Cs2Li3I5 crystallizes in the triclinic P1 space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 8-coordinate geometry to one I(3), one I(4), two equivalent I(1), two equivalent I(2), and two equivalent I(5) atoms. In the second Cs site, Cs(2) is bonded in a 8-coordinate geometry to one I(1), one I(2), two equivalent I(3), two equivalent I(4), and two equivalent I(5) atoms. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one I(3), one I(5), and two equivalent I(4) atoms to form LiI4 tetrahedra that share  a cornercorner with one Li(3)I4 tetrahedra, corners with two equivalent Li(1)I4 tetrahedra, and edges with two equivalent Li(2)I6 octahedra. In the second Li site, Li(2) is bonded to one I(1), one I(4), two equivalent I(2), and two equivalent I(3) atoms to form LiI6 octahedra that share edges with two equivalent Li(2)I6 octahedra, edges with two equivalent Li(1)I4 tetrahedra, and edges with two equivalent Li(3)I4 tetrahedra. In the third Li site, Li(3) is bonded to one I(2), one I(5), and two equivalent I(1) atoms to form LiI4 tetrahedra that share  a cornercorner with one Li(1)I4 tetrahedra, corners with two equivalent Li(3)I4 tetrahedra, and edges with two equivalent Li(2)I6 octahedra. There are five inequivalent I sites. In the first I site, I(1) is bonded in a 6-coordinate geometry to one Cs(2), two equivalent Cs(1), one Li(2), and two equivalent Li(3) atoms. In the second I site, I(2) is bonded in a 6-coordinate geometry to one Cs(2), two equivalent Cs(1), one Li(3), and two equivalent Li(2) atoms. In the third I site, I(3) is bonded in a 6-coordinate geometry to one Cs(1), two equivalent Cs(2), one Li(1), and two equivalent Li(2) atoms. In the fourth I site, I(4) is bonded in a 6-coordinate geometry to one Cs(1), two equivalent Cs(2), one Li(2), and two equivalent Li(1) atoms. In the fifth I site, I(5) is bonded to two equivalent Cs(1), two equivalent Cs(2), one Li(1), and one Li(3) atom to form distorted edge-sharing ICs4Li2 octahedra.
Cs2Li3I5 crystallizes in the triclinic P1 space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 8-coordinate geometry to one I(3), one I(4), two equivalent I(1), two equivalent I(2), and two equivalent I(5) atoms. The Cs(1)-I(3) bond length is 3.88 Å. The Cs(1)-I(4) bond length is 4.40 Å. Both Cs(1)-I(1) bond lengths are 3.91 Å. Both Cs(1)-I(2) bond lengths are 3.97 Å. Both Cs(1)-I(5) bond lengths are 3.84 Å. In the second Cs site, Cs(2) is bonded in a 8-coordinate geometry to one I(1), one I(2), two equivalent I(3), two equivalent I(4), and two equivalent I(5) atoms. The Cs(2)-I(1) bond length is 4.39 Å. The Cs(2)-I(2) bond length is 3.89 Å. Both Cs(2)-I(3) bond lengths are 3.96 Å. There is one shorter (3.91 Å) and one longer (3.92 Å) Cs(2)-I(4) bond length. Both Cs(2)-I(5) bond lengths are 3.85 Å. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one I(3), one I(5), and two equivalent I(4) atoms to form LiI4 tetrahedra that share  a cornercorner with one Li(3)I4 tetrahedra, corners with two equivalent Li(1)I4 tetrahedra, and edges with two equivalent Li(2)I6 octahedra. The Li(1)-I(3) bond length is 2.72 Å. The Li(1)-I(5) bond length is 2.75 Å. Both Li(1)-I(4) bond lengths are 2.76 Å. In the second Li site, Li(2) is bonded to one I(1), one I(4), two equivalent I(2), and two equivalent I(3) atoms to form LiI6 octahedra that share edges with two equivalent Li(2)I6 octahedra, edges with two equivalent Li(1)I4 tetrahedra, and edges with two equivalent Li(3)I4 tetrahedra. The Li(2)-I(1) bond length is 3.17 Å. The Li(2)-I(4) bond length is 3.10 Å. There is one shorter (3.12 Å) and one longer (3.16 Å) Li(2)-I(2) bond length. There is one shorter (3.13 Å) and one longer (3.18 Å) Li(2)-I(3) bond length. In the third Li site, Li(3) is bonded to one I(2), one I(5), and two equivalent I(1) atoms to form LiI4 tetrahedra that share  a cornercorner with one Li(1)I4 tetrahedra, corners with two equivalent Li(3)I4 tetrahedra, and edges with two equivalent Li(2)I6 octahedra. The Li(3)-I(2) bond length is 2.72 Å. The Li(3)-I(5) bond length is 2.76 Å. There is one shorter (2.76 Å) and one longer (2.77 Å) Li(3)-I(1) bond length. There are five inequivalent I sites. In the first I site, I(1) is bonded in a 6-coordinate geometry to one Cs(2), two equivalent Cs(1), one Li(2), and two equivalent Li(3) atoms. In the second I site, I(2) is bonded in a 6-coordinate geometry to one Cs(2), two equivalent Cs(1), one Li(3), and two equivalent Li(2) atoms. In the third I site, I(3) is bonded in a 6-coordinate geometry to one Cs(1), two equivalent Cs(2), one Li(1), and two equivalent Li(2) atoms. In the fourth I site, I(4) is bonded in a 6-coordinate geometry to one Cs(1), two equivalent Cs(2), one Li(2), and two equivalent Li(1) atoms. In the fifth I site, I(5) is bonded to two equivalent Cs(1), two equivalent Cs(2), one Li(1), and one Li(3) atom to form distorted edge-sharing ICs4Li2 octahedra.