Ho2O3 crystallizes in the trigonal P-3m1 space group. Ho(1) is bonded in a 7-coordinate geometry to three equivalent O(2) and four equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Ho(1) atoms to form OHo4 tetrahedra that share corners with six equivalent O(2)Ho6 octahedra, corners with six equivalent O(1)Ho4 tetrahedra, edges with three equivalent O(2)Ho6 octahedra, and edges with three equivalent O(1)Ho4 tetrahedra. The corner-sharing octahedral tilt angles range from 19-55°. In the second O site, O(2) is bonded to six equivalent Ho(1) atoms to form OHo6 octahedra that share corners with twelve equivalent O(1)Ho4 tetrahedra, edges with six equivalent O(2)Ho6 octahedra, and edges with six equivalent O(1)Ho4 tetrahedra.
Ho2O3 crystallizes in the trigonal P-3m1 space group. Ho(1) is bonded in a 7-coordinate geometry to three equivalent O(2) and four equivalent O(1) atoms. All Ho(1)-O(2) bond lengths are 2.55 Å. There are three shorter (2.18 Å) and one longer (2.30 Å) Ho(1)-O(1) bond length. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Ho(1) atoms to form OHo4 tetrahedra that share corners with six equivalent O(2)Ho6 octahedra, corners with six equivalent O(1)Ho4 tetrahedra, edges with three equivalent O(2)Ho6 octahedra, and edges with three equivalent O(1)Ho4 tetrahedra. The corner-sharing octahedral tilt angles range from 19-55°. In the second O site, O(2) is bonded to six equivalent Ho(1) atoms to form OHo6 octahedra that share corners with twelve equivalent O(1)Ho4 tetrahedra, edges with six equivalent O(2)Ho6 octahedra, and edges with six equivalent O(1)Ho4 tetrahedra.