BaLa4Ti4O15 is Krennerite-derived structured and crystallizes in the trigonal P3c1 space group. Ba(1) is bonded to three equivalent O(3), three equivalent O(5), and six equivalent O(2) atoms to form distorted BaO12 cuboctahedra that share corners with six equivalent Ba(1)O12 cuboctahedra, corners with three equivalent Ti(1)O6 octahedra,  a faceface with one Ti(3)O6 octahedra, and faces with three equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles are 37°. There are four inequivalent La sites. In the first La site, La(1) is bonded in a 6-coordinate geometry to three equivalent O(3) and three equivalent O(4) atoms. In the second La site, La(2) is bonded in a 6-coordinate geometry to three equivalent O(2) and six equivalent O(5) atoms. In the third La site, La(3) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(4), and three equivalent O(5) atoms. In the fourth La site, La(4) is bonded in a 6-coordinate geometry to three equivalent O(2) and three equivalent O(3) atoms. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to three equivalent O(3) and three equivalent O(4) atoms to form distorted TiO6 octahedra that share corners with three equivalent Ba(1)O12 cuboctahedra and corners with three equivalent Ti(4)O6 octahedra. The corner-sharing octahedral tilt angles are 22°. In the second Ti site, Ti(2) is bonded to three equivalent O(2) and three equivalent O(5) atoms to form distorted TiO6 octahedra that share corners with three equivalent Ti(3)O6 octahedra and faces with three equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 20°. In the third Ti site, Ti(3) is bonded to three equivalent O(1) and three equivalent O(5) atoms to form TiO6 octahedra that share corners with three equivalent Ti(2)O6 octahedra, corners with three equivalent Ti(4)O6 octahedra, and  a faceface with one Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 20°. In the fourth Ti site, Ti(4) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 20-22°. There are five inequivalent O sites. In the first O site, O(4) is bonded in a 4-coordinate geometry to one La(1), one La(3), one Ti(1), and one Ti(4) atom. In the second O site, O(5) is bonded in a 6-coordinate geometry to one Ba(1), one La(3), two equivalent La(2), one Ti(2), and one Ti(3) atom. In the third O site, O(1) is bonded in a 3-coordinate geometry to one La(3), one Ti(3), and one Ti(4) atom. In the fourth O site, O(2) is bonded in a distorted single-bond geometry to two equivalent Ba(1), one La(2), one La(4), and one Ti(2) atom. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one Ba(1), one La(1), one La(4), and one Ti(1) atom.
BaLa4Ti4O15 is Krennerite-derived structured and crystallizes in the trigonal P3c1 space group. Ba(1) is bonded to three equivalent O(3), three equivalent O(5), and six equivalent O(2) atoms to form distorted BaO12 cuboctahedra that share corners with six equivalent Ba(1)O12 cuboctahedra, corners with three equivalent Ti(1)O6 octahedra,  a faceface with one Ti(3)O6 octahedra, and faces with three equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles are 37°. All Ba(1)-O(3) bond lengths are 2.82 Å. All Ba(1)-O(5) bond lengths are 3.10 Å. There are three shorter (2.71 Å) and three longer (2.96 Å) Ba(1)-O(2) bond lengths. There are four inequivalent La sites. In the first La site, La(1) is bonded in a 6-coordinate geometry to three equivalent O(3) and three equivalent O(4) atoms. All La(1)-O(3) bond lengths are 2.53 Å. All La(1)-O(4) bond lengths are 2.48 Å. In the second La site, La(2) is bonded in a 6-coordinate geometry to three equivalent O(2) and six equivalent O(5) atoms. All La(2)-O(2) bond lengths are 2.52 Å. There are three shorter (2.52 Å) and three longer (3.14 Å) La(2)-O(5) bond lengths. In the third La site, La(3) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(4), and three equivalent O(5) atoms. All La(3)-O(1) bond lengths are 2.47 Å. All La(3)-O(4) bond lengths are 2.74 Å. All La(3)-O(5) bond lengths are 2.70 Å. In the fourth La site, La(4) is bonded in a 6-coordinate geometry to three equivalent O(2) and three equivalent O(3) atoms. All La(4)-O(2) bond lengths are 2.55 Å. All La(4)-O(3) bond lengths are 2.44 Å. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to three equivalent O(3) and three equivalent O(4) atoms to form distorted TiO6 octahedra that share corners with three equivalent Ba(1)O12 cuboctahedra and corners with three equivalent Ti(4)O6 octahedra. The corner-sharing octahedral tilt angles are 22°. All Ti(1)-O(3) bond lengths are 1.86 Å. All Ti(1)-O(4) bond lengths are 2.17 Å. In the second Ti site, Ti(2) is bonded to three equivalent O(2) and three equivalent O(5) atoms to form distorted TiO6 octahedra that share corners with three equivalent Ti(3)O6 octahedra and faces with three equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 20°. All Ti(2)-O(2) bond lengths are 1.85 Å. All Ti(2)-O(5) bond lengths are 2.18 Å. In the third Ti site, Ti(3) is bonded to three equivalent O(1) and three equivalent O(5) atoms to form TiO6 octahedra that share corners with three equivalent Ti(2)O6 octahedra, corners with three equivalent Ti(4)O6 octahedra, and  a faceface with one Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 20°. All Ti(3)-O(1) bond lengths are 2.03 Å. All Ti(3)-O(5) bond lengths are 1.94 Å. In the fourth Ti site, Ti(4) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 20-22°. All Ti(4)-O(1) bond lengths are 2.04 Å. All Ti(4)-O(4) bond lengths are 1.94 Å. There are five inequivalent O sites. In the first O site, O(4) is bonded in a 4-coordinate geometry to one La(1), one La(3), one Ti(1), and one Ti(4) atom. In the second O site, O(5) is bonded in a 6-coordinate geometry to one Ba(1), one La(3), two equivalent La(2), one Ti(2), and one Ti(3) atom. In the third O site, O(1) is bonded in a 3-coordinate geometry to one La(3), one Ti(3), and one Ti(4) atom. In the fourth O site, O(2) is bonded in a distorted single-bond geometry to two equivalent Ba(1), one La(2), one La(4), and one Ti(2) atom. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one Ba(1), one La(1), one La(4), and one Ti(1) atom.