Ce2Ni17Si5 crystallizes in the tetragonal I-4m2 space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 18-coordinate geometry to eight equivalent Ni(1), eight equivalent Ni(2), and two equivalent Si(2) atoms. In the second Ce site, Ce(2) is bonded in a 22-coordinate geometry to two equivalent Ni(3), eight equivalent Ni(1), eight equivalent Ni(2), and four equivalent Si(1) atoms. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 12-coordinate geometry to one Ce(1), one Ce(2), one Ni(3), three equivalent Ni(1), four equivalent Ni(2), and two equivalent Si(1) atoms. In the second Ni site, Ni(2) is bonded to one Ce(1), one Ce(2), three equivalent Ni(2), four equivalent Ni(1), one Si(2), and two equivalent Si(1) atoms to form a mixture of distorted edge, face, and corner-sharing NiCe2Si3Ni7 cuboctahedra. In the third Ni site, Ni(3) is bonded in a 14-coordinate geometry to two equivalent Ce(2), eight equivalent Ni(1), and four equivalent Si(1) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Ce(2), one Ni(3), four equivalent Ni(1), four equivalent Ni(2), and one Si(2) atom. In the second Si site, Si(2) is bonded in a 14-coordinate geometry to two equivalent Ce(1), eight equivalent Ni(2), and four equivalent Si(1) atoms.
Ce2Ni17Si5 crystallizes in the tetragonal I-4m2 space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 18-coordinate geometry to eight equivalent Ni(1), eight equivalent Ni(2), and two equivalent Si(2) atoms. All Ce(1)-Ni(1) bond lengths are 3.17 Å. All Ce(1)-Ni(2) bond lengths are 3.01 Å. Both Ce(1)-Si(2) bond lengths are 3.10 Å. In the second Ce site, Ce(2) is bonded in a 22-coordinate geometry to two equivalent Ni(3), eight equivalent Ni(1), eight equivalent Ni(2), and four equivalent Si(1) atoms. Both Ce(2)-Ni(3) bond lengths are 3.10 Å. All Ce(2)-Ni(1) bond lengths are 3.02 Å. All Ce(2)-Ni(2) bond lengths are 3.25 Å. All Ce(2)-Si(1) bond lengths are 3.29 Å. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 12-coordinate geometry to one Ce(1), one Ce(2), one Ni(3), three equivalent Ni(1), four equivalent Ni(2), and two equivalent Si(1) atoms. The Ni(1)-Ni(3) bond length is 2.64 Å. There are a spread of Ni(1)-Ni(1) bond distances ranging from 2.44-2.64 Å. There are a spread of Ni(1)-Ni(2) bond distances ranging from 2.44-2.61 Å. There is one shorter (2.32 Å) and one longer (2.33 Å) Ni(1)-Si(1) bond length. In the second Ni site, Ni(2) is bonded to one Ce(1), one Ce(2), three equivalent Ni(2), four equivalent Ni(1), one Si(2), and two equivalent Si(1) atoms to form a mixture of distorted edge, face, and corner-sharing NiCe2Si3Ni7 cuboctahedra. There are a spread of Ni(2)-Ni(2) bond distances ranging from 2.42-2.65 Å. The Ni(2)-Si(2) bond length is 2.54 Å. There is one shorter (2.37 Å) and one longer (2.40 Å) Ni(2)-Si(1) bond length. In the third Ni site, Ni(3) is bonded in a 14-coordinate geometry to two equivalent Ce(2), eight equivalent Ni(1), and four equivalent Si(1) atoms. All Ni(3)-Si(1) bond lengths are 2.43 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Ce(2), one Ni(3), four equivalent Ni(1), four equivalent Ni(2), and one Si(2) atom. The Si(1)-Si(2) bond length is 2.72 Å. In the second Si site, Si(2) is bonded in a 14-coordinate geometry to two equivalent Ce(1), eight equivalent Ni(2), and four equivalent Si(1) atoms.