Cs2La10Os2I17 crystallizes in the monoclinic C2/m space group. Cs(1) is bonded in a 12-coordinate geometry to two equivalent I(2), two equivalent I(3), two equivalent I(4), two equivalent I(5), and four equivalent I(1) atoms. There are four inequivalent La sites. In the first La site, La(1) is bonded to one Os(1), one I(1), two equivalent I(2), and two equivalent I(4) atoms to form LaOsI5 octahedra that share  a cornercorner with one La(1)OsI5 octahedra,  a cornercorner with one La(2)OsI5 octahedra,  an edgeedge with one La(2)OsI5 octahedra,  an edgeedge with one La(4)OsI5 octahedra, edges with two equivalent La(3)Os2I4 octahedra, and edges with two equivalent La(1)OsI5 octahedra. The corner-sharing octahedral tilt angles range from 1-9°. In the second La site, La(2) is bonded to one Os(1), one I(5), two equivalent I(2), and two equivalent I(3) atoms to form distorted LaOsI5 octahedra that share  a cornercorner with one La(3)Os2I4 octahedra, corners with two equivalent La(1)OsI5 octahedra, corners with two equivalent La(4)OsI5 octahedra,  an edgeedge with one La(3)Os2I4 octahedra,  an edgeedge with one La(2)OsI5 octahedra,  an edgeedge with one La(4)OsI5 octahedra, and edges with two equivalent La(1)OsI5 octahedra. The corner-sharing octahedral tilt angles range from 6-11°. In the third La site, La(3) is bonded to two equivalent Os(1), one I(5), one I(6), and two equivalent I(4) atoms to form distorted LaOs2I4 octahedra that share  a cornercorner with one La(3)Os2I4 octahedra,  a cornercorner with one La(2)OsI5 octahedra,  a cornercorner with one La(4)OsI5 octahedra,  an edgeedge with one La(3)Os2I4 octahedra,  an edgeedge with one La(2)OsI5 octahedra, edges with two equivalent La(4)OsI5 octahedra, and edges with four equivalent La(1)OsI5 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. In the fourth La site, La(4) is bonded to one Os(1), one I(3), one I(5), one I(6), and two equivalent I(1) atoms to form distorted LaOsI5 octahedra that share  a cornercorner with one La(3)Os2I4 octahedra,  a cornercorner with one La(4)OsI5 octahedra, corners with two equivalent La(2)OsI5 octahedra,  an edgeedge with one La(2)OsI5 octahedra, edges with two equivalent La(3)Os2I4 octahedra, and edges with two equivalent La(1)OsI5 octahedra. The corner-sharing octahedral tilt angles range from 0-11°. Os(1) is bonded to one La(2), one La(4), two equivalent La(1), and two equivalent La(3) atoms to form edge-sharing OsLa6 octahedra. There are six inequivalent I sites. In the first I site, I(2) is bonded in a distorted T-shaped geometry to one Cs(1), one La(2), and two equivalent La(1) atoms. In the second I site, I(3) is bonded in a distorted T-shaped geometry to two equivalent Cs(1), one La(4), and two equivalent La(2) atoms. In the third I site, I(4) is bonded in a 4-coordinate geometry to one Cs(1), one La(3), and two equivalent La(1) atoms. In the fourth I site, I(5) is bonded in a 3-coordinate geometry to two equivalent Cs(1), one La(2), one La(3), and one La(4) atom. In the fifth I site, I(6) is bonded in a distorted square co-planar geometry to two equivalent La(3) and two equivalent La(4) atoms. In the sixth I site, I(1) is bonded in a 2-coordinate geometry to two equivalent Cs(1), one La(1), and one La(4) atom.
