Materials Data on Sr2CaI6 by Materials Project

Abstract

Sr2CaI6 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 3.38–3.92 Å. In the second 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 3.39–3.73 Å. Ca2+ is bonded to six I1- atoms to form edge-sharing CaI6 octahedra. There are a spread of Ca–I bond distances ranging from 3.04–3.19 Å. There are six inequivalent I1- sites. In the first I1- site, I1- is bonded in a 4-coordinate geometry to two Sr2+ and two equivalent Ca2+ atoms. In the second I1- site, I1- is bonded to three Sr2+ and one Ca2+ atom to form distorted ISr3Ca trigonal pyramids that share corners with four ISr3Ca trigonal pyramids and edges with two equivalent ISr4 trigonal pyramids. In the third I1- site, I1- is bonded to four Sr2+ atoms to form a mixture of distorted edge and corner-sharing ISr4 trigonal pyramids. In the fourth I1- site, I1- is bonded in a distorted trigonal planar geometry to two Sr2+ and one Ca2+ atom. In the fifth I1- site, I1- is bonded in a 3-coordinate geometry to two Sr2+ and one Ca2+ atom. In the sixth I1- site, I1- is bonded in a 4-coordinate geometry to three Sr2+ and one Ca2+ atom.