Materials Data on Ba5Ho2ZrAl2O13 by Materials Project

Abstract

Ba5Ho2ZrAl2O13 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are three inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form distorted BaO12 cuboctahedra that share corners with six equivalent BaO12 cuboctahedra, faces with three equivalent BaO12 cuboctahedra, faces with three equivalent ZrO6 octahedra, faces with four equivalent HoO6 octahedra, and a faceface with one AlO4 tetrahedra. There are a spread of Ba–O bond distances ranging from 2.95–3.37 Å. In the second Ba2+ site, Ba2+ is bonded in a distorted q6 geometry to nine O2- atoms. There are three shorter (2.78 Å) and six longer (3.06 Å) Ba–O bond lengths. In the third Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. All Ba–O bond lengths are 2.93 Å. Ho3+ is bonded to six O2- atoms to form HoO6 octahedra that share corners with three equivalent ZrO6 octahedra, corners with three equivalent AlO4 tetrahedra, and faces with four equivalent BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.23 Å) and three longer (2.27 Å) Ho–O bond lengths. Zr4+ is bonded to six equivalent O2- atoms to form ZrO6 octahedra that share corners with six equivalent HoO6 octahedra and faces with six equivalent BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. All Zr–O bond lengths are 2.12 Å. Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with three equivalent HoO6 octahedra, a cornercorner with one AlO4 tetrahedra, and a faceface with one BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 19°. There is one shorter (1.73 Å) and three longer (1.78 Å) Al–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four Ba2+, one Ho3+, and one Zr4+ atom to form a mixture of distorted edge, corner, and face-sharing OBa4HoZr octahedra. The corner-sharing octahedra tilt angles range from 0–60°. In the second O2- site, O2- is bonded in a linear geometry to two equivalent Al3+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to four Ba2+, one Ho3+, and one Al3+ atom.