Materials Data on BaLa2Br8 by Materials Project
BaLa2Br8 crystallizes in the tetragonal I-4 space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 4-coordinate geometry to four equivalent Br1- atoms. All Ba–Br bond lengths are 3.22 Å. In the second Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight Br1- atoms. There are four shorter (3.25 Å) and four longer (3.70 Å) Ba–Br bond lengths. La3+ is bonded to seven Br1- atoms to form a mixture of edge and corner-sharing LaBr7 pentagonal bipyramids. There are a spread of La–Br bond distances ranging from 2.84–3.16 Å. There are four inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a distorted trigonal non-coplanar geometry to one Ba2+ and two equivalent La3+ atoms. In the second Br1- site, Br1- is bonded in a 3-coordinate geometry to one Ba2+ and two equivalent La3+ atoms. In the third Br1- site, Br1- is bonded in a bent 120 degrees geometry to two equivalent La3+ atoms. In the fourth Br1- site, Br1- is bonded in a bent 120 degrees geometry to one Ba2+ and one La3+ atom.