Ba2LaI7 crystallizes in the monoclinic C2/c space group. Ba(1) is bonded in a 8-coordinate geometry to one I(4), two equivalent I(1), two equivalent I(3), and three equivalent I(2) atoms. La(1) is bonded in a 9-coordinate geometry to one I(4), two equivalent I(2), two equivalent I(3), and four equivalent I(1) atoms. There are four inequivalent I sites. In the first I site, I(1) is bonded to two equivalent Ba(1) and two equivalent La(1) atoms to form IBa2La2 tetrahedra that share corners with four equivalent I(2)Ba3La tetrahedra, corners with six equivalent I(1)Ba2La2 tetrahedra,  an edgeedge with one I(1)Ba2La2 tetrahedra, and edges with three equivalent I(2)Ba3La tetrahedra. In the second I site, I(2) is bonded to three equivalent Ba(1) and one La(1) atom to form IBa3La tetrahedra that share corners with four equivalent I(1)Ba2La2 tetrahedra, corners with five equivalent I(2)Ba3La tetrahedra,  an edgeedge with one I(2)Ba3La tetrahedra, and edges with three equivalent I(1)Ba2La2 tetrahedra. In the third I site, I(3) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ba(1) and one La(1) atom. In the fourth I site, I(4) is bonded in a distorted trigonal planar geometry to two equivalent Ba(1) and one La(1) atom.
Ba2LaI7 crystallizes in the monoclinic C2/c space group. Ba(1) is bonded in a 8-coordinate geometry to one I(4), two equivalent I(1), two equivalent I(3), and three equivalent I(2) atoms. The Ba(1)-I(4) bond length is 3.55 Å. There is one shorter (3.72 Å) and one longer (3.90 Å) Ba(1)-I(1) bond length. There is one shorter (3.57 Å) and one longer (3.61 Å) Ba(1)-I(3) bond length. There are a spread of Ba(1)-I(2) bond distances ranging from 3.51-3.61 Å. La(1) is bonded in a 9-coordinate geometry to one I(4), two equivalent I(2), two equivalent I(3), and four equivalent I(1) atoms. The La(1)-I(4) bond length is 3.41 Å. Both La(1)-I(2) bond lengths are 3.31 Å. Both La(1)-I(3) bond lengths are 3.36 Å. There are two shorter (3.53 Å) and two longer (3.57 Å) La(1)-I(1) bond lengths. There are four inequivalent I sites. In the first I site, I(1) is bonded to two equivalent Ba(1) and two equivalent La(1) atoms to form IBa2La2 tetrahedra that share corners with four equivalent I(2)Ba3La tetrahedra, corners with six equivalent I(1)Ba2La2 tetrahedra,  an edgeedge with one I(1)Ba2La2 tetrahedra, and edges with three equivalent I(2)Ba3La tetrahedra. In the second I site, I(2) is bonded to three equivalent Ba(1) and one La(1) atom to form IBa3La tetrahedra that share corners with four equivalent I(1)Ba2La2 tetrahedra, corners with five equivalent I(2)Ba3La tetrahedra,  an edgeedge with one I(2)Ba3La tetrahedra, and edges with three equivalent I(1)Ba2La2 tetrahedra. In the third I site, I(3) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ba(1) and one La(1) atom. In the fourth I site, I(4) is bonded in a distorted trigonal planar geometry to two equivalent Ba(1) and one La(1) atom.