Ho2Nd2O5 crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a body-centered cubic geometry to eight equivalent O(1) atoms. In the second Ho site, Ho(2) is bonded in a square co-planar geometry to four equivalent O(2) atoms. Nd(1) is bonded in a 5-coordinate geometry to one O(2) and four equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ho(1) and two equivalent Nd(1) atoms to form ONd2Ho2 tetrahedra that share corners with two equivalent O(2)Nd2Ho4 octahedra, corners with ten equivalent O(1)Nd2Ho2 tetrahedra, and edges with five equivalent O(1)Nd2Ho2 tetrahedra. The corner-sharing octahedral tilt angles are 60°. In the second O site, O(2) is bonded to four equivalent Ho(2) and two equivalent Nd(1) atoms to form ONd2Ho4 octahedra that share corners with four equivalent O(2)Nd2Ho4 octahedra, corners with eight equivalent O(1)Nd2Ho2 tetrahedra, and edges with four equivalent O(2)Nd2Ho4 octahedra. The corner-sharing octahedra are not tilted.
Ho2Nd2O5 crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a body-centered cubic geometry to eight equivalent O(1) atoms. All Ho(1)-O(1) bond lengths are 2.37 Å. In the second Ho site, Ho(2) is bonded in a square co-planar geometry to four equivalent O(2) atoms. All Ho(2)-O(2) bond lengths are 2.73 Å. Nd(1) is bonded in a 5-coordinate geometry to one O(2) and four equivalent O(1) atoms. The Nd(1)-O(2) bond length is 3.04 Å. All Nd(1)-O(1) bond lengths are 2.23 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ho(1) and two equivalent Nd(1) atoms to form ONd2Ho2 tetrahedra that share corners with two equivalent O(2)Nd2Ho4 octahedra, corners with ten equivalent O(1)Nd2Ho2 tetrahedra, and edges with five equivalent O(1)Nd2Ho2 tetrahedra. The corner-sharing octahedral tilt angles are 60°. In the second O site, O(2) is bonded to four equivalent Ho(2) and two equivalent Nd(1) atoms to form ONd2Ho4 octahedra that share corners with four equivalent O(2)Nd2Ho4 octahedra, corners with eight equivalent O(1)Nd2Ho2 tetrahedra, and edges with four equivalent O(2)Nd2Ho4 octahedra. The corner-sharing octahedra are not tilted.