Materials Data on Si19Te8 by Materials Project
(Si)3(Si2Te)8 crystallizes in the trigonal R3c space group. The structure is zero-dimensional and consists of eighteen silicone molecules and six Si2Te clusters. In each Si2Te cluster, there are six inequivalent Si+0.63+ sites. In the first Si+0.63+ site, Si+0.63+ is bonded in a linear geometry to two Te+1.50- atoms. There are one shorter (2.77 Å) and one longer (3.07 Å) Si–Te bond lengths. In the second Si+0.63+ site, Si+0.63+ is bonded in a linear geometry to two Te+1.50- atoms. There are one shorter (2.64 Å) and one longer (3.10 Å) Si–Te bond lengths. In the third Si+0.63+ site, Si+0.63+ is bonded in a single-bond geometry to one Te+1.50- atom. The Si–Te bond length is 2.62 Å. In the fourth Si+0.63+ site, Si+0.63+ is bonded in a single-bond geometry to one Te+1.50- atom. The Si–Te bond length is 2.63 Å. In the fifth Si+0.63+ site, Si+0.63+ is bonded in a single-bond geometry to one Te+1.50- atom. The Si–Te bond length is 2.70 Å. In the sixth Si+0.63+ site, Si+0.63+ is bonded in a linear geometry to two Te+1.50- atoms. There are one shorter (2.64 Å) and one longer (3.10 Å) Si–Te bond lengths. There are four inequivalent Te+1.50- sites. In the first Te+1.50- site, Te+1.50- is bonded to four Si+0.63+ atoms to form distorted corner-sharing TeSi4 tetrahedra. In the second Te+1.50- site, Te+1.50- is bonded in a trigonal non-coplanar geometry to three Si+0.63+ atoms. In the third Te+1.50- site, Te+1.50- is bonded in a distorted bent 120 degrees geometry to two Si+0.63+ atoms. In the fourth Te+1.50- site, Te+1.50- is bonded to four Si+0.63+ atoms to form distorted corner-sharing TeSi4 tetrahedra.