Materials Data on CuBi5S8 by Materials Project

Abstract

CuBi5S8 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. Cu1+ is bonded to four S2- atoms to form distorted CuS4 tetrahedra that share corners with two equivalent BiS6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are two shorter (2.35 Å) and two longer (2.37 Å) Cu–S bond lengths. There are three inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with two equivalent BiS6 octahedra, a cornercorner with one CuS4 tetrahedra, and edges with seven BiS6 octahedra. The corner-sharing octahedra tilt angles range from 3–4°. There are a spread of Bi–S bond distances ranging from 2.69–3.16 Å. In the second Bi3+ site, Bi3+ is bonded in a 5-coordinate geometry to five S2- atoms. There are a spread of Bi–S bond distances ranging from 2.60–2.97 Å. In the third Bi3+ site, Bi3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing BiS6 octahedra. The corner-sharing octahedra tilt angles range from 3–4°. There are four shorter (2.83 Å) and two longer (2.84 Å) Bi–S bond lengths. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded to five Bi3+ atoms to form SBi5 square pyramids that share corners with two equivalent SBi5 square pyramids, corners with three equivalent SCuBi3 trigonal pyramids, and edges with five equivalent SBi5 square pyramids. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three Bi3+ atoms. In the third S2- site, S2- is bonded to one Cu1+ and three Bi3+ atoms to form distorted SCuBi3 trigonal pyramids that share corners with three equivalent SBi5 square pyramids and corners with three equivalent SCuBi3 trigonal pyramids. In the fourth S2- site, S2- is bonded in a 4-coordinate geometry to one Cu1+ and three equivalent Bi3+ atoms.