Materials Data on K4Sn20Hg3 by Materials Project
K4Hg3Sn20 crystallizes in the cubic Pm-3n space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded in a distorted body-centered cubic geometry to eight equivalent Sn atoms. All K–Sn bond lengths are 3.94 Å. In the second K site, K is bonded in a 8-coordinate geometry to eight equivalent Sn atoms. All K–Sn bond lengths are 4.18 Å. Hg is bonded to four equivalent Sn atoms to form HgSn4 tetrahedra that share corners with four equivalent SnK2Sn3Hg tetrahedra. All Hg–Sn bond lengths are 2.89 Å. There are two inequivalent Sn sites. In the first Sn site, Sn is bonded in a distorted pentagonal planar geometry to one K and four Sn atoms. There are three shorter (2.89 Å) and one longer (2.91 Å) Sn–Sn bond lengths. In the second Sn site, Sn is bonded to two equivalent K, one Hg, and three Sn atoms to form distorted SnK2Sn3Hg tetrahedra that share a cornercorner with one HgSn4 tetrahedra, corners with fourteen equivalent SnK2Sn3Hg tetrahedra, edges with two equivalent SnK2Sn3Hg tetrahedra, and a faceface with one SnK2Sn3Hg tetrahedra. The Sn–Sn bond length is 2.91 Å.