Materials Data on Ba9(RhO3)8 by Materials Project

Abstract

Ba9Rh8O24 crystallizes in the trigonal R-3c space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.68–3.20 Å. In the second Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ba–O bond distances ranging from 2.66–2.90 Å. There are five inequivalent Rh+3.75+ sites. In the first Rh+3.75+ site, Rh+3.75+ is bonded to six O2- atoms to form face-sharing RhO6 octahedra. There are three shorter (2.04 Å) and three longer (2.08 Å) Rh–O bond lengths. In the second Rh+3.75+ site, Rh+3.75+ is bonded to six O2- atoms to form face-sharing RhO6 octahedra. There are three shorter (2.05 Å) and three longer (2.07 Å) Rh–O bond lengths. In the third Rh+3.75+ site, Rh+3.75+ is bonded to six equivalent O2- atoms to form distorted face-sharing RhO6 octahedra. All Rh–O bond lengths are 2.06 Å. In the fourth Rh+3.75+ site, Rh+3.75+ is bonded to six O2- atoms to form distorted face-sharing RhO6 octahedra. There are three shorter (2.03 Å) and three longer (2.08 Å) Rh–O bond lengths. In the fifth Rh+3.75+ site, Rh+3.75+ is bonded to six equivalent O2- atoms to form face-sharing RhO6 octahedra. All Rh–O bond lengths are 2.06 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted see-saw-like geometry to two Ba2+ and two Rh+3.75+ atoms. In the second O2- site, O2- is bonded in a 6-coordinate geometry to four Ba2+ and two Rh+3.75+ atoms. In the third O2- site, O2- is bonded to four Ba2+ and two Rh+3.75+ atoms to form a mixture of distorted face and corner-sharing OBa4Rh2 octahedra. The corner-sharing octahedra tilt angles range from 0–28°. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent Ba2+ and two Rh+3.75+ atoms.