Materials Data on BaSr2I6 by Materials Project

Abstract

BaSr2I6 is Baddeleyite-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Ba2+ is bonded to seven I1- atoms to form distorted BaI7 pentagonal bipyramids that share corners with four equivalent SrI7 pentagonal bipyramids, an edgeedge with one BaI7 pentagonal bipyramid, and edges with two equivalent SrI7 pentagonal bipyramids. There are a spread of Ba–I bond distances ranging from 3.42–3.74 Å. There are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to seven I1- atoms. There are a spread of Sr–I bond distances ranging from 3.27–4.01 Å. In the second Sr2+ site, Sr2+ is bonded to seven I1- atoms to form distorted SrI7 pentagonal bipyramids that share corners with four equivalent BaI7 pentagonal bipyramids, an edgeedge with one SrI7 pentagonal bipyramid, and edges with two equivalent BaI7 pentagonal bipyramids. There are a spread of Sr–I bond distances ranging from 3.30–3.65 Å. There are six inequivalent I1- sites. In the first I1- site, I1- is bonded to one Ba2+ and three Sr2+ atoms to form a mixture of distorted corner and edge-sharing IBaSr3 tetrahedra. In the second I1- site, I1- is bonded in a 3-coordinate geometry to one Ba2+ and three Sr2+ atoms. In the third I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ba2+ and one Sr2+ atom. In the fourth I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to one Ba2+ and two equivalent Sr2+ atoms. In the fifth I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to one Ba2+ and two Sr2+ atoms. In the sixth I1- site, I1- is bonded to one Ba2+ and three Sr2+ atoms to form a mixture of distorted corner and edge-sharing IBaSr3 tetrahedra.