Materials Data on Ba2NaCu3S5 by Materials Project
NaBa2Cu3S5 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Na1+ is bonded to six S2- atoms to form distorted NaS6 pentagonal pyramids that share corners with two equivalent NaS6 pentagonal pyramids, corners with eight CuS4 tetrahedra, and edges with four CuS4 tetrahedra. There are a spread of Na–S bond distances ranging from 2.89–3.03 Å. There are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.12–3.41 Å. In the second Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.14–3.40 Å. There are two inequivalent Cu+1.67+ sites. In the first Cu+1.67+ site, Cu+1.67+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with two equivalent NaS6 pentagonal pyramids, corners with four equivalent CuS4 tetrahedra, edges with two equivalent NaS6 pentagonal pyramids, and edges with four CuS4 tetrahedra. There are two shorter (2.40 Å) and two longer (2.46 Å) Cu–S bond lengths. In the second Cu+1.67+ site, Cu+1.67+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with three equivalent NaS6 pentagonal pyramids, corners with four CuS4 tetrahedra, an edgeedge with one NaS6 pentagonal pyramid, and edges with four CuS4 tetrahedra. There are a spread of Cu–S bond distances ranging from 2.40–2.47 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a 8-coordinate geometry to one Na1+, three Ba2+, and four equivalent Cu+1.67+ atoms. In the second S2- site, S2- is bonded in a 6-coordinate geometry to one Na1+, four Ba2+, and one S2- atom. The S–S bond length is 2.12 Å. In the third S2- site, S2- is bonded in a 8-coordinate geometry to two equivalent Na1+, two Ba2+, and four Cu+1.67+ atoms. In the fourth S2- site, S2- is bonded in a 8-coordinate geometry to one Na1+, three Ba2+, and four Cu+1.67+ atoms.