Materials Data on NaSm3SiS7 by Materials Project
NaSm3SiS7 crystallizes in the hexagonal P6_3 space group. The structure is three-dimensional. Na1+ is bonded to six equivalent S2- atoms to form face-sharing NaS6 octahedra. There are three shorter (2.73 Å) and three longer (2.74 Å) Na–S bond lengths. Sm3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Sm–S bond distances ranging from 2.85–3.13 Å. Si4+ is bonded in a tetrahedral geometry to four S2- atoms. There are one shorter (2.12 Å) and three longer (2.15 Å) Si–S bond lengths. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a 6-coordinate geometry to two equivalent Na1+ and four equivalent Sm3+ atoms. In the second S2- site, S2- is bonded in a 4-coordinate geometry to three equivalent Sm3+ and one Si4+ atom. In the third S2- site, S2- is bonded in a distorted tetrahedral geometry to three equivalent Sm3+ and one Si4+ atom.