Materials Data on Na2HgS2 by Materials Project
Na2HgS2 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six S2- atoms to form distorted NaS6 octahedra that share corners with four equivalent NaS6 octahedra, corners with five equivalent NaS4 tetrahedra, edges with two equivalent NaS6 octahedra, an edgeedge with one NaS4 tetrahedra, faces with two equivalent NaS6 octahedra, and a faceface with one NaS4 tetrahedra. The corner-sharing octahedra tilt angles range from 39–44°. There are a spread of Na–S bond distances ranging from 2.95–3.35 Å. In the second Na1+ site, Na1+ is bonded to four S2- atoms to form distorted NaS4 tetrahedra that share corners with five equivalent NaS6 octahedra, corners with six equivalent NaS4 tetrahedra, an edgeedge with one NaS6 octahedra, and a faceface with one NaS6 octahedra. The corner-sharing octahedra tilt angles range from 8–65°. There are a spread of Na–S bond distances ranging from 2.77–2.91 Å. Hg2+ is bonded in a distorted linear geometry to three S2- atoms. There are a spread of Hg–S bond distances ranging from 2.35–3.40 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a 7-coordinate geometry to five Na1+ and two equivalent Hg2+ atoms. In the second S2- site, S2- is bonded in a 6-coordinate geometry to five Na1+ and one Hg2+ atom.