Materials Data on Ba3SrNb2O9 by Materials Project

Abstract

Ba3SrNb2O9 is Orthorhombic Perovskite-derived structured and crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 12-coordinate geometry to nine O2- atoms. There are three shorter (2.80 Å) and six longer (3.06 Å) Ba–O bond lengths. In the second Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are three shorter (2.72 Å) and three longer (2.84 Å) Ba–O bond lengths. Sr2+ is bonded to six equivalent O2- atoms to form SrO6 octahedra that share corners with six equivalent NbO6 octahedra. The corner-sharing octahedral tilt angles are 24°. All Sr–O bond lengths are 2.47 Å. Nb5+ is bonded to six O2- atoms to form distorted NbO6 octahedra that share corners with three equivalent SrO6 octahedra and a faceface with one NbO6 octahedra. The corner-sharing octahedral tilt angles are 24°. There are three shorter (1.92 Å) and three longer (2.19 Å) Nb–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to three Ba2+ and two equivalent Nb5+ atoms to form a mixture of distorted corner and edge-sharing OBa3Nb2 square pyramids. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two Ba2+, one Sr2+, and one Nb5+ atom.