Cs2La10Os2I17 crystallizes in the monoclinic C2/m space group. Cs(1) is bonded in a 12-coordinate geometry to two equivalent I(2), two equivalent I(3), two equivalent I(4), two equivalent I(5), and four equivalent I(1) atoms. Both Cs(1)-I(2) bond lengths are 4.54 Å. Both Cs(1)-I(3) bond lengths are 4.55 Å. Both Cs(1)-I(4) bond lengths are 4.23 Å. Both Cs(1)-I(5) bond lengths are 4.59 Å. There are two shorter (4.34 Å) and two longer (4.45 Å) Cs(1)-I(1) bond lengths. There are four inequivalent La sites. In the first La site, La(1) is bonded to one Os(1), one I(1), two equivalent I(2), and two equivalent I(4) atoms to form LaOsI5 octahedra that share  a cornercorner with one La(1)OsI5 octahedra,  a cornercorner with one La(2)OsI5 octahedra,  an edgeedge with one La(2)OsI5 octahedra,  an edgeedge with one La(4)OsI5 octahedra, edges with two equivalent La(3)Os2I4 octahedra, and edges with two equivalent La(1)OsI5 octahedra. The corner-sharing octahedral tilt angles range from 1-9°. The La(1)-Os(1) bond length is 2.90 Å. The La(1)-I(1) bond length is 3.23 Å. There is one shorter (3.31 Å) and one longer (3.49 Å) La(1)-I(2) bond length. Both La(1)-I(4) bond lengths are 3.32 Å. In the second La site, La(2) is bonded to one Os(1), one I(5), two equivalent I(2), and two equivalent I(3) atoms to form distorted LaOsI5 octahedra that share  a cornercorner with one La(3)Os2I4 octahedra, corners with two equivalent La(1)OsI5 octahedra, corners with two equivalent La(4)OsI5 octahedra,  an edgeedge with one La(3)Os2I4 octahedra,  an edgeedge with one La(2)OsI5 octahedra,  an edgeedge with one La(4)OsI5 octahedra, and edges with two equivalent La(1)OsI5 octahedra. The corner-sharing octahedral tilt angles range from 6-11°. The La(2)-Os(1) bond length is 2.82 Å. The La(2)-I(5) bond length is 3.28 Å. Both La(2)-I(2) bond lengths are 3.30 Å. There is one shorter (3.31 Å) and one longer (3.53 Å) La(2)-I(3) bond length. In the third La site, La(3) is bonded to two equivalent Os(1), one I(5), one I(6), and two equivalent I(4) atoms to form distorted LaOs2I4 octahedra that share  a cornercorner with one La(3)Os2I4 octahedra,  a cornercorner with one La(2)OsI5 octahedra,  a cornercorner with one La(4)OsI5 octahedra,  an edgeedge with one La(3)Os2I4 octahedra,  an edgeedge with one La(2)OsI5 octahedra, edges with two equivalent La(4)OsI5 octahedra, and edges with four equivalent La(1)OsI5 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. There is one shorter (2.87 Å) and one longer (3.01 Å) La(3)-Os(1) bond length. The La(3)-I(5) bond length is 3.56 Å. The La(3)-I(6) bond length is 3.46 Å. Both La(3)-I(4) bond lengths are 3.40 Å. In the fourth La site, La(4) is bonded to one Os(1), one I(3), one I(5), one I(6), and two equivalent I(1) atoms to form distorted LaOsI5 octahedra that share  a cornercorner with one La(3)Os2I4 octahedra,  a cornercorner with one La(4)OsI5 octahedra, corners with two equivalent La(2)OsI5 octahedra,  an edgeedge with one La(2)OsI5 octahedra, edges with two equivalent La(3)Os2I4 octahedra, and edges with two equivalent La(1)OsI5 octahedra. The corner-sharing octahedral tilt angles range from 0-11°. The La(4)-Os(1) bond length is 2.74 Å. The La(4)-I(3) bond length is 3.31 Å. The La(4)-I(5) bond length is 3.50 Å. The La(4)-I(6) bond length is 3.30 Å. Both La(4)-I(1) bond lengths are 3.28 Å. Os(1) is bonded to one La(2), one La(4), two equivalent La(1), and two equivalent La(3) atoms to form edge-sharing OsLa6 octahedra. There are six inequivalent I sites. In the first I site, I(2) is bonded in a distorted T-shaped geometry to one Cs(1), one La(2), and two equivalent La(1) atoms. In the second I site, I(3) is bonded in a distorted T-shaped geometry to two equivalent Cs(1), one La(4), and two equivalent La(2) atoms. In the third I site, I(4) is bonded in a 4-coordinate geometry to one Cs(1), one La(3), and two equivalent La(1) atoms. In the fourth I site, I(5) is bonded in a 3-coordinate geometry to two equivalent Cs(1), one La(2), one La(3), and one La(4) atom. In the fifth I site, I(6) is bonded in a distorted square co-planar geometry to two equivalent La(3) and two equivalent La(4) atoms. In the sixth I site, I(1) is bonded in a 2-coordinate geometry to two equivalent Cs(1), one La(1), and one La(4) atom.