BaLaI5 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to one I(1), one I(10), one I(2), one I(3), one I(4), one I(5), one I(6), and one I(7) atom. In the second Ba site, Ba(2) is bonded to one I(1), one I(2), one I(4), one I(5), one I(6), one I(8), and one I(9) atom to form distorted BaI7 pentagonal bipyramids that share corners with three equivalent La(2)I6 octahedra, corners with two equivalent La(1)I7 pentagonal bipyramids, and edges with two equivalent La(1)I7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 55-64°. There are two inequivalent La sites. In the first La site, La(1) is bonded to one I(1), one I(2), one I(3), one I(4), one I(6), one I(8), and one I(9) atom to form distorted LaI7 pentagonal bipyramids that share  a cornercorner with one La(2)I6 octahedra, corners with two equivalent Ba(2)I7 pentagonal bipyramids,  an edgeedge with one La(2)I6 octahedra, and edges with two equivalent Ba(2)I7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 67°. In the second La site, La(2) is bonded to one I(10), one I(3), one I(5), one I(7), one I(8), and one I(9) atom to form LaI6 octahedra that share  a cornercorner with one La(1)I7 pentagonal bipyramid, corners with three equivalent Ba(2)I7 pentagonal bipyramids, and  an edgeedge with one La(1)I7 pentagonal bipyramid. There are ten inequivalent I sites. In the first I site, I(1) is bonded in a 3-coordinate geometry to one Ba(1), one Ba(2), and one La(1) atom. In the second I site, I(2) is bonded in a distorted L-shaped geometry to one Ba(1), one Ba(2), and one La(1) atom. In the third I site, I(3) is bonded in a distorted trigonal planar geometry to one Ba(1), one La(1), and one La(2) atom. In the fourth I site, I(4) is bonded in a T-shaped geometry to one Ba(1), one Ba(2), and one La(1) atom. In the fifth I site, I(5) is bonded in a trigonal planar geometry to one Ba(1), one Ba(2), and one La(2) atom. In the sixth I site, I(6) is bonded in a distorted T-shaped geometry to one Ba(1), one Ba(2), and one La(1) atom. In the seventh I site, I(7) is bonded in a bent 120 degrees geometry to one Ba(1) and one La(2) atom. In the eighth I site, I(8) is bonded in a trigonal planar geometry to one Ba(2), one La(1), and one La(2) atom. In the ninth I site, I(9) is bonded in a trigonal non-coplanar geometry to one Ba(2), one La(1), and one La(2) atom. In the tenth I site, I(10) is bonded in a bent 120 degrees geometry to one Ba(1) and one La(2) atom.
BaLaI5 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to one I(1), one I(10), one I(2), one I(3), one I(4), one I(5), one I(6), and one I(7) atom. The Ba(1)-I(1) bond length is 4.00 Å. The Ba(1)-I(10) bond length is 3.55 Å. The Ba(1)-I(2) bond length is 4.26 Å. The Ba(1)-I(3) bond length is 4.01 Å. The Ba(1)-I(4) bond length is 3.65 Å. The Ba(1)-I(5) bond length is 3.61 Å. The Ba(1)-I(6) bond length is 3.44 Å. The Ba(1)-I(7) bond length is 3.43 Å. In the second Ba site, Ba(2) is bonded to one I(1), one I(2), one I(4), one I(5), one I(6), one I(8), and one I(9) atom to form distorted BaI7 pentagonal bipyramids that share corners with three equivalent La(2)I6 octahedra, corners with two equivalent La(1)I7 pentagonal bipyramids, and edges with two equivalent La(1)I7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 55-64°. The Ba(2)-I(1) bond length is 3.50 Å. The Ba(2)-I(2) bond length is 3.55 Å. The Ba(2)-I(4) bond length is 3.51 Å. The Ba(2)-I(5) bond length is 3.60 Å. The Ba(2)-I(6) bond length is 3.57 Å. The Ba(2)-I(8) bond length is 3.87 Å. The Ba(2)-I(9) bond length is 3.68 Å. There are two inequivalent La sites. In the first La site, La(1) is bonded to one I(1), one I(2), one I(3), one I(4), one I(6), one I(8), and one I(9) atom to form distorted LaI7 pentagonal bipyramids that share  a cornercorner with one La(2)I6 octahedra, corners with two equivalent Ba(2)I7 pentagonal bipyramids,  an edgeedge with one La(2)I6 octahedra, and edges with two equivalent Ba(2)I7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 67°. The La(1)-I(1) bond length is 3.17 Å. The La(1)-I(2) bond length is 3.21 Å. The La(1)-I(3) bond length is 3.24 Å. The La(1)-I(4) bond length is 3.20 Å. The La(1)-I(6) bond length is 3.22 Å. The La(1)-I(8) bond length is 3.53 Å. The La(1)-I(9) bond length is 3.33 Å. In the second La site, La(2) is bonded to one I(10), one I(3), one I(5), one I(7), one I(8), and one I(9) atom to form LaI6 octahedra that share  a cornercorner with one La(1)I7 pentagonal bipyramid, corners with three equivalent Ba(2)I7 pentagonal bipyramids, and  an edgeedge with one La(1)I7 pentagonal bipyramid. The La(2)-I(10) bond length is 3.09 Å. The La(2)-I(3) bond length is 3.29 Å. The La(2)-I(5) bond length is 3.25 Å. The La(2)-I(7) bond length is 3.09 Å. The La(2)-I(8) bond length is 3.23 Å. The La(2)-I(9) bond length is 3.24 Å. There are ten inequivalent I sites. In the first I site, I(1) is bonded in a 3-coordinate geometry to one Ba(1), one Ba(2), and one La(1) atom. In the second I site, I(2) is bonded in a distorted L-shaped geometry to one Ba(1), one Ba(2), and one La(1) atom. In the third I site, I(3) is bonded in a distorted trigonal planar geometry to one Ba(1), one La(1), and one La(2) atom. In the fourth I site, I(4) is bonded in a T-shaped geometry to one Ba(1), one Ba(2), and one La(1) atom. In the fifth I site, I(5) is bonded in a trigonal planar geometry to one Ba(1), one Ba(2), and one La(2) atom. In the sixth I site, I(6) is bonded in a distorted T-shaped geometry to one Ba(1), one Ba(2), and one La(1) atom. In the seventh I site, I(7) is bonded in a bent 120 degrees geometry to one Ba(1) and one La(2) atom. In the eighth I site, I(8) is bonded in a trigonal planar geometry to one Ba(2), one La(1), and one La(2) atom. In the ninth I site, I(9) is bonded in a trigonal non-coplanar geometry to one Ba(2), one La(1), and one La(2) atom. In the tenth I site, I(10) is bonded in a bent 120 degrees geometry to one Ba(1) and one La(2) atom.