Materials Data on BaSrHf2O6 by Materials Project
BaSrHf2O6 crystallizes in the tetragonal I-42m space group. The structure is three-dimensional. Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with twelve equivalent BaO12 cuboctahedra, faces with six equivalent SrO12 cuboctahedra, and faces with eight equivalent HfO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.80–3.11 Å. Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with twelve equivalent SrO12 cuboctahedra, faces with six equivalent BaO12 cuboctahedra, and faces with eight equivalent HfO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.78–3.14 Å. Hf4+ is bonded to six O2- atoms to form HfO6 octahedra that share corners with six equivalent HfO6 octahedra, faces with four equivalent BaO12 cuboctahedra, and faces with four equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–13°. All Hf–O bond lengths are 2.09 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ba2+, two equivalent Sr2+, and two equivalent Hf4+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to two equivalent Ba2+, two equivalent Sr2+, and two equivalent Hf4+ atoms.