(1), and one Ti(2) atom to form distorted OLa2Ti2 tetrahedra that share corners with two equivalent O(9)La4Ga2 octahedra, corners with two equivalent O(3)La3Ti2 square pyramids,  a cornercorner with one O(7)La3Ti tetrahedra, corners with two equivalent O(5)La2Ti2 tetrahedra, and edges with two equivalent O(3)La3Ti2 square pyramids. The corner-sharing octahedral tilt angles are 66°. In the third O site, O(6) is bonded in a 4-coordinate geometry to two equivalent La(2), two equivalent La(3), one Ti(2), and one Ga(1) atom. In the fourth O site, O(7) is bonded to three equivalent La(1) and one Ti(1) atom to form OLa3Ti tetrahedra that share  a cornercorner with one O(5)La2Ti2 tetrahedra and corners with six equivalent O(7)La3Ti tetrahedra. In the fifth O site, O(8) is bonded in a 2-coordinate geometry to two equivalent La(3), one Ti(1), and one Ti(2) atom. In the sixth O site, O(1) is bonded in a 4-coordinate geometry to three equivalent La(1) and one Ti(1) atom. In the seventh O site, O(9) is bonded to two equivalent La(2), two equivalent La(3), and two equivalent Ga(1) atoms to form distorted OLa4Ga2 octahedra that share corners with four equivalent O(9)La4Ga2 octahedra, corners with four equivalent O(5)La2Ti2 tetrahedra, and edges with four equivalent O(3)La3Ti2 square pyramids. The corner-sharing octahedra are not tilted. In the eighth O site, O(2) is bonded in a 4-coordinate geometry to two equivalent La(2), two equivalent La(3), one Ti(2), and one Ga(1) atom. In the ninth O site, O(3) is bonded to one La(2), two equivalent La(3), and two equivalent Ti(2) atoms to form distorted OLa3Ti2 square pyramids that share corners with five equivalent O(3)La3Ti2 square pyramids, corners with two equivalent O(5)La2Ti2 tetrahedra, edges with two equivalent O(9)La4Ga2 octahedra, and edges with two equivalent O(5)La2Ti2 tetrahedra.
La5Ti4GaO17 crystallizes in the orthorhombic Pnnm space group. There are three inequivalent La sites. In the first La site, La(1) is bonded in a 7-coordinate geometry to one O(4), three equivalent O(1), and three equivalent O(7) atoms. The La(1)-O(4) bond length is 2.75 Å. There are two shorter (2.49 Å) and one longer (2.64 Å) La(1)-O(1) bond length. There are two shorter (2.41 Å) and one longer (2.44 Å) La(1)-O(7) bond length. In the second La site, La(2) is bonded to two equivalent O(3), two equivalent O(9), four equivalent O(2), and four equivalent O(6) atoms to form distorted LaO12 cuboctahedra that share corners with two equivalent La(2)O12 cuboctahedra, corners with eight equivalent La(3)O12 cuboctahedra, faces with two equivalent La(2)O12 cuboctahedra, faces with four equivalent La(3)O12 cuboctahedra, faces with four equivalent Ti(2)O6 octahedra, and faces with four equivalent Ga(1)O6 octahedra. Both La(2)-O(3) bond lengths are 2.65 Å. Both La(2)-O(9) bond lengths are 2.78 Å. All La(2)-O(2) bond lengths are 2.57 Å. All La(2)-O(6) bond lengths are 2.99 Å. In the third La site, La(3) is bonded to one O(4), one O(9), two equivalent O(2), two equivalent O(3), two equivalent O(5), two equivalent O(6), and two equivalent O(8) atoms to form distorted LaO12 cuboctahedra that share corners with three equivalent La(3)O12 cuboctahedra, corners with four equivalent La(2)O12 cuboctahedra, faces with two equivalent La(2)O12 cuboctahedra, faces with two equivalent La(3)O12 cuboctahedra, faces with two equivalent Ti(1)O6 octahedra, faces with two equivalent Ga(1)O6 octahedra, and faces with four equivalent Ti(2)O6 octahedra. The La(3)-O(4) bond length is 2.58 Å. The La(3)-O(9) bond length is 2.79 Å. Both La(3)-O(2) bond lengths are 3.05 Å. Both La(3)-O(3) bond lengths are 2.78 Å. Both La(3)-O(5) bond lengths are 2.48 Å. Both La(3)-O(6) bond lengths are 2.59 Å. Both La(3)-O(8) bond lengths are 2.92 Å. