Ce5Si4 crystallizes in the tetragonal P4_12_12 space group. There are three inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to two equivalent Si(1) and four equivalent Si(2) atoms to form corner-sharing CeSi6 octahedra. The corner-sharing octahedral tilt angles are 57°. In the second Ce site, Ce(2) is bonded in a 6-coordinate geometry to three equivalent Si(2) and four equivalent Si(1) atoms. In the third Ce site, Ce(3) is bonded in a 6-coordinate geometry to three equivalent Si(1) and three equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Ce(1), three equivalent Ce(3), four equivalent Ce(2), and one Si(2) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Ce(1), three equivalent Ce(2), three equivalent Ce(3), and one Si(1) atom.
Ce5Si4 crystallizes in the tetragonal P4_12_12 space group. There are three inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to two equivalent Si(1) and four equivalent Si(2) atoms to form corner-sharing CeSi6 octahedra. The corner-sharing octahedral tilt angles are 57°. Both Ce(1)-Si(1) bond lengths are 3.15 Å. There are two shorter (3.08 Å) and two longer (3.14 Å) Ce(1)-Si(2) bond lengths. In the second Ce site, Ce(2) is bonded in a 6-coordinate geometry to three equivalent Si(2) and four equivalent Si(1) atoms. There are a spread of Ce(2)-Si(2) bond distances ranging from 3.09-3.31 Å. There are a spread of Ce(2)-Si(1) bond distances ranging from 3.11-3.79 Å. In the third Ce site, Ce(3) is bonded in a 6-coordinate geometry to three equivalent Si(1) and three equivalent Si(2) atoms. There are a spread of Ce(3)-Si(1) bond distances ranging from 2.92-3.04 Å. There are a spread of Ce(3)-Si(2) bond distances ranging from 2.99-3.03 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Ce(1), three equivalent Ce(3), four equivalent Ce(2), and one Si(2) atom. The Si(1)-Si(2) bond length is 2.52 Å. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Ce(1), three equivalent Ce(2), three equivalent Ce(3), and one Si(1) atom.