La10Os2I15 crystallizes in the triclinic P-1 space group. There are five inequivalent La sites. In the first La site, La(1) is bonded to two equivalent Os(1), one I(1), one I(2), one I(6), and one I(8) atom to form distorted LaOs2I4 octahedra that share  a cornercorner with one La(1)Os2I4 octahedra,  a cornercorner with one La(2)OsI5 octahedra,  a cornercorner with one La(4)OsI5 octahedra,  an edgeedge with one La(1)Os2I4 octahedra,  an edgeedge with one La(2)OsI5 octahedra, edges with two equivalent La(3)OsI5 octahedra, edges with two equivalent La(4)OsI5 octahedra, and edges with two equivalent La(5)OsI5 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. In the second La site, La(2) is bonded to one Os(1), one I(5), one I(6), one I(7), and two equivalent I(4) atoms to form LaOsI5 octahedra that share  a cornercorner with one La(1)Os2I4 octahedra,  a cornercorner with one La(3)OsI5 octahedra, corners with two equivalent La(4)OsI5 octahedra,  an edgeedge with one La(1)Os2I4 octahedra,  an edgeedge with one La(2)OsI5 octahedra,  an edgeedge with one La(3)OsI5 octahedra,  an edgeedge with one La(4)OsI5 octahedra, and edges with two equivalent La(5)OsI5 octahedra. The corner-sharing octahedral tilt angles range from 5-11°. In the third La site, La(3) is bonded to one Os(1), one I(1), one I(2), one I(4), and two equivalent I(3) atoms to form LaOsI5 octahedra that share  a cornercorner with one La(2)OsI5 octahedra,  a cornercorner with one La(4)OsI5 octahedra,  a cornercorner with one La(5)OsI5 octahedra,  an edgeedge with one La(2)OsI5 octahedra,  an edgeedge with one La(3)OsI5 octahedra,  an edgeedge with one La(4)OsI5 octahedra,  an edgeedge with one La(5)OsI5 octahedra, and edges with two equivalent La(1)Os2I4 octahedra. The corner-sharing octahedral tilt angles range from 3-9°. In the fourth La site, La(4) is bonded to one Os(1), one I(3), one I(5), one I(6), one I(7), and one I(8) atom to form distorted LaOsI5 octahedra that share  a cornercorner with one La(1)Os2I4 octahedra,  a cornercorner with one La(3)OsI5 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,  an edgeedge with one La(3)OsI5 octahedra, edges with two equivalent La(1)Os2I4 octahedra, and edges with two equivalent La(5)OsI5 octahedra. The corner-sharing octahedral tilt angles range from 0-11°. In the fifth La site, La(5) is bonded to one Os(1), one I(1), one I(2), one I(7), and two equivalent I(5) atoms to form distorted LaOsI5 octahedra that share  a cornercorner with one La(3)OsI5 octahedra,  an edgeedge with one La(3)OsI5 octahedra,  an edgeedge with one La(5)OsI5 octahedra, edges with two equivalent La(1)Os2I4 octahedra, edges with two equivalent La(2)OsI5 octahedra, and edges with two equivalent La(4)OsI5 octahedra. The corner-sharing octahedral tilt angles are 3°. Os(1) is bonded to one La(2), one La(3), one La(4), one La(5), and two equivalent La(1) atoms to form edge-sharing OsLa6 octahedra. There are eight inequivalent I sites. In the first I site, I(1) is bonded in a distorted T-shaped geometry to one La(1), one La(3), and one La(5) atom. In the second I site, I(2) is bonded in a distorted T-shaped geometry to one La(1), one La(3), and one La(5) atom. In the third I site, I(3) is bonded in a distorted T-shaped geometry to one La(4) and two equivalent La(3) atoms. In the fourth I site, I(4) is bonded in a T-shaped geometry to one La(3) and two equivalent La(2) atoms. In the fifth I site, I(5) is bonded in a distorted rectangular see-saw-like geometry to one La(2), one La(4), and two equivalent La(5) atoms. In the sixth I site, I(6) is bonded in a distorted T-shaped geometry to one La(1), one La(2), and one La(4) atom. In the seventh I site, I(7) is bonded in a distorted T-shaped geometry to one La(2), one La(4), and one La(5) atom. In the eighth I site, I(8) is bonded in a square co-planar geometry to two equivalent La(1) and two equivalent La(4) atoms.
