Materials Data on CeMg2Ni9 by Materials Project

CeMg2Ni9 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Mg is bonded in a 12-coordinate geometry to twelve Ni atoms. There are a spread of Mg–Ni bond distances ranging from 2.80–2.84 Å. Ce is bonded in a distorted hexagonal planar geometry to eighteen Ni atoms. There are six shorter (2.80 Å) and twelve longer (3.15 Å) Ce–Ni bond lengths. There are three inequivalent Ni sites. In the first Ni site, Ni is bonded to three equivalent Mg, two equivalent Ce, and seven Ni atoms to form NiCe2Mg3Ni7 cuboctahedra that share corners with seventeen NiMg6Ni6 cuboctahedra, edges with eight equivalent NiCe2Mg3Ni7 cuboctahedra, and faces with fourteen NiCe2Mg3Ni7 cuboctahedra. There are a spread of Ni–Ni bond distances ranging from 2.39–2.46 Å. In the second Ni site, Ni is bonded in a 12-coordinate geometry to three equivalent Ce and nine Ni atoms. All Ni–Ni bond lengths are 2.80 Å. In the third Ni site, Ni is bonded to six equivalent Mg and six equivalent Ni atoms to form NiMg6Ni6 cuboctahedra that share corners with twelve equivalent NiCe2Mg3Ni7 cuboctahedra, edges with six equivalent NiMg6Ni6 cuboctahedra, and faces with eighteen equivalent NiCe2Mg3Ni7 cuboctahedra.