Materials Data on Bi8Rh8O27 by Materials Project
Rh8Bi8O27 crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are four inequivalent Rh+3.75+ sites. In the first Rh+3.75+ site, Rh+3.75+ is bonded to six O2- atoms to form RhO6 octahedra that share corners with six RhO6 octahedra and edges with four BiO7 hexagonal pyramids. The corner-sharing octahedra tilt angles range from 50–52°. There are a spread of Rh–O bond distances ranging from 2.01–2.05 Å. In the second Rh+3.75+ site, Rh+3.75+ is bonded to six O2- atoms to form RhO6 octahedra that share corners with six RhO6 octahedra and edges with six equivalent BiO7 hexagonal pyramids. The corner-sharing octahedra tilt angles range from 50–52°. There are three shorter (2.00 Å) and three longer (2.06 Å) Rh–O bond lengths. In the third Rh+3.75+ site, Rh+3.75+ is bonded to six O2- atoms to form RhO6 octahedra that share corners with six RhO6 octahedra and edges with two equivalent BiO7 hexagonal pyramids. The corner-sharing octahedra tilt angles range from 50–52°. There are a spread of Rh–O bond distances ranging from 2.01–2.05 Å. In the fourth Rh+3.75+ site, Rh+3.75+ is bonded to six O2- atoms to form corner-sharing RhO6 octahedra. The corner-sharing octahedra tilt angles range from 50–51°. There are three shorter (2.02 Å) and three longer (2.03 Å) Rh–O bond lengths. There are four inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to seven O2- atoms to form distorted BiO7 hexagonal pyramids that share corners with three equivalent BiO7 hexagonal pyramids and edges with six equivalent RhO6 octahedra. There are a spread of Bi–O bond distances ranging from 2.15–2.52 Å. In the second Bi3+ site, Bi3+ is bonded to seven O2- atoms to form distorted BiO7 hexagonal pyramids that share corners with three BiO7 hexagonal pyramids, edges with two equivalent BiO7 hexagonal pyramids, and edges with six RhO6 octahedra. There are a spread of Bi–O bond distances ranging from 2.25–2.53 Å. In the third Bi3+ site, Bi3+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Bi–O bond distances ranging from 2.24–2.53 Å. In the fourth Bi3+ site, Bi3+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Bi–O bond distances ranging from 2.27–2.54 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded to two Rh+3.75+ and two equivalent Bi3+ atoms to form distorted OBi2Rh2 tetrahedra that share corners with seven OBi2Rh2 tetrahedra and an edgeedge with one OBi4 tetrahedra. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Rh+3.75+ and two Bi3+ atoms. In the third O2- site, O2- is bonded to four Bi3+ atoms to form corner-sharing OBi4 tetrahedra. In the fourth O2- site, O2- is bonded to four Bi3+ atoms to form OBi4 tetrahedra that share a cornercorner with one OBi4 tetrahedra and edges with six OBi2Rh2 tetrahedra. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Rh+3.75+ and two Bi3+ atoms. In the sixth O2- site, O2- is bonded to two Rh+3.75+ and two equivalent Bi3+ atoms to form distorted OBi2Rh2 tetrahedra that share corners with seven OBi2Rh2 tetrahedra and an edgeedge with one OBi4 tetrahedra. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to two Rh+3.75+ and two equivalent Bi3+ atoms. In the eighth O2- site, O2- is bonded to four Bi3+ atoms to form OBi4 tetrahedra that share corners with seven OBi4 tetrahedra and edges with three equivalent OBi2Rh2 tetrahedra. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Rh+3.75+ and two Bi3+ atoms. In the tenth O2- site, O2- is bonded to two equivalent Rh+3.75+ and two Bi3+ atoms to form distorted OBi2Rh2 tetrahedra that share corners with seven OBi2Rh2 tetrahedra and an edgeedge with one OBi4 tetrahedra. In the eleventh O2- site, O2- is bonded in a 4-coordinate geometry to two Rh+3.75+ and two equivalent Bi3+ atoms.