Materials Data on Ce2Si9Ni17 by Materials Project
Ce2Ni17Si9 crystallizes in the orthorhombic Fmmm space group. The structure is three-dimensional. Ce3+ is bonded in a 8-coordinate geometry to eight Si4- atoms. There are four shorter (3.18 Å) and four longer (3.31 Å) Ce–Si bond lengths. There are five inequivalent Ni+1.76+ sites. In the first Ni+1.76+ site, Ni+1.76+ is bonded in a 5-coordinate geometry to five Si4- atoms. There are a spread of Ni–Si bond distances ranging from 2.27–2.49 Å. In the second Ni+1.76+ site, Ni+1.76+ is bonded in a 4-coordinate geometry to four Si4- atoms. There are two shorter (2.44 Å) and two longer (2.51 Å) Ni–Si bond lengths. In the third Ni+1.76+ site, Ni+1.76+ is bonded to four Si4- atoms to form distorted NiSi4 tetrahedra that share corners with two equivalent SiSi4Ni8 cuboctahedra and edges with two equivalent NiSi4 tetrahedra. There are two shorter (2.29 Å) and two longer (2.49 Å) Ni–Si bond lengths. In the fourth Ni+1.76+ site, Ni+1.76+ is bonded in a 5-coordinate geometry to five Si4- atoms. There are a spread of Ni–Si bond distances ranging from 2.30–2.56 Å. In the fifth Ni+1.76+ site, Ni+1.76+ is bonded in a distorted rectangular see-saw-like geometry to four equivalent Si4- atoms. All Ni–Si bond lengths are 2.30 Å. There are three inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 12-coordinate geometry to two equivalent Ce3+, eight Ni+1.76+, and one Si4- atom. The Si–Si bond length is 2.46 Å. In the second Si4- site, Si4- is bonded in a 12-coordinate geometry to two equivalent Ce3+, nine Ni+1.76+, and one Si4- atom. The Si–Si bond length is 2.67 Å. In the third Si4- site, Si4- is bonded to eight Ni+1.76+ and four equivalent Si4- atoms to form SiSi4Ni8 cuboctahedra that share corners with eight equivalent NiSi4 tetrahedra.