Materials Data on BaCaI4 by Materials Project

Abstract

BaCaI4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Ba2+ is bonded to six I1- atoms to form distorted BaI6 pentagonal pyramids that share corners with two equivalent BaI6 pentagonal pyramids, an edgeedge with one BaI6 pentagonal pyramid, and edges with four equivalent CaI6 pentagonal pyramids. There are a spread of Ba–I bond distances ranging from 3.46–3.50 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 BaI6 pentagonal pyramids. There are a spread of Ca–I bond distances ranging from 3.17–3.25 Å. There are four inequivalent I1- sites. In the first I1- site, I1- is bonded in a distorted T-shaped geometry to one Ba2+ and two equivalent Ca2+ atoms. In the second I1- site, I1- is bonded in a 3-coordinate geometry to two equivalent Ba2+ and one Ca2+ atom. In the third I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ba2+ and one Ca2+ atom. In the fourth I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to one Ba2+ and two equivalent Ca2+ atoms.