La3C3Cl2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent La sites. In the first La site, La(1) is bonded in a 7-coordinate geometry to one C(2), one C(3), two equivalent C(1), one Cl(1), and two equivalent Cl(2) atoms. In the second La site, La(2) is bonded in a 9-coordinate geometry to two equivalent C(1), two equivalent C(2), two equivalent C(3), one Cl(2), and two equivalent Cl(1) atoms. In the third La site, La(3) is bonded in a 8-coordinate geometry to one C(1), two equivalent C(2), two equivalent C(3), one Cl(1), and two equivalent Cl(2) atoms. There are three inequivalent C sites. In the first C site, C(1) is bonded in a 6-coordinate geometry to one La(3), two equivalent La(1), two equivalent La(2), and one C(2) atom. In the second C site, C(2) is bonded to one La(1), two equivalent La(2), two equivalent La(3), and one C(1) atom to form distorted CLa5C octahedra that share corners with two equivalent C(2)La5C octahedra, corners with four equivalent Cl(2)La5 trigonal bipyramids,  an edgeedge with one C(2)La5C octahedra, and edges with two equivalent Cl(2)La5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 66°. In the third C site, C(3) is bonded in a 6-coordinate geometry to one La(1), two equivalent La(2), two equivalent La(3), and one C(3) atom. There are two inequivalent Cl sites. In the first Cl site, Cl(1) is bonded in a rectangular see-saw-like geometry to one La(1), one La(3), and two equivalent La(2) atoms. In the second Cl site, Cl(2) is bonded to one La(2), two equivalent La(1), and two equivalent La(3) atoms to form distorted ClLa5 trigonal bipyramids that share corners with four equivalent C(2)La5C octahedra, edges with two equivalent C(2)La5C octahedra, and edges with two equivalent Cl(2)La5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 27-58°.
La3C3Cl2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent La sites. In the first La site, La(1) is bonded in a 7-coordinate geometry to one C(2), one C(3), two equivalent C(1), one Cl(1), and two equivalent Cl(2) atoms. The La(1)-C(2) bond length is 2.71 Å. The La(1)-C(3) bond length is 2.49 Å. There is one shorter (2.45 Å) and one longer (2.75 Å) La(1)-C(1) bond length. The La(1)-Cl(1) bond length is 3.14 Å. There is one shorter (3.21 Å) and one longer (3.22 Å) La(1)-Cl(2) bond length. In the second La site, La(2) is bonded in a 9-coordinate geometry to two equivalent C(1), two equivalent C(2), two equivalent C(3), one Cl(2), and two equivalent Cl(1) atoms. There is one shorter (2.65 Å) and one longer (2.79 Å) La(2)-C(1) bond length. There is one shorter (2.74 Å) and one longer (2.80 Å) La(2)-C(2) bond length. There is one shorter (2.77 Å) and one longer (2.86 Å) La(2)-C(3) bond length. The La(2)-Cl(2) bond length is 3.27 Å. There is one shorter (2.94 Å) and one longer (3.04 Å) La(2)-Cl(1) bond length. In the third La site, La(3) is bonded in a 8-coordinate geometry to one C(1), two equivalent C(2), two equivalent C(3), one Cl(1), and two equivalent Cl(2) atoms. The La(3)-C(1) bond length is 2.92 Å. There is one shorter (2.44 Å) and one longer (2.69 Å) La(3)-C(2) bond length. There is one shorter (2.72 Å) and one longer (2.80 Å) La(3)-C(3) bond length. The La(3)-Cl(1) bond length is 2.96 Å. There is one shorter (3.01 Å) and one longer (3.31 Å) La(3)-Cl(2) bond length. There are three inequivalent C sites. In the first C site, C(1) is bonded in a 6-coordinate geometry to one La(3), two equivalent La(1), two equivalent La(2), and one C(2) atom. The C(1)-C(2) bond length is 1.36 Å. In the second C site, C(2) is bonded to one La(1), two equivalent La(2), two equivalent La(3), and one C(1) atom to form distorted CLa5C octahedra that share corners with two equivalent C(2)La5C octahedra, corners with four equivalent Cl(2)La5 trigonal bipyramids,  an edgeedge with one C(2)La5C octahedra, and edges with two equivalent Cl(2)La5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 66°. In the third C site, C(3) is bonded in a 6-coordinate geometry to one La(1), two equivalent La(2), two equivalent La(3), and one C(3) atom. The C(3)-C(3) bond length is 1.34 Å. There are two inequivalent Cl sites. In the first Cl site, Cl(1) is bonded in a rectangular see-saw-like geometry to one La(1), one La(3), and two equivalent La(2) atoms. In the second Cl site, Cl(2) is bonded to one La(2), two equivalent La(1), and two equivalent La(3) atoms to form distorted ClLa5 trigonal bipyramids that share corners with four equivalent C(2)La5C octahedra, edges with two equivalent C(2)La5C octahedra, and edges with two equivalent Cl(2)La5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 27-58°.