La4C2I5 crystallizes in the monoclinic C2/m space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 8-coordinate geometry to four equivalent C(1), one I(1), one I(3), and two equivalent I(2) atoms. In the second La site, La(2) is bonded to one C(1), two equivalent I(1), and three equivalent I(3) atoms to form distorted edge-sharing LaCI5 octahedra. C(1) is bonded in a 6-coordinate geometry to one La(2), four equivalent La(1), and one C(1) atom. There are three inequivalent I sites. In the first I site, I(1) is bonded in a 3-coordinate geometry to one La(1) and two equivalent La(2) atoms. In the second I site, I(2) is bonded in a distorted rectangular see-saw-like geometry to four equivalent La(1) atoms. In the third I site, I(3) is bonded in a rectangular see-saw-like geometry to one La(1) and three equivalent La(2) atoms.
La4C2I5 crystallizes in the monoclinic C2/m space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 8-coordinate geometry to four equivalent C(1), one I(1), one I(3), and two equivalent I(2) atoms. All La(1)-C(1) bond lengths are 2.78 Å. The La(1)-I(1) bond length is 3.31 Å. The La(1)-I(3) bond length is 3.40 Å. Both La(1)-I(2) bond lengths are 3.45 Å. In the second La site, La(2) is bonded to one C(1), two equivalent I(1), and three equivalent I(3) atoms to form distorted edge-sharing LaCI5 octahedra. The La(2)-C(1) bond length is 2.32 Å. Both La(2)-I(1) bond lengths are 3.21 Å. There are two shorter (3.27 Å) and one longer (3.58 Å) La(2)-I(3) bond length. C(1) is bonded in a 6-coordinate geometry to one La(2), four equivalent La(1), and one C(1) atom. The C(1)-C(1) bond length is 1.40 Å. There are three inequivalent I sites. In the first I site, I(1) is bonded in a 3-coordinate geometry to one La(1) and two equivalent La(2) atoms. In the second I site, I(2) is bonded in a distorted rectangular see-saw-like geometry to four equivalent La(1) atoms. In the third I site, I(3) is bonded in a rectangular see-saw-like geometry to one La(1) and three equivalent La(2) atoms.