DOE OSTI2020
Ba2CoS3 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 six BaS7 pentagonal bipyramids, a cornercorner with one CoS4 tetrahedra, edges with ten BaS7 pentagonal bipyramids, and edges with four equivalent CoS4 tetrahedra. There are a spread of Ba–S bond distances ranging from 3.17–3.23 Å. In the second Ba2+ site, Ba2+ is bonded to seven S2- atoms to form distorted BaS7 pentagonal bipyramids that share corners with four equivalent BaS7 pentagonal bipyramids, corners with three equivalent CoS4 tetrahedra, edges with eight BaS7 pentagonal bipyramids, edges with three equivalent CoS4 tetrahedra, and faces with two equivalent BaS7 pentagonal bipyramids. There are a spread of Ba–S bond distances ranging from 3.20–3.31 Å. Co2+ is bonded to four S2- atoms to form CoS4 tetrahedra that share corners with four BaS7 pentagonal bipyramids, corners with two equivalent CoS4 tetrahedra, and edges with seven BaS7 pentagonal bipyramids. There are a spread of Co–S bond distances ranging from 2.27–2.37 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a 6-coordinate geometry to four Ba2+ and two equivalent Co2+ atoms. In the second S2- site, S2- is bonded to five Ba2+ and one Co2+ atom to form a mixture of distorted edge, face, and corner-sharing SBa5Co octahedra. The corner-sharing octahedra tilt angles range from 26–58°. In the third S2- site, S2- is bonded to five Ba2+ and one Co2+ atom to form a mixture of distorted edge, face, and corner-sharing SBa5Co octahedra. The corner-sharing octahedra tilt angles range from 26–58°.