La10Os2I15 crystallizes in the triclinic P-1 space group. There are five inequivalent La sites. In the first La site, La(1) is bonded to two equivalent Os(1), one I(1), one I(2), one I(6), and one I(8) atom to form distorted LaOs2I4 octahedra that share  a cornercorner with one La(1)Os2I4 octahedra,  a cornercorner with one La(2)OsI5 octahedra,  a cornercorner with one La(4)OsI5 octahedra,  an edgeedge with one La(1)Os2I4 octahedra,  an edgeedge with one La(2)OsI5 octahedra, edges with two equivalent La(3)OsI5 octahedra, edges with two equivalent La(4)OsI5 octahedra, and edges with two equivalent La(5)OsI5 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. There is one shorter (2.86 Å) and one longer (3.10 Å) La(1)-Os(1) bond length. The La(1)-I(1) bond length is 3.35 Å. The La(1)-I(2) bond length is 3.35 Å. The La(1)-I(6) bond length is 3.41 Å. The La(1)-I(8) bond length is 3.50 Å. In the second La site, La(2) is bonded to one Os(1), one I(5), one I(6), one I(7), and two equivalent I(4) atoms to form LaOsI5 octahedra that share  a cornercorner with one La(1)Os2I4 octahedra,  a cornercorner with one La(3)OsI5 octahedra, corners with two equivalent La(4)OsI5 octahedra,  an edgeedge with one La(1)Os2I4 octahedra,  an edgeedge with one La(2)OsI5 octahedra,  an edgeedge with one La(3)OsI5 octahedra,  an edgeedge with one La(4)OsI5 octahedra, and edges with two equivalent La(5)OsI5 octahedra. The corner-sharing octahedral tilt angles range from 5-11°. The La(2)-Os(1) bond length is 2.87 Å. The La(2)-I(5) bond length is 3.35 Å. The La(2)-I(6) bond length is 3.24 Å. The La(2)-I(7) bond length is 3.27 Å. There is one shorter (3.24 Å) and one longer (3.50 Å) La(2)-I(4) bond length. In the third La site, La(3) is bonded to one Os(1), one I(1), one I(2), one I(4), and two equivalent I(3) atoms to form LaOsI5 octahedra that share  a cornercorner with one La(2)OsI5 octahedra,  a cornercorner with one La(4)OsI5 octahedra,  a cornercorner with one La(5)OsI5 octahedra,  an edgeedge with one La(2)OsI5 octahedra,  an edgeedge with one La(3)OsI5 octahedra,  an edgeedge with one La(4)OsI5 octahedra,  an edgeedge with one La(5)OsI5 octahedra, and edges with two equivalent La(1)Os2I4 octahedra. The corner-sharing octahedral tilt angles range from 3-9°. The La(3)-Os(1) bond length is 2.87 Å. The La(3)-I(1) bond length is 3.30 Å. The La(3)-I(2) bond length is 3.32 Å. The La(3)-I(4) bond length is 3.29 Å. There is one shorter (3.24 Å) and one longer (3.49 Å) La(3)-I(3) bond length. In the fourth La site, La(4) is bonded to one Os(1), one I(3), one I(5), one I(6), one I(7), and one I(8) atom to form distorted LaOsI5 octahedra that share  a cornercorner with one La(1)Os2I4 octahedra,  a cornercorner with one La(3)OsI5 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,  an edgeedge with one La(3)OsI5 octahedra, edges with two equivalent La(1)Os2I4 octahedra, and edges with two equivalent La(5)OsI5 octahedra. The corner-sharing octahedral tilt angles range from 0-11°. The La(4)-Os(1) bond length is 2.71 Å. The La(4)-I(3) bond length is 3.26 Å. The La(4)-I(5) bond length is 3.37 Å. The La(4)-I(6) bond length is 3.49 Å. The La(4)-I(7) bond length is 3.27 Å. The La(4)-I(8) bond length is 3.32 Å. In the fifth La site, La(5) is bonded to one Os(1), one I(1), one I(2), one I(7), and two equivalent I(5) atoms to form distorted LaOsI5 octahedra that share  a cornercorner with one La(3)OsI5 octahedra,  an edgeedge with one La(3)OsI5 octahedra,  an edgeedge with one La(5)OsI5 octahedra, edges with two equivalent La(1)Os2I4 octahedra, edges with two equivalent La(2)OsI5 octahedra, and edges with two equivalent La(4)OsI5 octahedra. The corner-sharing octahedral tilt angles are 3°. The La(5)-Os(1) bond length is 2.86 Å. The La(5)-I(1) bond length is 3.27 Å. The La(5)-I(2) bond length is 3.23 Å. The La(5)-I(7) bond length is 3.48 Å. There is one shorter (3.34 Å) and one longer (3.37 Å) La(5)-I(5) bond length. Os(1) is bonded to one La(2), one La(3), one La(4), one La(5), and two equivalent La(1) atoms to form edge-sharing OsLa6 octahedra. There are eight inequivalent I sites. In the first I site, I(1) is bonded in a distorted T-shaped geometry to one La(1), one La(3), and one La(5) atom. In the second I site, I(2) is bonded in a distorted T-shaped geometry to one La(1), one La(3), and one La(5) atom. In the third I site, I(3) is bonded in a distorted T-shaped geometry to one La(4) and two equivalent La(3) atoms. In the fourth I site, I(4) is bonded in a T-shaped geometry to one La(3) and two equivalent La(2) atoms. In the fifth I site, I(5) is bonded in a distorted rectangular see-saw-like geometry to one La(2), one La(4), and two equivalent La(5) atoms. In the sixth I site, I(6) is bonded in a distorted T-shaped geometry to one La(1), one La(2), and one La(4) atom. In the seventh I site, I(7) is bonded in a distorted T-shaped geometry to one La(2), one La(4), and one La(5) atom. In the eighth I site, I(8) is bonded in a square co-planar geometry to two equivalent La(1) and two equivalent La(4) atoms.