TbLaC4 crystallizes in the monoclinic C2/m space group. Tb(1) is bonded in a 10-coordinate geometry to four equivalent C(1) and six equivalent C(2) atoms. La(1) is bonded in a distorted q4 geometry to four equivalent C(2) and six equivalent C(1) atoms. There are two inequivalent C sites. In the first C site, C(1) is bonded in a 6-coordinate geometry to two equivalent Tb(1), three equivalent La(1), and one C(2) atom. In the second C site, C(2) is bonded in a 6-coordinate geometry to three equivalent Tb(1), two equivalent La(1), and one C(1) atom.
TbLaC4 crystallizes in the monoclinic C2/m space group. Tb(1) is bonded in a 10-coordinate geometry to four equivalent C(1) and six equivalent C(2) atoms. All Tb(1)-C(1) bond lengths are 2.68 Å. There are two shorter (2.47 Å) and four longer (2.75 Å) Tb(1)-C(2) bond lengths. La(1) is bonded in a distorted q4 geometry to four equivalent C(2) and six equivalent C(1) atoms. All La(1)-C(2) bond lengths are 2.84 Å. There are two shorter (2.62 Å) and four longer (2.83 Å) La(1)-C(1) bond lengths. There are two inequivalent C sites. In the first C site, C(1) is bonded in a 6-coordinate geometry to two equivalent Tb(1), three equivalent La(1), and one C(2) atom. The C(1)-C(2) bond length is 1.30 Å. In the second C site, C(2) is bonded in a 6-coordinate geometry to three equivalent Tb(1), two equivalent La(1), and one C(1) atom.