Ce5Si3 crystallizes in the tetragonal I4/mcm space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 5-coordinate geometry to two equivalent Si(2) and three equivalent Si(1) atoms. In the second Ce site, Ce(2) is bonded to two equivalent Si(2) and four equivalent Si(1) atoms to form corner-sharing CeSi6 octahedra. The corner-sharing octahedral tilt angles range from 0-58°. There are two inequivalent Si sites. In the first Si site, Si(2) is bonded in a distorted q6 geometry to two equivalent Ce(2) and eight equivalent Ce(1) atoms. In the second Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Ce(2), six equivalent Ce(1), and one Si(1) atom.
Ce5Si3 crystallizes in the tetragonal I4/mcm space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 5-coordinate geometry to two equivalent Si(2) and three equivalent Si(1) atoms. Both Ce(1)-Si(2) bond lengths are 3.14 Å. There is one shorter (3.03 Å) and two longer (3.09 Å) Ce(1)-Si(1) bond lengths. In the second Ce site, Ce(2) is bonded to two equivalent Si(2) and four equivalent Si(1) atoms to form corner-sharing CeSi6 octahedra. The corner-sharing octahedral tilt angles range from 0-58°. Both Ce(2)-Si(2) bond lengths are 3.25 Å. All Ce(2)-Si(1) bond lengths are 3.17 Å. There are two inequivalent Si sites. In the first Si site, Si(2) is bonded in a distorted q6 geometry to two equivalent Ce(2) and eight equivalent Ce(1) atoms. In the second Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Ce(2), six equivalent Ce(1), and one Si(1) atom. The Si(1)-Si(1) bond length is 2.48 Å.