Materials Data on LaMg2Ni9 by Materials Project

Abstract

LaMg2Ni9 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 2.81–2.87 Å. La is bonded in a distorted hexagonal planar geometry to eighteen Ni atoms. There are six shorter (2.83 Å) and twelve longer (3.18 Å) La–Ni bond lengths. There are three inequivalent Ni sites. In the first Ni site, Ni is bonded to three equivalent Mg, two equivalent La, and seven Ni atoms to form NiLa2Mg3Ni7 cuboctahedra that share corners with seventeen NiMg6Ni6 cuboctahedra, edges with eight equivalent NiLa2Mg3Ni7 cuboctahedra, and faces with fourteen NiLa2Mg3Ni7 cuboctahedra. There are a spread of Ni–Ni bond distances ranging from 2.39–2.48 Å. In the second Ni site, Ni is bonded in a 12-coordinate geometry to three equivalent La and nine Ni atoms. All Ni–Ni bond lengths are 2.83 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 NiLa2Mg3Ni7 cuboctahedra, edges with six equivalent NiMg6Ni6 cuboctahedra, and faces with eighteen equivalent NiLa2Mg3Ni7 cuboctahedra.