Materials Data on RbBi4Se7 by Materials Project
RbBi4Se7 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Rb1+ is bonded in a 6-coordinate geometry to six Se2- atoms. There are a spread of Rb–Se bond distances ranging from 3.43–3.80 Å. There are four inequivalent Bi+3.25+ sites. In the first Bi+3.25+ site, Bi+3.25+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedra tilt angles range from 2–5°. There are a spread of Bi–Se bond distances ranging from 2.87–3.06 Å. In the second Bi+3.25+ site, Bi+3.25+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are a spread of Bi–Se bond distances ranging from 2.77–3.18 Å. In the third Bi+3.25+ site, Bi+3.25+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedra tilt angles range from 5–6°. There are a spread of Bi–Se bond distances ranging from 2.81–3.16 Å. In the fourth Bi+3.25+ site, Bi+3.25+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedral tilt angles are 6°. There are a spread of Bi–Se bond distances ranging from 2.85–3.15 Å. There are seven inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 3-coordinate geometry to two equivalent Bi+3.25+ and one Se2- atom. The Se–Se bond length is 2.39 Å. In the second Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to four Bi+3.25+ atoms. In the third Se2- site, Se2- is bonded to two equivalent Rb1+ and three equivalent Bi+3.25+ atoms to form a mixture of corner and edge-sharing SeRb2Bi3 square pyramids. In the fourth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to one Rb1+ and three Bi+3.25+ atoms. In the fifth Se2- site, Se2- is bonded to two equivalent Rb1+ and three Bi+3.25+ atoms to form SeRb2Bi3 square pyramids that share a cornercorner with one SeBi6 octahedra, corners with two equivalent SeRb2Bi3 square pyramids, edges with two equivalent SeBi6 octahedra, and edges with three SeRb2Bi3 square pyramids. The corner-sharing octahedral tilt angles are 10°. In the sixth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Rb1+ and three Bi+3.25+ atoms. In the seventh Se2- site, Se2- is bonded to six Bi+3.25+ atoms to form SeBi6 octahedra that share a cornercorner with one SeRb2Bi3 square pyramid, edges with four equivalent SeBi6 octahedra, and edges with two equivalent SeRb2Bi3 square pyramids.