Ho2(SeO4)3 crystallizes in the trigonal R-3c space group. Ho(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form HoO6 octahedra that share corners with six equivalent Se(1)O4 tetrahedra. Se(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form SeO4 tetrahedra that share corners with four equivalent Ho(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-28°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ho(1) and one Se(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Ho(1) and one Se(1) atom.
Ho2(SeO4)3 crystallizes in the trigonal R-3c space group. Ho(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form HoO6 octahedra that share corners with six equivalent Se(1)O4 tetrahedra. All Ho(1)-O(1) bond lengths are 2.20 Å. All Ho(1)-O(2) bond lengths are 2.22 Å. Se(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form SeO4 tetrahedra that share corners with four equivalent Ho(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-28°. Both Se(1)-O(1) bond lengths are 1.64 Å. Both Se(1)-O(2) bond lengths are 1.64 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ho(1) and one Se(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Ho(1) and one Se(1) atom.