DOE OSTI2020
Na5InS4 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to four S2- atoms to form NaS4 tetrahedra that share corners with four equivalent NaS6 octahedra, corners with three equivalent NaS5 square pyramids, corners with two equivalent InS4 tetrahedra, corners with four NaS4 tetrahedra, an edgeedge with one NaS6 octahedra, an edgeedge with one NaS5 square pyramid, an edgeedge with one InS4 tetrahedra, and edges with two NaS4 tetrahedra. The corner-sharing octahedra tilt angles range from 16–57°. There are a spread of Na–S bond distances ranging from 2.73–2.92 Å. In the second Na1+ site, Na1+ is bonded to five S2- atoms to form NaS5 square pyramids that share corners with two equivalent NaS6 octahedra, corners with three equivalent InS4 tetrahedra, corners with nine NaS4 tetrahedra, edges with two equivalent NaS6 octahedra, edges with two equivalent NaS5 square pyramids, an edgeedge with one InS4 tetrahedra, and edges with three NaS4 tetrahedra. The corner-sharing octahedral tilt angles are 82°. There are a spread of Na–S bond distances ranging from 2.88–3.20 Å. In the third Na1+ site, Na1+ is bonded to four S2- atoms to form NaS4 tetrahedra that share corners with two equivalent NaS6 octahedra, corners with three equivalent NaS5 square pyramids, corners with two equivalent InS4 tetrahedra, corners with four equivalent NaS4 tetrahedra, edges with two equivalent NaS6 octahedra, an edgeedge with one NaS5 square pyramid, an edgeedge with one InS4 tetrahedra, and edges with two equivalent NaS4 tetrahedra. The corner-sharing octahedral tilt angles are 54°. There are a spread of Na–S bond distances ranging from 2.71–2.96 Å. In the fourth Na1+ site, Na1+ is bonded to six S2- atoms to form NaS6 octahedra that share corners with two equivalent NaS5 square pyramids, corners with two equivalent InS4 tetrahedra, corners with ten NaS4 tetrahedra, edges with two equivalent NaS6 octahedra, edges with two equivalent NaS5 square pyramids, edges with two equivalent InS4 tetrahedra, and edges with four NaS4 tetrahedra. There are a spread of Na–S bond distances ranging from 2.91–3.22 Å. In3+ is bonded to four S2- atoms to form InS4 tetrahedra that share corners with two equivalent NaS6 octahedra, corners with three equivalent NaS5 square pyramids, corners with six NaS4 tetrahedra, edges with two equivalent NaS6 octahedra, an edgeedge with one NaS5 square pyramid, and edges with three NaS4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. There are a spread of In–S bond distances ranging from 2.49–2.52 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a 6-coordinate geometry to five Na1+ and one In3+ atom. In the second S2- site, S2- is bonded in a 7-coordinate geometry to six Na1+ and one In3+ atom. In the third S2- site, S2- is bonded in a 7-coordinate geometry to six Na1+ and one In3+ atom.