Materials Data on Ba2Na(SnAs)6 by Materials Project

Abstract

NaBa2(SnAs)6 crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of one NaBa2(SnAs)6 sheet oriented in the (0, 0, 1) direction. Na1+ is bonded to six As3- atoms to form NaAs6 octahedra that share edges with six equivalent BaAs6 octahedra. All Na–As bond lengths are 3.25 Å. Ba2+ is bonded to six As3- atoms to form BaAs6 octahedra that share edges with three equivalent NaAs6 octahedra and edges with three equivalent BaAs6 octahedra. All Ba–As bond lengths are 3.29 Å. There are two inequivalent Sn+2.17+ sites. In the first Sn+2.17+ site, Sn+2.17+ is bonded in a distorted trigonal non-coplanar geometry to three As3- atoms. There are a spread of Sn–As bond distances ranging from 2.78–2.82 Å. In the second Sn+2.17+ site, Sn+2.17+ is bonded in a distorted trigonal non-coplanar geometry to three As3- atoms. There are two shorter (2.78 Å) and one longer (2.82 Å) Sn–As bond lengths. There are two inequivalent As3- sites. In the first As3- site, As3- is bonded to one Na1+, two equivalent Ba2+, and three Sn+2.17+ atoms to form a mixture of edge and corner-sharing AsBa2NaSn3 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the second As3- site, As3- is bonded to one Na1+, two equivalent Ba2+, and three Sn+2.17+ atoms to form a mixture of edge and corner-sharing AsBa2NaSn3 octahedra. The corner-sharing octahedra tilt angles range from 0–1°.