Li8Al3Si5 crystallizes in the cubic P-43m space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to three equivalent Al(1) and one Si(2) atom to form distorted corner-sharing LiAl3Si tetrahedra. In the second Li site, Li(2) is bonded to four equivalent Si(1) atoms to form distorted corner-sharing LiSi4 tetrahedra. In the third Li site, Li(3) is bonded to four equivalent Si(1) atoms to form distorted corner-sharing LiSi4 tetrahedra. Al(1) is bonded in a distorted body-centered cubic geometry to four equivalent Li(1) and four equivalent Si(1) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 7-coordinate geometry to one Li(2), three equivalent Li(3), and three equivalent Al(1) atoms. In the second Si site, Si(2) is bonded in a distorted tetrahedral geometry to four equivalent Li(1) atoms.
Li8Al3Si5 crystallizes in the cubic P-43m space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to three equivalent Al(1) and one Si(2) atom to form distorted corner-sharing LiAl3Si tetrahedra. All Li(1)-Al(1) bond lengths are 2.72 Å. The Li(1)-Si(2) bond length is 2.67 Å. In the second Li site, Li(2) is bonded to four equivalent Si(1) atoms to form distorted corner-sharing LiSi4 tetrahedra. All Li(2)-Si(1) bond lengths are 2.68 Å. In the third Li site, Li(3) is bonded to four equivalent Si(1) atoms to form distorted corner-sharing LiSi4 tetrahedra. All Li(3)-Si(1) bond lengths are 2.72 Å. Al(1) is bonded in a distorted body-centered cubic geometry to four equivalent Li(1) and four equivalent Si(1) atoms. All Al(1)-Si(1) bond lengths are 2.70 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 7-coordinate geometry to one Li(2), three equivalent Li(3), and three equivalent Al(1) atoms. In the second Si site, Si(2) is bonded in a distorted tetrahedral geometry to four equivalent Li(1) atoms.