Materials Data on KGd2CuS4 by Materials Project
KGd2CuS4 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 3.16–3.76 Å. Gd3+ is bonded to six S2- atoms to form GdS6 octahedra that share corners with three equivalent GdS6 octahedra, a cornercorner with one CuS4 tetrahedra, edges with five equivalent GdS6 octahedra, and edges with two equivalent CuS4 tetrahedra. The corner-sharing octahedra tilt angles range from 0–37°. There are a spread of Gd–S bond distances ranging from 2.74–2.85 Å. Cu1+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with two equivalent GdS6 octahedra, corners with two equivalent CuS4 tetrahedra, and edges with four equivalent GdS6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are two shorter (2.34 Å) and two longer (2.37 Å) Cu–S bond lengths. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded to two equivalent K1+, three equivalent Gd3+, and one Cu1+ atom to form a mixture of distorted corner, edge, and face-sharing SK2Gd3Cu octahedra. The corner-sharing octahedra tilt angles range from 3–65°. In the second S2- site, S2- is bonded to two equivalent K1+ and four equivalent Gd3+ atoms to form a mixture of distorted corner and edge-sharing SK2Gd4 octahedra. The corner-sharing octahedra tilt angles range from 3–46°. In the third S2- site, S2- is bonded in a 6-coordinate geometry to two equivalent K1+, two equivalent Gd3+, and two equivalent Cu1+ atoms.