Materials Data on Ho2O3 by Materials Project

Ho2O3 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Ho3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ho–O bond distances ranging from 2.20–2.57 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Ho3+ atoms to form OHo4 tetrahedra that share corners with six equivalent OHo6 octahedra, corners with six equivalent OHo4 tetrahedra, edges with three equivalent OHo6 octahedra, and edges with three equivalent OHo4 tetrahedra. The corner-sharing octahedra tilt angles range from 19–55°. In the second O2- site, O2- is bonded to six equivalent Ho3+ atoms to form OHo6 octahedra that share corners with twelve equivalent OHo4 tetrahedra, edges with six equivalent OHo6 octahedra, and edges with six equivalent OHo4 tetrahedra.