Materials Data on Li15Si4 by Materials Project
Li15Si4 crystallizes in the cubic I-43d space group. The structure is three-dimensional. there are two inequivalent Li sites. In the first Li site, Li is bonded in a 3-coordinate geometry to two equivalent Li and three equivalent Si atoms. There are one shorter (2.73 Å) and one longer (2.79 Å) Li–Li bond lengths. There are a spread of Li–Si bond distances ranging from 2.61–2.81 Å. In the second Li site, Li is bonded to eight equivalent Li and four equivalent Si atoms to form LiLi8Si4 cuboctahedra that share corners with eight equivalent SiLi12 cuboctahedra, edges with eight equivalent LiLi8Si4 cuboctahedra, and faces with four equivalent SiLi12 cuboctahedra. All Li–Si bond lengths are 2.86 Å. Si is bonded to twelve Li atoms to form distorted SiLi12 cuboctahedra that share corners with six equivalent LiLi8Si4 cuboctahedra, edges with six equivalent SiLi12 cuboctahedra, faces with three equivalent LiLi8Si4 cuboctahedra, and faces with five equivalent SiLi12 cuboctahedra.