Materials Data on LiMg2 by Materials Project

LiMg2 crystallizes in the orthorhombic Amm2 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 MgLi4Mg8 cuboctahedra, faces with six LiLi4Mg8 cuboctahedra, and faces with fourteen MgLi2Mg10 cuboctahedra. There are two shorter (3.15 Å) and two longer (3.18 Å) Li–Li bond lengths. There are six shorter (3.10 Å) and two longer (3.18 Å) Li–Mg bond lengths. 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 MgLi2Mg10 cuboctahedra, faces with six LiLi4Mg8 cuboctahedra, and faces with fourteen MgLi2Mg10 cuboctahedra. Both Li–Li bond lengths are 3.15 Å. There are six shorter (3.10 Å) and two longer (3.19 Å) Li–Mg bond lengths. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded to two equivalent Li and ten Mg atoms to form distorted MgLi2Mg10 cuboctahedra that share corners with eighteen MgLi2Mg10 cuboctahedra, edges with eight equivalent LiLi4Mg8 cuboctahedra, edges with ten MgLi4Mg8 cuboctahedra, faces with eight LiLi4Mg8 cuboctahedra, and faces with twelve MgLi2Mg10 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.11–3.22 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 MgLi2Mg10 cuboctahedra, edges with six MgLi2Mg10 cuboctahedra, edges with twelve LiLi4Mg8 cuboctahedra, faces with six LiLi4Mg8 cuboctahedra, and faces with fourteen MgLi2Mg10 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.12–3.16 Å. In the third Mg site, Mg is bonded to six Li and six Mg atoms to form distorted MgLi6Mg6 cuboctahedra that share corners with eighteen MgLi2Mg10 cuboctahedra, edges with four equivalent LiLi4Mg8 cuboctahedra, edges with fourteen MgLi2Mg10 cuboctahedra, faces with ten LiLi4Mg8 cuboctahedra, and faces with ten MgLi2Mg10 cuboctahedra. Both Mg–Mg bond lengths are 3.15 Å. In the fourth Mg site, Mg is bonded to four Li and eight Mg atoms to form MgLi4Mg8 cuboctahedra that share corners with six equivalent MgLi4Mg8 cuboctahedra, corners with twelve LiLi4Mg8 cuboctahedra, edges with six LiLi4Mg8 cuboctahedra, edges with twelve MgLi2Mg10 cuboctahedra, faces with four LiLi4Mg8 cuboctahedra, and faces with sixteen MgLi2Mg10 cuboctahedra. Both Mg–Mg bond lengths are 3.15 Å.