DOE OSTI2020
NaSbS2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Na1+ is bonded to six S2- atoms to form NaS6 octahedra that share corners with four equivalent NaS6 octahedra, corners with five equivalent SbS5 square pyramids, edges with four equivalent NaS6 octahedra, and edges with five equivalent SbS5 square pyramids. The corner-sharing octahedra tilt angles range from 5–12°. There are a spread of Na–S bond distances ranging from 2.81–3.06 Å. Sb3+ is bonded to five S2- atoms to form SbS5 square pyramids that share corners with five equivalent NaS6 octahedra, corners with two equivalent SbS5 square pyramids, edges with five equivalent NaS6 octahedra, and edges with three equivalent SbS5 square pyramids. The corner-sharing octahedra tilt angles range from 2–88°. There are a spread of Sb–S bond distances ranging from 2.45–2.89 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded to three equivalent Na1+ and two equivalent Sb3+ atoms to form SNa3Sb2 square pyramids that share corners with five equivalent SNa3Sb3 octahedra, corners with two equivalent SNa3Sb2 square pyramids, edges with five equivalent SNa3Sb3 octahedra, and edges with three equivalent SNa3Sb2 square pyramids. The corner-sharing octahedra tilt angles range from 2–84°. In the second S2- site, S2- is bonded to three equivalent Na1+ and three equivalent Sb3+ atoms to form SNa3Sb3 octahedra that share corners with four equivalent SNa3Sb3 octahedra, corners with five equivalent SNa3Sb2 square pyramids, edges with four equivalent SNa3Sb3 octahedra, and edges with five equivalent SNa3Sb2 square pyramids. The corner-sharing octahedra tilt angles range from 5–12°.