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), one O(5), one O(7), one O(8), and two equivalent O(4) atoms to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra, and faces with two equivalent La(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 14-35°. The Ti(1)-O(1) bond length is 1.84 Å. The Ti(1)-O(5) bond length is 1.99 Å. The Ti(1)-O(7) bond length is 1.91 Å. The Ti(1)-O(8) bond length is 2.18 Å. Both Ti(1)-O(4) bond lengths are 1.99 Å. In the second Ti site, Ti(2) is bonded to one O(2), one O(5), one O(6), one O(8), and two equivalent O(3) atoms to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra, corners with two equivalent Ga(1)O6 octahedra, faces with two equivalent La(2)O12 cuboctahedra, and faces with four equivalent La(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 14-35°. The Ti(2)-O(2) bond length is 2.11 Å. The Ti(2)-O(5) bond length is 1.94 Å. The Ti(2)-O(6) bond length is 2.00 Å. The Ti(2)-O(8) bond length is 1.83 Å. Both Ti(2)-O(3) bond lengths are 1.99 Å. Ga(1) is bonded to two equivalent O(2), two equivalent O(6), and two equivalent O(9) atoms to form GaO6 octahedra that share corners with two equivalent Ga(1)O6 octahedra, corners with four equivalent Ti(2)O6 octahedra, faces with four equivalent La(2)O12 cuboctahedra, and faces with four equivalent La(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-20°. Both Ga(1)-O(2) bond lengths are 1.97 Å. Both Ga(1)-O(6) bond lengths are 2.01 Å. Both Ga(1)-O(9) bond lengths are 1.98 Å. There are nine inequivalent O sites. In the first O site, O(4) is bonded in a 4-coordinate geometry to one La(1), one La(3), and two equivalent Ti(1) atoms. In the second O site, O(5) is bonded to two equivalent La(3), one Ti(1), and one Ti(2) atom to form distorted OLa2Ti2 tetrahedra that share corners with two equivalent O(9)La4Ga2 octahedra, corners with two equivalent O(3)La3Ti2 square pyramids,  a cornercorner with one O(7)La3Ti tetrahedra, corners with two equivalent O(5)La2Ti2 tetrahedra, and edges with two equivalent O(3)La3Ti2 square pyramids. The corner-sharing octahedral tilt angles are 66°. In the third O site, O(6) is bonded in a 4-coordinate geometry to two equivalent La(2), two equivalent La(3), one Ti(2), and one Ga(1) atom. In the fourth O site, O(7) is bonded to three equivalent La(1) and one Ti(1) atom to form OLa3Ti tetrahedra that share  a cornercorner with one O(5)La2Ti2 tetrahedra and corners with six equivalent O(7)La3Ti tetrahedra. In the fifth O site, O(8) is bonded in a 2-coordinate geometry to two equivalent La(3), one Ti(1), and one Ti(2) atom. In the sixth O site, O(1) is bonded in a 4-coordinate geometry to three equivalent La(1) and one Ti(1) atom. In the seventh O site, O(9) is bonded to two equivalent La(2), two equivalent La(3), and two equivalent Ga(1) atoms to form distorted OLa4Ga2 octahedra that share corners with four equivalent O(9)La4Ga2 octahedra, corners with four equivalent O(5)La2Ti2 tetrahedra, and edges with four equivalent O(3)La3Ti2 square pyramids. The corner-sharing octahedra are not tilted. In the eighth O site, O(2) is bonded in a 4-coordinate geometry to two equivalent La(2), two equivalent La(3), one Ti(2), and one Ga(1) atom. In the ninth O site, O(3) is bonded to one La(2), two equivalent La(3), and two equivalent Ti(2) atoms to form distorted OLa3Ti2 square pyramids that share corners with five equivalent O(3)La3Ti2 square pyramids, corners with two equivalent O(5)La2Ti2 tetrahedra, edges with two equivalent O(9)La4Ga2 octahedra, and edges with two equivalent O(5)La2Ti2 tetrahedra.