Materials Data on K3Cu2(BiS2)5 by Materials Project

Abstract

K3Bi5Cu2S10 crystallizes in the orthorhombic Pnnm space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of K–S bond distances ranging from 3.26–3.74 Å. In the second K1+ site, K1+ is bonded to six S2- atoms to form distorted KS6 octahedra that share corners with four equivalent BiS6 octahedra, corners with two equivalent CuS4 tetrahedra, edges with two equivalent KS6 octahedra, and edges with six BiS6 octahedra. The corner-sharing octahedral tilt angles are 13°. There are two shorter (3.16 Å) and four longer (3.17 Å) K–S bond lengths. Cu1+ is bonded to four S2- atoms to form CuS4 tetrahedra that share a cornercorner with one KS6 octahedra, a cornercorner with one BiS6 octahedra, corners with two equivalent CuS4 tetrahedra, and edges with four BiS6 octahedra. The corner-sharing octahedra tilt angles range from 5–14°. There are a spread of Cu–S bond distances ranging from 2.35–2.64 Å. There are three inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share a cornercorner with one BiS6 octahedra, corners with two equivalent KS6 octahedra, an edgeedge with one KS6 octahedra, edges with six BiS6 octahedra, and edges with two equivalent CuS4 tetrahedra. The corner-sharing octahedra tilt angles range from 13–44°. There are a spread of Bi–S bond distances ranging from 2.71–3.02 Å. In the second Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with three BiS6 octahedra, edges with two equivalent KS6 octahedra, edges with five BiS6 octahedra, and edges with two equivalent CuS4 tetrahedra. The corner-sharing octahedra tilt angles range from 5–44°. There are a spread of Bi–S bond distances ranging from 2.70–3.07 Å. In the third Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with four equivalent BiS6 octahedra, corners with two equivalent CuS4 tetrahedra, and edges with eight BiS6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are two shorter (2.84 Å) and four longer (2.86 Å) Bi–S bond lengths. There are five inequivalent S2- sites. In the first S2- site, S2- is bonded in a 6-coordinate geometry to two equivalent K1+, two equivalent Cu1+, and two Bi3+ atoms. In the second S2- site, S2- is bonded to one K1+ and five Bi3+ atoms to form SKBi5 octahedra that share corners with six SKBi5 octahedra, edges with eight SKBi5 octahedra, and edges with two equivalent SK2Bi3 square pyramids. The corner-sharing octahedra tilt angles range from 0–43°. In the third S2- site, S2- is bonded to two equivalent K1+ and three Bi3+ atoms to form SK2Bi3 square pyramids that share corners with four SK2CuBi3 octahedra, corners with two equivalent SK2Bi3 square pyramids, edges with five SK2CuBi3 octahedra, and edges with three equivalent SK2Bi3 square pyramids. The corner-sharing octahedra tilt angles range from 6–77°. In the fourth S2- site, S2- is bonded to two equivalent K1+, one Cu1+, and three Bi3+ atoms to form distorted SK2CuBi3 octahedra that share corners with three SK2CuBi3 octahedra, corners with two equivalent SK2Bi3 square pyramids, edges with six SK2CuBi3 octahedra, an edgeedge with one SK2Bi3 square pyramid, and a faceface with one SK3CuBi2 octahedra. The corner-sharing octahedra tilt angles range from 0–68°. In the fifth S2- site, S2- is bonded to three K1+, one Cu1+, and two equivalent Bi3+ atoms to form distorted SK3CuBi2 octahedra that share corners with seven SKBi5 octahedra, corners with two equivalent SK2Bi3 square pyramids, edges with three SKBi5 octahedra, edges with two equivalent SK2Bi3 square pyramids, and a faceface with one SK2CuBi3 octahedra. The corner-sharing octahedra tilt angles range from 0–68°.