Materials Data on Ba3NaIr2O9 by Materials Project

Abstract

Ba3NaIr2O9 is (Cubic) Perovskite-derived structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Na is bonded to six equivalent O atoms to form NaO6 octahedra that share corners with six equivalent IrO6 octahedra and faces with eight BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 1°. All Na–O bond lengths are 2.27 Å. There are two inequivalent Ba sites. In the first Ba site, Ba is bonded to twelve O atoms to form BaO12 cuboctahedra that share corners with nine BaO12 cuboctahedra, corners with three equivalent IrO6 octahedra, faces with seven BaO12 cuboctahedra, faces with three equivalent NaO6 octahedra, and faces with four equivalent IrO6 octahedra. The corner-sharing octahedral tilt angles are 15°. There are a spread of Ba–O bond distances ranging from 2.98–3.04 Å. In the second Ba site, Ba is bonded to twelve O atoms to form BaO12 cuboctahedra that share corners with twelve BaO12 cuboctahedra, faces with six equivalent BaO12 cuboctahedra, faces with two equivalent NaO6 octahedra, and faces with six equivalent IrO6 octahedra. There are six shorter (2.98 Å) and six longer (2.99 Å) Ba–O bond lengths. Ir is bonded to six O atoms to form IrO6 octahedra that share corners with three equivalent BaO12 cuboctahedra, corners with three equivalent NaO6 octahedra, faces with seven BaO12 cuboctahedra, and a faceface with one IrO6 octahedra. The corner-sharing octahedral tilt angles are 1°. There is three shorter (1.91 Å) and three longer (2.06 Å) Ir–O bond length. There are two inequivalent O sites. In the first O site, O is bonded in a distorted linear geometry to one Na, four Ba, and one Ir atom. In the second O site, O is bonded to four Ba and two equivalent Ir atoms to form a mixture of distorted corner and face-sharing OBa4Ir2 octahedra. The corner-sharing octahedra tilt angles range from 4–60°.