Materials Data on SrLaI5 by Materials Project

Abstract

SrLaI5 crystallizes in the monoclinic P2_1/m space group. The structure is two-dimensional and consists of one SrLaI5 sheet oriented in the (-1, 0, 1) direction. Sr2+ is bonded to seven I1- atoms to form distorted SrI7 pentagonal bipyramids that share edges with two equivalent SrI7 pentagonal bipyramids, edges with two equivalent LaI7 pentagonal bipyramids, and faces with two equivalent SrI7 pentagonal bipyramids. There are a spread of Sr–I bond distances ranging from 3.31–3.57 Å. La3+ is bonded to seven I1- atoms to form distorted LaI7 pentagonal bipyramids that share edges with two equivalent SrI7 pentagonal bipyramids and edges with four equivalent LaI7 pentagonal bipyramids. There are a spread of La–I bond distances ranging from 3.19–3.44 Å. There are five inequivalent I1- sites. In the first I1- site, I1- is bonded in a 3-coordinate geometry to two equivalent Sr2+ and one La3+ atom. In the second I1- site, I1- is bonded in a distorted T-shaped geometry to three equivalent Sr2+ atoms. In the third I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to three equivalent La3+ atoms. In the fourth I1- site, I1- is bonded in a 3-coordinate geometry to two equivalent Sr2+ and one La3+ atom. In the fifth I1- site, I1- is bonded in an L-shaped geometry to two equivalent La3+ atoms.