Materials Data on BaLaI5 by Materials Project
BaLaI5 crystallizes in the monoclinic P2_1/m space group. The structure is two-dimensional and consists of one BaLaI5 sheet oriented in the (-1, 0, 1) direction. Ba2+ is bonded to seven I1- atoms to form distorted BaI7 pentagonal bipyramids that share edges with two equivalent BaI7 pentagonal bipyramids, edges with two equivalent LaI7 pentagonal bipyramids, and faces with two equivalent BaI7 pentagonal bipyramids. There are a spread of Ba–I bond distances ranging from 3.45–3.67 Å. La3+ is bonded to seven I1- atoms to form distorted LaI7 pentagonal bipyramids that share edges with two equivalent BaI7 pentagonal bipyramids and edges with four equivalent LaI7 pentagonal bipyramids. There are a spread of La–I bond distances ranging from 3.20–3.39 Å. There are five inequivalent I1- sites. In the first I1- site, I1- is bonded in a 3-coordinate geometry to two equivalent Ba2+ and one La3+ atom. In the second I1- site, I1- is bonded in a distorted T-shaped geometry to three equivalent Ba2+ 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 Ba2+ and one La3+ atom. In the fifth I1- site, I1- is bonded in a water-like geometry to two equivalent La3+ atoms.