Materials Data on Ba2HgS3 by Materials Project

Ba2HgS3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to seven S2- atoms to form distorted BaS7 pentagonal bipyramids that share corners with three equivalent BaS7 pentagonal bipyramids, corners with four equivalent HgS4 tetrahedra, edges with eleven BaS7 pentagonal bipyramids, and edges with three equivalent HgS4 tetrahedra. There are a spread of Ba–S bond distances ranging from 3.14–3.46 Å. In the second Ba2+ site, Ba2+ is bonded to seven S2- atoms to form distorted BaS7 pentagonal bipyramids that share corners with seven BaS7 pentagonal bipyramids, edges with seven BaS7 pentagonal bipyramids, edges with four equivalent HgS4 tetrahedra, and faces with two equivalent BaS7 pentagonal bipyramids. There are a spread of Ba–S bond distances ranging from 3.25–3.38 Å. Hg2+ is bonded to four S2- atoms to form HgS4 tetrahedra that share corners with four equivalent BaS7 pentagonal bipyramids, corners with two equivalent HgS4 tetrahedra, and edges with seven BaS7 pentagonal bipyramids. There are a spread of Hg–S bond distances ranging from 2.58–2.63 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded to five Ba2+ and one Hg2+ atom to form a mixture of distorted edge, face, and corner-sharing SBa5Hg octahedra. The corner-sharing octahedra tilt angles range from 21–57°. In the second S2- site, S2- is bonded in a 6-coordinate geometry to four Ba2+ and two equivalent Hg2+ atoms. In the third S2- site, S2- is bonded to five Ba2+ and one Hg2+ atom to form a mixture of distorted edge, face, and corner-sharing SBa5Hg octahedra. The corner-sharing octahedra tilt angles range from 52–57°.