Sr2LaI7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one I(1), one I(3), one I(4), one I(5), one I(7), two equivalent I(2), and two equivalent I(6) atoms. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one I(1), one I(2), one I(3), one I(4), one I(5), one I(6), and two equivalent I(7) atoms. La(1) is bonded in a distorted pentagonal bipyramidal geometry to one I(1), one I(2), one I(3), one I(4), one I(5), one I(6), and one I(7) atom. There are seven inequivalent I sites. In the first I site, I(1) is bonded in a trigonal non-coplanar geometry to one Sr(1), one Sr(2), and one La(1) atom. In the second I site, I(2) is bonded to one Sr(2), two equivalent Sr(1), and one La(1) atom to form a mixture of distorted corner and edge-sharing ISr3La tetrahedra. In the third I site, I(3) is bonded in a distorted trigonal non-coplanar geometry to one Sr(1), one Sr(2), and one La(1) atom. In the fourth I site, I(4) is bonded in a 3-coordinate geometry to one Sr(1), one Sr(2), and one La(1) atom. In the fifth I site, I(5) is bonded in a distorted trigonal non-coplanar geometry to one Sr(1), one Sr(2), and one La(1) atom. In the sixth I site, I(6) is bonded to one Sr(2), two equivalent Sr(1), and one La(1) atom to form a mixture of corner and edge-sharing ISr3La tetrahedra. In the seventh I site, I(7) is bonded to one Sr(1), two equivalent Sr(2), and one La(1) atom to form a mixture of corner and edge-sharing ISr3La tetrahedra.
Sr2LaI7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one I(1), one I(3), one I(4), one I(5), one I(7), two equivalent I(2), and two equivalent I(6) atoms. The Sr(1)-I(1) bond length is 3.55 Å. The Sr(1)-I(3) bond length is 3.52 Å. The Sr(1)-I(4) bond length is 3.72 Å. The Sr(1)-I(5) bond length is 3.44 Å. The Sr(1)-I(7) bond length is 3.61 Å. There is one shorter (3.67 Å) and one longer (3.91 Å) Sr(1)-I(2) bond length. There is one shorter (3.52 Å) and one longer (3.59 Å) Sr(1)-I(6) bond length. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one I(1), one I(2), one I(3), one I(4), one I(5), one I(6), and two equivalent I(7) atoms. The Sr(2)-I(1) bond length is 3.54 Å. The Sr(2)-I(2) bond length is 3.91 Å. The Sr(2)-I(3) bond length is 3.49 Å. The Sr(2)-I(4) bond length is 3.43 Å. The Sr(2)-I(5) bond length is 3.61 Å. The Sr(2)-I(6) bond length is 3.52 Å. There is one shorter (3.42 Å) and one longer (3.44 Å) Sr(2)-I(7) bond length. La(1) is bonded in a distorted pentagonal bipyramidal geometry to one I(1), one I(2), one I(3), one I(4), one I(5), one I(6), and one I(7) atom. The La(1)-I(1) bond length is 3.23 Å. The La(1)-I(2) bond length is 3.18 Å. The La(1)-I(3) bond length is 3.28 Å. The La(1)-I(4) bond length is 3.20 Å. The La(1)-I(5) bond length is 3.17 Å. The La(1)-I(6) bond length is 3.36 Å. The La(1)-I(7) bond length is 3.27 Å. There are seven inequivalent I sites. In the first I site, I(1) is bonded in a trigonal non-coplanar geometry to one Sr(1), one Sr(2), and one La(1) atom. In the second I site, I(2) is bonded to one Sr(2), two equivalent Sr(1), and one La(1) atom to form a mixture of distorted corner and edge-sharing ISr3La tetrahedra. In the third I site, I(3) is bonded in a distorted trigonal non-coplanar geometry to one Sr(1), one Sr(2), and one La(1) atom. In the fourth I site, I(4) is bonded in a 3-coordinate geometry to one Sr(1), one Sr(2), and one La(1) atom. In the fifth I site, I(5) is bonded in a distorted trigonal non-coplanar geometry to one Sr(1), one Sr(2), and one La(1) atom. In the sixth I site, I(6) is bonded to one Sr(2), two equivalent Sr(1), and one La(1) atom to form a mixture of corner and edge-sharing ISr3La tetrahedra. In the seventh I site, I(7) is bonded to one Sr(1), two equivalent Sr(2), and one La(1) atom to form a mixture of corner and edge-sharing ISr3La tetrahedra.