Materials Data on Sr2TlI5 by Materials Project
Sr2TlI5 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 8-coordinate geometry to eight I1- atoms. There are a spread of Sr–I bond distances ranging from 3.40–3.66 Å. In the second Sr2+ site, Sr2+ is bonded to seven I1- atoms to form distorted edge-sharing SrI7 pentagonal bipyramids. There are a spread of Sr–I bond distances ranging from 3.25–3.47 Å. Tl1+ is bonded in a 8-coordinate geometry to eight I1- atoms. There are a spread of Tl–I bond distances ranging from 3.45–4.14 Å. There are five inequivalent I1- sites. In the first I1- site, I1- is bonded to two equivalent Sr2+ and two equivalent Tl1+ atoms to form distorted ISr2Tl2 trigonal pyramids that share corners with six ISr3Tl2 square pyramids, corners with two equivalent ISr2Tl2 trigonal pyramids, edges with three ISr3Tl2 square pyramids, and an edgeedge with one ISr2Tl2 trigonal pyramid. In the second I1- site, I1- is bonded in a 5-coordinate geometry to three Sr2+ and two equivalent Tl1+ atoms. In the third I1- site, I1- is bonded to three Sr2+ and two equivalent Tl1+ atoms to form distorted ISr3Tl2 square pyramids that share corners with eight ISr3Tl2 square pyramids, corners with two equivalent ISr2Tl2 trigonal pyramids, an edgeedge with one ISr3Tl2 square pyramid, edges with two equivalent ISr2Tl2 trigonal pyramids, and a faceface with one ISr3Tl2 square pyramid. In the fourth I1- site, I1- is bonded to three Sr2+ and two equivalent Tl1+ atoms to form distorted ISr3Tl2 square pyramids that share corners with four equivalent ISr3Tl2 square pyramids, corners with four equivalent ISr2Tl2 trigonal pyramids, edges with three ISr3Tl2 square pyramids, an edgeedge with one ISr2Tl2 trigonal pyramid, and a faceface with one ISr3Tl2 square pyramid. In the fifth I1- site, I1- is bonded in a distorted rectangular see-saw-like geometry to four Sr2+ atoms.