Materials Data on Ba5Al5Sn by Materials Project
Ba5Al5Sn crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. there are three inequivalent Ba sites. In the first Ba site, Ba is bonded in a 9-coordinate geometry to seven Ba, six Al, and three equivalent Sn atoms. There are a spread of Ba–Ba bond distances ranging from 3.81–4.46 Å. There are three shorter (3.74 Å) and three longer (3.78 Å) Ba–Al bond lengths. All Ba–Sn bond lengths are 4.17 Å. In the second Ba site, Ba is bonded in a 4-coordinate geometry to three equivalent Ba, nine Al, and one Sn atom. There are three shorter (3.52 Å) and six longer (3.61 Å) Ba–Al bond lengths. The Ba–Sn bond length is 3.67 Å. In the third Ba site, Ba is bonded to six equivalent Ba, two equivalent Al, and three equivalent Sn atoms to form BaBa6Al2Sn3 trigonal bipyramids that share edges with three equivalent SnBa11 trigonal bipyramids, faces with three equivalent SnBa11 trigonal bipyramids, and faces with six equivalent BaBa6Al2Sn3 trigonal bipyramids. Both Ba–Al bond lengths are 3.61 Å. All Ba–Sn bond lengths are 3.52 Å. There are two inequivalent Al sites. In the first Al site, Al is bonded in a distorted q6 geometry to six Ba and four Al atoms. There are two shorter (2.74 Å) and two longer (2.84 Å) Al–Al bond lengths. In the second Al site, Al is bonded in a 10-coordinate geometry to seven Ba and three equivalent Al atoms. Sn is bonded to eleven Ba atoms to form distorted SnBa11 trigonal bipyramids that share edges with three equivalent BaBa6Al2Sn3 trigonal bipyramids, faces with three equivalent BaBa6Al2Sn3 trigonal bipyramids, and faces with six equivalent SnBa11 trigonal bipyramids.