Materials Data on Ce2Si2Ni15 by Materials Project

Ce2Ni15Si2 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Ce sites. In the first Ce site, Ce is bonded in a 6-coordinate geometry to eighteen Ni atoms. There are a spread of Ce–Ni bond distances ranging from 2.89–3.26 Å. In the second Ce site, Ce is bonded in a 8-coordinate geometry to eighteen Ni and two equivalent Si atoms. There are a spread of Ce–Ni bond distances ranging from 2.94–3.16 Å. Both Ce–Si bond lengths are 2.92 Å. There are three inequivalent Ni sites. In the first Ni site, Ni is bonded to two equivalent Ce, eight Ni, and two equivalent Si atoms to form NiCe2Si2Ni8 cuboctahedra that share corners with fourteen NiCe2Si2Ni8 cuboctahedra, edges with six equivalent NiCe3SiNi8 cuboctahedra, and faces with ten NiCe2Si2Ni8 cuboctahedra. There are four shorter (2.39 Å) and four longer (2.44 Å) Ni–Ni bond lengths. Both Ni–Si bond lengths are 2.54 Å. In the second Ni site, Ni is bonded in a 12-coordinate geometry to two Ce, eight Ni, and two equivalent Si atoms. There are a spread of Ni–Ni bond distances ranging from 2.44–2.55 Å. Both Ni–Si bond lengths are 2.77 Å. In the third Ni site, Ni is bonded to three Ce, eight Ni, and one Si atom to form a mixture of edge, corner, and face-sharing NiCe3SiNi8 cuboctahedra. Both Ni–Ni bond lengths are 2.42 Å. The Ni–Si bond length is 2.58 Å. Si is bonded in a 2-coordinate geometry to one Ce, twelve Ni, and one Si atom. The Si–Si bond length is 2.41 Å.