Materials Data on Sr2CaI6 by Materials Project

Abstract

Sr2CaI6 is Hydrophilite-derived structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to six I1- atoms to form SrI6 octahedra that share corners with six SrI6 octahedra, corners with two equivalent CaI6 pentagonal pyramids, an edgeedge with one SrI6 octahedra, and an edgeedge with one CaI6 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 52–69°. There are a spread of Sr–I bond distances ranging from 3.25–3.45 Å. In the second Sr2+ site, Sr2+ is bonded to six I1- atoms to form SrI6 octahedra that share corners with six SrI6 octahedra, corners with two equivalent CaI6 pentagonal pyramids, an edgeedge with one SrI6 octahedra, and an edgeedge with one CaI6 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 52–69°. There are a spread of Sr–I bond distances ranging from 3.25–3.47 Å. In the third Sr2+ site, Sr2+ is bonded to six I1- atoms to form SrI6 octahedra that share corners with six SrI6 octahedra, corners with two equivalent CaI6 pentagonal pyramids, an edgeedge with one SrI6 octahedra, and an edgeedge with one CaI6 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 51–69°. There are a spread of Sr–I bond distances ranging from 3.25–3.44 Å. In the fourth Sr2+ site, Sr2+ is bonded to six I1- atoms to form SrI6 octahedra that share corners with six SrI6 octahedra, corners with two equivalent CaI6 pentagonal pyramids, an edgeedge with one SrI6 octahedra, and an edgeedge with one CaI6 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 51–69°. There are a spread of Sr–I bond distances ranging from 3.25–3.46 Å. There are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six I1- atoms to form distorted CaI6 pentagonal pyramids that share corners with four SrI6 octahedra, edges with two SrI6 octahedra, and edges with two equivalent CaI6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 42–56°. There are a spread of Ca–I bond distances ranging from 3.18–3.26 Å. In the second Ca2+ site, Ca2+ is bonded to six I1- atoms to form distorted CaI6 pentagonal pyramids that share corners with four SrI6 octahedra, edges with two SrI6 octahedra, and edges with two equivalent CaI6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 42–56°. There are a spread of Ca–I bond distances ranging from 3.19–3.25 Å. There are twelve inequivalent I1- sites. In the first I1- site, I1- is bonded in a trigonal non-coplanar geometry to one Sr2+ and two Ca2+ atoms. In the second I1- site, I1- is bonded in a trigonal non-coplanar geometry to one Sr2+ and two Ca2+ atoms. In the third I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to two Sr2+ and one Ca2+ atom. In the fourth I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to two Sr2+ and one Ca2+ atom. In the fifth I1- site, I1- is bonded in a distorted trigonal planar geometry to three Sr2+ atoms. In the sixth I1- site, I1- is bonded in a distorted trigonal planar geometry to three Sr2+ atoms. In the seventh I1- site, I1- is bonded in a distorted trigonal planar geometry to three Sr2+ atoms. In the eighth I1- site, I1- is bonded in a distorted trigonal planar geometry to three Sr2+ atoms. In the ninth I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to two Sr2+ and one Ca2+ atom. In the tenth I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to two Sr2+ and one Ca2+ atom. In the eleventh I1- site, I1- is bonded in a trigonal non-coplanar geometry to one Sr2+ and two Ca2+ atoms. In the twelfth I1- site, I1- is bonded in a trigonal non-coplanar geometry to one Sr2+ and two Ca2+ atoms.