Materials Data on Ba2SrI6 by Materials Project

Abstract

Ba2SrI6 is Baddeleyite-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 7-coordinate geometry to seven I1- atoms. There are a spread of Ba–I bond distances ranging from 3.46–3.76 Å. In the second Ba2+ site, 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 3.44–3.73 Å. 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 3.28–3.86 Å. There are six inequivalent I1- sites. In the first I1- site, I1- is bonded to three Ba2+ and one Sr2+ atom to form a mixture of corner and edge-sharing IBa3Sr tetrahedra. In the second I1- site, I1- is bonded to three Ba2+ and one Sr2+ atom to form a mixture of distorted corner and edge-sharing IBa3Sr tetrahedra. In the third I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to one Ba2+ and two equivalent Sr2+ atoms. In the fourth I1- site, I1- is bonded in a distorted trigonal planar geometry to two equivalent Ba2+ and one Sr2+ atom. In the fifth I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to two Ba2+ and one Sr2+ atom. In the sixth I1- site, I1- is bonded in a 4-coordinate geometry to three Ba2+ and one Sr2+ atom.