Materials Data on CaLaI5 by Materials Project

Abstract

CaLaI5 crystallizes in the orthorhombic Cmcm space group. The structure is two-dimensional and consists of two CaLaI5 sheets oriented in the (0, 1, 0) direction. Ca2+ is bonded to six I1- atoms to form distorted CaI6 pentagonal pyramids that share corners with four equivalent LaI6 octahedra and faces with two equivalent CaI6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 73°. There are two shorter (3.08 Å) and four longer (3.39 Å) Ca–I bond lengths. La3+ is bonded to six I1- atoms to form LaI6 octahedra that share corners with four equivalent CaI6 pentagonal pyramids and edges with two equivalent LaI6 octahedra. There are four shorter (3.18 Å) and two longer (3.20 Å) La–I bond lengths. There are three inequivalent I1- sites. In the first I1- site, I1- is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ca2+ and one La3+ atom. In the second I1- site, I1- is bonded in an L-shaped geometry to two equivalent Ca2+ atoms. In the third I1- site, I1- is bonded in an L-shaped geometry to two equivalent La3+ atoms.