La4Cu3Sb8 crystallizes in the tetragonal I-42m space group. La(1) is bonded in a 11-coordinate geometry to one Cu(1), two equivalent Cu(2), two equivalent Sb(2), two equivalent Sb(3), and four equivalent Sb(1) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 8-coordinate geometry to four equivalent La(1) and four equivalent Sb(1) atoms. In the second Cu site, Cu(2) is bonded in a 8-coordinate geometry to four equivalent La(1) and four equivalent Sb(1) atoms. There are three inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 7-coordinate geometry to four equivalent La(1), one Cu(1), and two equivalent Cu(2) atoms. In the second Sb site, Sb(2) is bonded in a 8-coordinate geometry to four equivalent La(1) and four equivalent Sb(3) atoms. In the third Sb site, Sb(3) is bonded in a 8-coordinate geometry to four equivalent La(1) and four equivalent Sb(2) atoms.
La4Cu3Sb8 crystallizes in the tetragonal I-42m space group. La(1) is bonded in a 11-coordinate geometry to one Cu(1), two equivalent Cu(2), two equivalent Sb(2), two equivalent Sb(3), and four equivalent Sb(1) atoms. The La(1)-Cu(1) bond length is 3.29 Å. Both La(1)-Cu(2) bond lengths are 3.29 Å. Both La(1)-Sb(2) bond lengths are 3.42 Å. Both La(1)-Sb(3) bond lengths are 3.42 Å. There are two shorter (3.30 Å) and two longer (3.33 Å) La(1)-Sb(1) bond lengths. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 8-coordinate geometry to four equivalent La(1) and four equivalent Sb(1) atoms. All Cu(1)-Sb(1) bond lengths are 2.63 Å. In the second Cu site, Cu(2) is bonded in a 8-coordinate geometry to four equivalent La(1) and four equivalent Sb(1) atoms. All Cu(2)-Sb(1) bond lengths are 2.61 Å. There are three inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 7-coordinate geometry to four equivalent La(1), one Cu(1), and two equivalent Cu(2) atoms. In the second Sb site, Sb(2) is bonded in a 8-coordinate geometry to four equivalent La(1) and four equivalent Sb(3) atoms. All Sb(2)-Sb(3) bond lengths are 3.14 Å. In the third Sb site, Sb(3) is bonded in a 8-coordinate geometry to four equivalent La(1) and four equivalent Sb(2) atoms.