Materials Data on LiMg2 by Materials Project

Abstract

LiMg2 crystallizes in the trigonal R32 space group. The structure is three-dimensional. Li is bonded to three equivalent Li and nine Mg atoms to form distorted LiLi3Mg9 cuboctahedra that share corners with six equivalent MgLi6Mg6 cuboctahedra, corners with twelve equivalent LiLi3Mg9 cuboctahedra, edges with six equivalent LiLi3Mg9 cuboctahedra, edges with twelve equivalent MgLi4Mg8 cuboctahedra, faces with four equivalent LiLi3Mg9 cuboctahedra, and faces with sixteen MgLi6Mg6 cuboctahedra. All Li–Li bond lengths are 3.18 Å. There are a spread of Li–Mg bond distances ranging from 3.08–3.18 Å. There are two inequivalent Mg sites. In the first Mg site, Mg is bonded to six equivalent Li and six equivalent Mg atoms to form MgLi6Mg6 cuboctahedra that share corners with six equivalent MgLi6Mg6 cuboctahedra, corners with twelve equivalent LiLi3Mg9 cuboctahedra, edges with eighteen MgLi6Mg6 cuboctahedra, faces with eight equivalent LiLi3Mg9 cuboctahedra, and faces with twelve equivalent MgLi4Mg8 cuboctahedra. All Mg–Mg bond lengths are 3.09 Å. In the second Mg site, Mg is bonded to four equivalent Li and eight Mg atoms to form distorted MgLi4Mg8 cuboctahedra that share corners with eighteen equivalent MgLi4Mg8 cuboctahedra, edges with eight equivalent LiLi3Mg9 cuboctahedra, edges with ten MgLi6Mg6 cuboctahedra, faces with eight equivalent LiLi3Mg9 cuboctahedra, and faces with twelve MgLi6Mg6 cuboctahedra. There are two shorter (3.16 Å) and four longer (3.19 Å) Mg–Mg bond lengths.