Materials Data on Sn7(SI3)2 by Materials Project
Sn7(SI3)2 crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of one Sn7(SI3)2 sheet oriented in the (2, 0, -1) direction. there are four inequivalent Sn sites. In the first Sn site, Sn is bonded in a 2-coordinate geometry to two equivalent Sn and two I atoms. Both Sn–Sn bond lengths are 3.01 Å. There are one shorter (3.07 Å) and one longer (3.31 Å) Sn–I bond lengths. In the second Sn site, Sn is bonded in a 3-coordinate geometry to three equivalent S atoms. There are one shorter (2.64 Å) and two longer (2.77 Å) Sn–S bond lengths. In the third Sn site, Sn is bonded in a square co-planar geometry to four equivalent Sn atoms. In the fourth Sn site, Sn is bonded to one S and four I atoms to form distorted edge-sharing SnSI4 square pyramids. The Sn–S bond length is 2.68 Å. There are two shorter (3.19 Å) and two longer (3.30 Å) Sn–I bond lengths. S is bonded to four Sn atoms to form a mixture of corner and edge-sharing SSn4 trigonal pyramids. There are three inequivalent I sites. In the first I site, I is bonded in a single-bond geometry to one Sn atom. In the second I site, I is bonded in a trigonal non-coplanar geometry to three Sn atoms. In the third I site, I is bonded in an L-shaped geometry to two equivalent Sn atoms.