Materials Data on Na9Sn4 by Materials Project

Abstract

Na9Sn4 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are five inequivalent Na sites. In the first Na site, Na is bonded in a 6-coordinate geometry to two equivalent Na and six equivalent Sn atoms. Both Na–Na bond lengths are 3.32 Å. There are four shorter (3.43 Å) and two longer (3.51 Å) Na–Sn bond lengths. In the second Na site, Na is bonded to three equivalent Na and four Sn atoms to form distorted edge-sharing NaNa3Sn4 tetrahedra. There are one shorter (3.39 Å) and two longer (3.44 Å) Na–Na bond lengths. There are a spread of Na–Sn bond distances ranging from 3.24–3.38 Å. In the third Na site, Na is bonded in a 4-coordinate geometry to three equivalent Na and four Sn atoms. There are two shorter (3.29 Å) and one longer (3.32 Å) Na–Na bond lengths. There are a spread of Na–Sn bond distances ranging from 3.26–3.52 Å. In the fourth Na site, Na is bonded in a 11-coordinate geometry to eight Na and three equivalent Sn atoms. The Na–Na bond length is 3.36 Å. There are one shorter (3.61 Å) and two longer (3.70 Å) Na–Sn bond lengths. In the fifth Na site, Na is bonded in a distorted trigonal non-coplanar geometry to one Na and three equivalent Sn atoms. There are one shorter (3.24 Å) and two longer (3.26 Å) Na–Sn bond lengths. There are two inequivalent Sn sites. In the first Sn site, Sn is bonded in a 11-coordinate geometry to ten Na and one Sn atom. The Sn–Sn bond length is 2.84 Å. In the second Sn site, Sn is bonded in a 8-coordinate geometry to seven Na and one Sn atom. The Sn–Sn bond length is 2.97 Å.