Materials Data on SrCaI4 by Materials Project

Abstract

SrCaI4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Sr2+ is bonded to six I1- atoms to form distorted SrI6 pentagonal pyramids that share corners with two equivalent SrI6 pentagonal pyramids, an edgeedge with one SrI6 pentagonal pyramid, and edges with four equivalent CaI6 pentagonal pyramids. There are a spread of Sr–I bond distances ranging from 3.28–3.36 Å. Ca2+ is bonded to six I1- atoms to form distorted CaI6 pentagonal pyramids that share corners with two equivalent CaI6 pentagonal pyramids, an edgeedge with one CaI6 pentagonal pyramid, and edges with four equivalent SrI6 pentagonal pyramids. There are a spread of Ca–I bond distances ranging from 3.18–3.25 Å. There are four inequivalent I1- sites. In the first I1- site, I1- is bonded in a distorted T-shaped geometry to one Sr2+ and two equivalent Ca2+ atoms. In the second I1- site, I1- is bonded in a distorted T-shaped geometry to two equivalent Sr2+ and one Ca2+ atom. In the third I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to two equivalent Sr2+ and one Ca2+ atom. In the fourth I1- site, I1- is bonded in a distorted T-shaped geometry to one Sr2+ and two equivalent Ca2+ atoms.