Materials Data on Ba3Er4O9 by Materials Project
Ba3Er4O9 is Orthorhombic Perovskite-like structured and crystallizes in the trigonal R3 space group. The structure is three-dimensional. there are three inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six O2- atoms. All Ba–O bond lengths are 2.79 Å. In the second Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are three shorter (2.79 Å) and three longer (2.83 Å) Ba–O bond lengths. In the third Ba2+ site, Ba2+ is bonded in a distorted trigonal planar geometry to three equivalent O2- atoms. All Ba–O bond lengths are 2.71 Å. There are four inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are three shorter (2.20 Å) and three longer (2.39 Å) Er–O bond lengths. In the second Er3+ site, Er3+ is bonded to six O2- atoms to form corner-sharing ErO6 octahedra. The corner-sharing octahedral tilt angles are 18°. There are three shorter (2.22 Å) and three longer (2.27 Å) Er–O bond lengths. In the third Er3+ site, Er3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are three shorter (2.20 Å) and three longer (2.42 Å) Er–O bond lengths. In the fourth Er3+ site, Er3+ is bonded to six O2- atoms to form corner-sharing ErO6 octahedra. The corner-sharing octahedral tilt angles are 18°. There are three shorter (2.22 Å) and three longer (2.29 Å) Er–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted see-saw-like geometry to one Ba2+ and three Er3+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+ and three Er3+ atoms. In the third O2- site, O2- is bonded in a 5-coordinate geometry to three Ba2+ and two Er3+ atoms.