Materials Data on K8SnSb4 by Materials Project
K8SnSb4 crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to six equivalent Sb3- atoms to form distorted KSb6 octahedra that share corners with eighteen equivalent KSb4 tetrahedra, edges with six equivalent KSb6 octahedra, faces with two equivalent SnSb4 tetrahedra, and faces with six equivalent KSb4 tetrahedra. All K–Sb bond lengths are 3.80 Å. In the second K1+ site, K1+ is bonded to four equivalent Sb3- atoms to form distorted KSb4 tetrahedra that share corners with six equivalent KSb6 octahedra, corners with two equivalent SnSb4 tetrahedra, corners with twelve equivalent KSb4 tetrahedra, an edgeedge with one SnSb4 tetrahedra, edges with four equivalent KSb4 tetrahedra, and faces with two equivalent KSb6 octahedra. The corner-sharing octahedra tilt angles range from 33–51°. There are two shorter (3.68 Å) and two longer (3.69 Å) K–Sb bond lengths. Sn4+ is bonded to four equivalent Sb3- atoms to form SnSb4 tetrahedra that share corners with twelve equivalent KSb4 tetrahedra, edges with six equivalent KSb4 tetrahedra, and faces with four equivalent KSb6 octahedra. All Sn–Sb bond lengths are 2.95 Å. Sb3- is bonded in a 10-coordinate geometry to nine K1+ and one Sn4+ atom.