Materials Data on Li2Mg by Materials Project

Abstract

MgLi2 is beta-derived structured and crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. there are three inequivalent Li sites. In the first Li site, Li is bonded to twelve Li atoms to form LiLi12 cuboctahedra that share corners with six equivalent MgLi3Mg9 cuboctahedra, corners with twelve LiLi12 cuboctahedra, edges with eighteen LiLi12 cuboctahedra, a faceface with one MgLi3Mg9 cuboctahedra, and faces with nineteen LiLi12 cuboctahedra. There are a spread of Li–Li bond distances ranging from 3.01–3.16 Å. In the second Li site, Li is bonded to nine Li and three equivalent Mg atoms to form distorted LiLi9Mg3 cuboctahedra that share corners with six equivalent MgLi3Mg9 cuboctahedra, corners with twelve LiLi9Mg3 cuboctahedra, edges with six equivalent MgLi3Mg9 cuboctahedra, edges with twelve LiLi12 cuboctahedra, faces with seven equivalent MgLi3Mg9 cuboctahedra, and faces with thirteen LiLi12 cuboctahedra. All Li–Li bond lengths are 3.16 Å. All Li–Mg bond lengths are 3.05 Å. In the third Li site, Li is bonded to twelve Li atoms to form LiLi12 cuboctahedra that share corners with six equivalent MgLi3Mg9 cuboctahedra, corners with twelve LiLi9Mg3 cuboctahedra, edges with eighteen LiLi12 cuboctahedra, a faceface with one MgLi3Mg9 cuboctahedra, and faces with nineteen LiLi12 cuboctahedra. There are three shorter (3.01 Å) and six longer (3.16 Å) Li–Li bond lengths. Mg is bonded to three equivalent Li and nine equivalent Mg atoms to form distorted MgLi3Mg9 cuboctahedra that share corners with six equivalent MgLi3Mg9 cuboctahedra, corners with twelve LiLi12 cuboctahedra, edges with six equivalent LiLi9Mg3 cuboctahedra, edges with twelve equivalent MgLi3Mg9 cuboctahedra, faces with eight LiLi12 cuboctahedra, and faces with twelve equivalent MgLi3Mg9 cuboctahedra. All Mg–Mg bond lengths are 3.16 Å.