Materials Data on TaCuS3 by Materials Project
CuTaS3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ta5+ is bonded to six S2- atoms to form distorted TaS6 octahedra that share corners with three equivalent CuS4 tetrahedra, edges with four equivalent TaS6 octahedra, and edges with two equivalent CuS4 tetrahedra. There are a spread of Ta–S bond distances ranging from 2.30–2.75 Å. Cu1+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with three equivalent TaS6 octahedra, corners with two equivalent CuS4 tetrahedra, and edges with two equivalent TaS6 octahedra. The corner-sharing octahedra tilt angles range from 58–62°. There are three shorter (2.29 Å) and one longer (2.30 Å) Cu–S bond lengths. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded to three equivalent Ta5+ and one Cu1+ atom to form a mixture of distorted edge and corner-sharing STa3Cu tetrahedra. In the second S2- site, S2- is bonded in a 3-coordinate geometry to one Ta5+ and two equivalent Cu1+ atoms. In the third S2- site, S2- is bonded in a distorted T-shaped geometry to two equivalent Ta5+ and one Cu1+ atom.