Materials Data on CsSr2I5 by Materials Project

CsSr2I5 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Cs1+ is bonded in a 8-coordinate geometry to eight I1- atoms. There are a spread of Cs–I bond distances ranging from 3.76–4.14 Å. 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 3.41–3.68 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 3.33–3.56 Å. There are five inequivalent I1- sites. In the first I1- site, I1- is bonded to two equivalent Cs1+ and two equivalent Sr2+ atoms to form distorted ICs2Sr2 trigonal pyramids that share corners with four equivalent ICs2Sr3 square pyramids, corners with two equivalent ICs2Sr3 trigonal bipyramids, corners with six ICs2Sr2 trigonal pyramids, an edgeedge with one ICs2Sr3 square pyramid, edges with two equivalent ICs2Sr3 trigonal bipyramids, and an edgeedge with one ICs2Sr2 trigonal pyramid. In the second I1- site, I1- is bonded in a 5-coordinate geometry to two equivalent Cs1+ and three Sr2+ atoms. In the third I1- site, I1- is bonded to two equivalent Cs1+ and three Sr2+ atoms to form distorted ICs2Sr3 trigonal bipyramids that share corners with four equivalent ICs2Sr3 square pyramids, corners with four equivalent ICs2Sr3 trigonal bipyramids, corners with four ICs2Sr2 trigonal pyramids, an edgeedge with one ICs2Sr3 square pyramid, edges with four ISr4 trigonal pyramids, and a faceface with one ICs2Sr3 square pyramid. In the fourth I1- site, I1- is bonded to two equivalent Cs1+ and three Sr2+ atoms to form distorted ICs2Sr3 square pyramids that share corners with four equivalent ICs2Sr3 trigonal bipyramids, corners with eight ICs2Sr2 trigonal pyramids, edges with two equivalent ICs2Sr3 square pyramids, an edgeedge with one ICs2Sr3 trigonal bipyramid, edges with two ICs2Sr2 trigonal pyramids, and a faceface with one ICs2Sr3 trigonal bipyramid. In the fifth I1- site, I1- is bonded to four Sr2+ atoms to form distorted ISr4 trigonal pyramids that share corners with four equivalent ICs2Sr3 square pyramids, corners with two equivalent ICs2Sr3 trigonal bipyramids, corners with six ICs2Sr2 trigonal pyramids, an edgeedge with one ICs2Sr3 square pyramid, edges with two equivalent ICs2Sr3 trigonal bipyramids, and an edgeedge with one ISr4 trigonal pyramid.

碘化铯锶（CsSr2I5）属于单斜晶系（monoclinic）P2₁/c空间群（P2₁/c space group），其晶体结构为三维网状。一价铯离子（Cs1+）以8配位几何构型与8个一价碘离子（I1-）成键，Cs–I键长分布范围为3.76~4.14埃。体系中存在两个不等价的二价锶离子（Sr2+）位点：在第一个Sr2+位点中，Sr2+以8配位几何构型与8个I1-成键，Sr–I键长分布范围为3.41~3.68埃；在第二个Sr2+位点中，Sr2+与7个I1-成键，形成畸变的共边SrI7五角双锥（pentagonal bipyramids）结构，Sr–I键长分布范围为3.33~3.56埃。
体系中存在五个不等价的I1-位点：在第一个I1-位点中，I1-与2个等价的Cs1+及2个等价的Sr2+成键，形成畸变的ICs2Sr2三角锥（trigonal pyramids）结构，该多面体分别与4个等价的ICs2Sr3四方锥（square pyramids）、2个等价的ICs2Sr3三角双锥（trigonal bipyramids）、6个ICs2Sr2三角锥共享顶点，与1个ICs2Sr3四方锥共边，与2个等价的ICs2Sr3三角双锥共边，同时与1个ICs2Sr2三角锥共边。
在第二个I1-位点中，I1-以5配位几何构型与2个等价的Cs1+及3个Sr2+成键。
在第三个I1-位点中，I1-与2个等价的Cs1+及3个Sr2+成键，形成畸变的ICs2Sr3三角双锥结构，该多面体分别与4个等价的ICs2Sr3四方锥、4个等价的ICs2Sr3三角双锥、4个ICs2Sr2三角锥共享顶点，与1个ICs2Sr3四方锥共边，与4个ISr4三角锥共边，同时与1个ICs2Sr3四方锥共面。
在第四个I1-位点中，I1-与2个等价的Cs1+及3个Sr2+成键，形成畸变的ICs2Sr3四方锥结构，该多面体分别与4个等价的ICs2Sr3三角双锥、8个ICs2Sr2三角锥共享顶点，与2个等价的ICs2Sr3四方锥共边，与1个ICs2Sr3三角双锥共边，与2个ICs2Sr2三角锥共边，同时与1个ICs2Sr3三角双锥共面。
在第五个I1-位点中，I1-与4个Sr2+成键，形成畸变的ISr4三角锥结构，该多面体分别与4个等价的ICs2Sr3四方锥、2个等价的ICs2Sr3三角双锥、6个ICs2Sr2三角锥共享顶点，与1个ICs2Sr3四方锥共边，与2个等价的ICs2Sr3三角双锥共边，同时与1个ISr4三角锥共边。