Materials Data on LiMg2 by Materials Project

Abstract

LiMg2 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Li is bonded to six equivalent Li and six Mg atoms to form distorted LiLi6Mg6 cuboctahedra that share corners with six equivalent LiLi6Mg6 cuboctahedra, corners with twelve MgLi4Mg8 cuboctahedra, edges with four equivalent LiLi6Mg6 cuboctahedra, edges with fourteen MgLi4Mg8 cuboctahedra, faces with eight equivalent LiLi6Mg6 cuboctahedra, and faces with twelve MgLi4Mg8 cuboctahedra. There are two shorter (3.10 Å) and four longer (3.15 Å) Li–Li bond lengths. There are four shorter (3.12 Å) and two longer (3.14 Å) Li–Mg bond lengths. There are two inequivalent Mg sites. In the first Mg site, Mg is bonded to four equivalent Li and eight Mg atoms to form distorted MgLi4Mg8 cuboctahedra that share corners with six equivalent LiLi6Mg6 cuboctahedra, corners with twelve MgLi4Mg8 cuboctahedra, edges with three equivalent LiLi6Mg6 cuboctahedra, edges with fifteen MgLi4Mg8 cuboctahedra, faces with eight equivalent LiLi6Mg6 cuboctahedra, and faces with twelve MgLi4Mg8 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.10–3.21 Å. In the second Mg site, Mg is bonded to two equivalent Li and ten Mg atoms to form distorted MgLi2Mg10 cuboctahedra that share corners with six equivalent LiLi6Mg6 cuboctahedra, corners with twelve MgLi4Mg8 cuboctahedra, edges with seven equivalent MgLi4Mg8 cuboctahedra, edges with eleven equivalent LiLi6Mg6 cuboctahedra, faces with four equivalent LiLi6Mg6 cuboctahedra, and faces with sixteen MgLi4Mg8 cuboctahedra. There are two shorter (3.10 Å) and two longer (3.18 Å) Mg–Mg bond lengths.