Materials Data on LiMg2 by Materials Project

Abstract

LiMg2 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Li is bonded to nine equivalent Li and three equivalent Mg atoms to form distorted LiLi9Mg3 cuboctahedra that share corners with six equivalent LiLi9Mg3 cuboctahedra, corners with twelve MgMg12 cuboctahedra, edges with six equivalent MgLi3Mg9 cuboctahedra, edges with twelve equivalent LiLi9Mg3 cuboctahedra, faces with eight MgMg12 cuboctahedra, and faces with twelve equivalent LiLi9Mg3 cuboctahedra. There are three shorter (3.09 Å) and six longer (3.20 Å) Li–Li bond lengths. All Li–Mg bond lengths are 3.09 Å. There are three inequivalent Mg sites. In the first Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with six equivalent LiLi9Mg3 cuboctahedra, corners with twelve MgMg12 cuboctahedra, edges with eighteen MgMg12 cuboctahedra, a faceface with one LiLi9Mg3 cuboctahedra, and faces with nineteen MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.11–3.20 Å. In the second Mg site, Mg is bonded to three equivalent Li and nine Mg atoms to form distorted MgLi3Mg9 cuboctahedra that share corners with six equivalent LiLi9Mg3 cuboctahedra, corners with twelve MgLi3Mg9 cuboctahedra, edges with six equivalent LiLi9Mg3 cuboctahedra, edges with twelve MgMg12 cuboctahedra, faces with seven equivalent LiLi9Mg3 cuboctahedra, and faces with thirteen MgMg12 cuboctahedra. All Mg–Mg bond lengths are 3.20 Å. In the third Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with six equivalent LiLi9Mg3 cuboctahedra, corners with twelve MgLi3Mg9 cuboctahedra, edges with eighteen MgMg12 cuboctahedra, a faceface with one LiLi9Mg3 cuboctahedra, and faces with nineteen MgMg12 cuboctahedra. There are three shorter (3.11 Å) and six longer (3.20 Å) Mg–Mg bond lengths.