Materials Data on Li4Mg by Materials Project
Li4Mg crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are six inequivalent Li sites. In the first Li site, Li is bonded to nine Li and three equivalent Mg atoms to form distorted LiLi9Mg3 cuboctahedra that share corners with twelve LiLi9Mg3 cuboctahedra, edges with six equivalent MgLi6Mg6 cuboctahedra, edges with eighteen LiLi9Mg3 cuboctahedra, faces with six equivalent MgLi6Mg6 cuboctahedra, and faces with twelve LiLi9Mg3 cuboctahedra. There are three shorter (3.04 Å) and six longer (3.11 Å) Li–Li bond lengths. All Li–Mg bond lengths are 3.07 Å. In the second Li site, Li is bonded to twelve Li atoms to form LiLi12 cuboctahedra that share corners with three equivalent MgLi6Mg6 cuboctahedra, corners with nine LiLi9Mg3 cuboctahedra, edges with three equivalent MgLi6Mg6 cuboctahedra, edges with twenty-one LiLi9Mg3 cuboctahedra, and faces with eighteen LiLi9Mg3 cuboctahedra. There are three shorter (3.05 Å) and six longer (3.11 Å) Li–Li bond lengths. In the third Li site, Li is bonded to twelve Li atoms to form LiLi12 cuboctahedra that share corners with three equivalent MgLi6Mg6 cuboctahedra, corners with nine LiLi9Mg3 cuboctahedra, edges with three equivalent MgLi6Mg6 cuboctahedra, edges with twenty-one LiLi9Mg3 cuboctahedra, and faces with eighteen LiLi9Mg3 cuboctahedra. There are three shorter (3.04 Å) and six longer (3.11 Å) Li–Li bond lengths. In the fourth Li site, Li is bonded to twelve Li atoms to form LiLi12 cuboctahedra that share corners with three equivalent MgLi6Mg6 cuboctahedra, corners with nine LiLi9Mg3 cuboctahedra, edges with three equivalent MgLi6Mg6 cuboctahedra, edges with twenty-one LiLi9Mg3 cuboctahedra, and faces with eighteen LiLi9Mg3 cuboctahedra. There are a spread of Li–Li bond distances ranging from 3.04–3.11 Å. In the fifth Li site, Li is bonded to twelve Li atoms to form LiLi12 cuboctahedra that share corners with three equivalent MgLi6Mg6 cuboctahedra, corners with nine LiLi9Mg3 cuboctahedra, edges with three equivalent MgLi6Mg6 cuboctahedra, edges with twenty-one LiLi9Mg3 cuboctahedra, and faces with eighteen LiLi9Mg3 cuboctahedra. There are three shorter (3.04 Å) and six longer (3.11 Å) Li–Li bond lengths. In the sixth Li site, Li is bonded to twelve Li atoms to form LiLi12 cuboctahedra that share corners with three equivalent MgLi6Mg6 cuboctahedra, corners with nine LiLi9Mg3 cuboctahedra, edges with three equivalent MgLi6Mg6 cuboctahedra, edges with twenty-one LiLi9Mg3 cuboctahedra, and faces with eighteen LiLi9Mg3 cuboctahedra. There are a spread of Li–Li bond distances ranging from 3.04–3.11 Å. Mg is bonded to six equivalent Li and six equivalent Mg atoms to form distorted MgLi6Mg6 cuboctahedra that share corners with six LiLi12 cuboctahedra, corners with six equivalent MgLi6Mg6 cuboctahedra, edges with six equivalent MgLi6Mg6 cuboctahedra, edges with eighteen LiLi9Mg3 cuboctahedra, faces with six equivalent MgLi6Mg6 cuboctahedra, and faces with twelve equivalent LiLi9Mg3 cuboctahedra. All Mg–Mg bond lengths are 3.11 Å.