Materials Data on LiMg2 by Materials Project

Abstract

LiMg2 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are two inequivalent Li sites. In the first Li site, Li is bonded to four Li and eight Mg atoms to form distorted LiLi4Mg8 cuboctahedra that share corners with six equivalent MgLi4Mg8 cuboctahedra, corners with twelve LiLi4Mg8 cuboctahedra, edges with three equivalent LiLi4Mg8 cuboctahedra, edges with fifteen MgLi3Mg9 cuboctahedra, faces with five LiLi4Mg8 cuboctahedra, and faces with fifteen MgLi3Mg9 cuboctahedra. There are two shorter (3.14 Å) and two longer (3.19 Å) Li–Li bond lengths. There are a spread of Li–Mg bond distances ranging from 3.09–3.15 Å. In the second Li site, Li is bonded to four Li and eight Mg atoms to form distorted LiLi4Mg8 cuboctahedra that share corners with six equivalent MgLi4Mg8 cuboctahedra, corners with twelve LiLi4Mg8 cuboctahedra, edges with three equivalent LiLi4Mg8 cuboctahedra, edges with fifteen MgLi3Mg9 cuboctahedra, faces with five LiLi4Mg8 cuboctahedra, and faces with fifteen MgLi3Mg9 cuboctahedra. Both Li–Li bond lengths are 3.19 Å. There are a spread of Li–Mg bond distances ranging from 3.09–3.13 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded to three Li and nine Mg atoms to form distorted MgLi3Mg9 cuboctahedra that share corners with eighteen MgLi3Mg9 cuboctahedra, edges with eight MgLi5Mg7 cuboctahedra, edges with ten LiLi4Mg8 cuboctahedra, faces with seven LiLi4Mg8 cuboctahedra, and faces with thirteen MgLi3Mg9 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.09–3.19 Å. In the second Mg site, Mg is bonded to five Li and seven Mg atoms to form distorted MgLi5Mg7 cuboctahedra that share corners with eighteen MgLi3Mg9 cuboctahedra, edges with eight LiLi4Mg8 cuboctahedra, edges with ten MgLi3Mg9 cuboctahedra, faces with eight LiLi4Mg8 cuboctahedra, and faces with twelve MgLi3Mg9 cuboctahedra. There are three shorter (3.13 Å) and two longer (3.19 Å) Mg–Mg bond lengths. In the third Mg site, Mg is bonded to four Li and eight Mg atoms to form distorted MgLi4Mg8 cuboctahedra that share corners with eighteen MgLi3Mg9 cuboctahedra, edges with six LiLi4Mg8 cuboctahedra, edges with twelve MgLi3Mg9 cuboctahedra, faces with nine LiLi4Mg8 cuboctahedra, and faces with eleven MgLi3Mg9 cuboctahedra. There are two shorter (3.14 Å) and two longer (3.19 Å) Mg–Mg bond lengths. In the fourth Mg site, Mg is bonded to four Li and eight Mg atoms to form distorted MgLi4Mg8 cuboctahedra that share corners with six equivalent MgLi4Mg8 cuboctahedra, corners with twelve LiLi4Mg8 cuboctahedra, edges with six LiLi4Mg8 cuboctahedra, edges with twelve MgLi3Mg9 cuboctahedra, faces with six LiLi4Mg8 cuboctahedra, and faces with fourteen MgLi3Mg9 cuboctahedra. Both Mg–Mg bond lengths are 3.19 Å.