Materials Data on KY2CuS4 by Materials Project
KY2CuS4 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of K–S bond distances ranging from 3.12–3.74 Å. Y3+ is bonded to six S2- atoms to form YS6 octahedra that share corners with three equivalent YS6 octahedra, a cornercorner with one CuS4 tetrahedra, edges with five equivalent YS6 octahedra, and edges with two equivalent CuS4 tetrahedra. The corner-sharing octahedra tilt angles range from 0–38°. There are a spread of Y–S bond distances ranging from 2.72–2.83 Å. Cu1+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with two equivalent YS6 octahedra, corners with two equivalent CuS4 tetrahedra, and edges with four equivalent YS6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are two shorter (2.34 Å) and two longer (2.35 Å) Cu–S bond lengths. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded to two equivalent K1+ and four equivalent Y3+ atoms to form a mixture of distorted edge and corner-sharing SK2Y4 octahedra. The corner-sharing octahedra tilt angles range from 4–47°. In the second S2- site, S2- is bonded to two equivalent K1+, three equivalent Y3+, and one Cu1+ atom to form distorted SK2Y3Cu octahedra that share corners with six SK2Y4 octahedra, edges with seven SK2Y4 octahedra, and a faceface with one SK2Y3Cu octahedra. The corner-sharing octahedra tilt angles range from 4–64°. In the third S2- site, S2- is bonded in a 6-coordinate geometry to two equivalent K1+, two equivalent Y3+, and two equivalent Cu1+ atoms.