Lu5Si3C crystallizes in the hexagonal P6_3/mcm space group. There are two inequivalent Lu sites. In the first Lu site, Lu(1) is bonded in a 6-coordinate geometry to six equivalent Si(1) atoms. In the second Lu site, Lu(2) is bonded in a 2-coordinate geometry to five equivalent Si(1) and two equivalent C(1) atoms. Si(1) is bonded in a 9-coordinate geometry to four equivalent Lu(1) and five equivalent Lu(2) atoms. C(1) is bonded to six equivalent Lu(2) atoms to form face-sharing CLu6 octahedra.
Lu5Si3C crystallizes in the hexagonal P6_3/mcm space group. There are two inequivalent Lu sites. In the first Lu site, Lu(1) is bonded in a 6-coordinate geometry to six equivalent Si(1) atoms. All Lu(1)-Si(1) bond lengths are 2.95 Å. In the second Lu site, Lu(2) is bonded in a 2-coordinate geometry to five equivalent Si(1) and two equivalent C(1) atoms. There are a spread of Lu(2)-Si(1) bond distances ranging from 2.91-3.47 Å. Both Lu(2)-C(1) bond lengths are 2.41 Å. Si(1) is bonded in a 9-coordinate geometry to four equivalent Lu(1) and five equivalent Lu(2) atoms. C(1) is bonded to six equivalent Lu(2) atoms to form face-sharing CLu6 octahedra.