Materials Data on NaAsS2 by Materials Project
NaAsS2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Na1+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing NaS6 octahedra. The corner-sharing octahedra tilt angles range from 16–21°. There are a spread of Na–S bond distances ranging from 2.86–3.08 Å. As3+ is bonded in a trigonal non-coplanar geometry to three S2- atoms. There are a spread of As–S bond distances ranging from 2.20–2.37 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a see-saw-like geometry to two equivalent Na1+ and two equivalent As3+ atoms. In the second S2- site, S2- is bonded to four equivalent Na1+ and one As3+ atom to form a mixture of edge and corner-sharing SNa4As square pyramids.