The structure described by Ho2TiO5 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to one O(3), two equivalent O(1), and three equivalent O(4) atoms to form distorted HoO6 octahedra that share corners with two equivalent Ho(2)O6 octahedra, corners with four equivalent Ti(1)O6 octahedra, edges with two equivalent Ho(2)O6 octahedra, and edges with four equivalent Ho(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-65°. In the second Ho site, Ho(2) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form HoO6 octahedra that share corners with two equivalent Ho(1)O6 octahedra, corners with two equivalent Ho(2)O6 octahedra, corners with four equivalent Ti(1)O6 octahedra, edges with two equivalent Ho(1)O6 octahedra, and edges with two equivalent Ho(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-65°. Ti(1) is bonded to one O(3), one O(4), one O(5), and three equivalent O(2) atoms to form distorted TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with four equivalent Ho(1)O6 octahedra, corners with four equivalent Ho(2)O6 octahedra, and edges with two equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-65°. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ho(1) and two equivalent Ho(2) atoms to form OHo4 tetrahedra that share corners with two equivalent O(3)Ho3Ti tetrahedra, corners with four equivalent O(4)Ho3Ti tetrahedra, corners with four equivalent O(1)Ho4 tetrahedra,  an edgeedge with one O(4)Ho3Ti tetrahedra, and edges with two equivalent O(3)Ho3Ti tetrahedra. In the second O site, O(2) is bonded in a 3-coordinate geometry to three equivalent Ti(1) atoms. In the third O site, O(3) is bonded to one Ho(1), two equivalent Ho(2), and one Ti(1) atom to form OHo3Ti tetrahedra that share corners with two equivalent O(3)Ho3Ti tetrahedra, corners with two equivalent O(1)Ho4 tetrahedra, corners with four equivalent O(4)Ho3Ti tetrahedra, and edges with two equivalent O(1)Ho4 tetrahedra. In the fourth O site, O(4) is bonded to three equivalent Ho(1) and one Ti(1) atom to form OHo3Ti tetrahedra that share corners with two equivalent O(4)Ho3Ti tetrahedra, corners with four equivalent O(3)Ho3Ti tetrahedra, corners with four equivalent O(1)Ho4 tetrahedra,  an edgeedge with one O(1)Ho4 tetrahedra, and edges with two equivalent O(4)Ho3Ti tetrahedra. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Ho(2) and one Ti(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ho2TiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.623
_cell_length_b   7.451
_cell_length_c   15.467
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   417.445
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Ho  Ho0  1  0.250  0.100  0.084  1.0
  Ho  Ho1  1  0.250  0.161  0.737  1.0
  Ho  Ho2  1  0.750  0.339  0.237  1.0
  Ho  Ho3  1  0.750  0.400  0.584  1.0
  Ho  Ho4  1  0.250  0.600  0.416  1.0
  Ho  Ho5  1  0.250  0.661  0.763  1.0
  Ho  Ho6  1  0.750  0.839  0.263  1.0
  Ho  Ho7  1  0.750  0.900  0.916  1.0
  Ti  Ti8  1  0.250  0.113  0.424  1.0
  Ti  Ti9  1  0.750  0.387  0.924  1.0
  Ti  Ti10  1  0.250  0.613  0.076  1.0
  Ti  Ti11  1  0.750  0.887  0.576  1.0
  O  O12  1  0.750  0.070  0.174  1.0
  O  O13  1  0.750  0.073  0.453  1.0
  O  O14  1  0.750  0.121  0.648  1.0
  O  O15  1  0.750  0.158  0.995  1.0
  O  O16  1  0.250  0.247  0.323  1.0
  O  O17  1  0.750  0.253  0.823  1.0
  O  O18  1  0.250  0.342  0.495  1.0
  O  O19  1  0.250  0.379  0.148  1.0
  O  O20  1  0.250  0.427  0.953  1.0
  O  O21  1  0.250  0.430  0.674  1.0
  O  O22  1  0.750  0.570  0.326  1.0
  O  O23  1  0.750  0.573  0.047  1.0
  O  O24  1  0.750  0.621  0.852  1.0
  O  O25  1  0.750  0.658  0.505  1.0
  O  O26  1  0.250  0.747  0.177  1.0
  O  O27  1  0.750  0.753  0.677  1.0
  O  O28  1  0.250  0.842  0.005  1.0
  O  O29  1  0.250  0.879  0.352  1.0
  O  O30  1  0.250  0.927  0.547  1.0
  O  O31  1  0.250  0.930  0.826  1.0
[/CIF]
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The structure described by Ho2TiO5 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to one O(3), two equivalent O(1), and three equivalent O(4) atoms to form distorted HoO6 octahedra that share corners with two equivalent Ho(2)O6 octahedra, corners with four equivalent Ti(1)O6 octahedra, edges with two equivalent Ho(2)O6 octahedra, and edges with four equivalent Ho(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-65°. In the second Ho site, Ho(2) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form HoO6 octahedra that share corners with two equivalent Ho(1)O6 octahedra, corners with two equivalent Ho(2)O6 octahedra, corners with four equivalent Ti(1)O6 octahedra, edges with two equivalent Ho(1)O6 octahedra, and edges with two equivalent Ho(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-65°. Ti(1) is bonded to one O(3), one O(4), one O(5), and three equivalent O(2) atoms to form distorted TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with four equivalent Ho(1)O6 octahedra, corners with four equivalent Ho(2)O6 octahedra, and edges with two equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-65°. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ho(1) and two equivalent Ho(2) atoms to form OHo4 tetrahedra that share corners with two equivalent O(3)Ho3Ti tetrahedra, corners with four equivalent O(4)Ho3Ti tetrahedra, corners with four equivalent O(1)Ho4 tetrahedra,  an edgeedge with one O(4)Ho3Ti tetrahedra, and edges with two equivalent O(3)Ho3Ti tetrahedra. In the second O site, O(2) is bonded in a 3-coordinate geometry to three equivalent Ti(1) atoms. In the third O site, O(3) is bonded to one Ho(1), two equivalent Ho(2), and one Ti(1) atom to form OHo3Ti tetrahedra that share corners with two equivalent O(3)Ho3Ti tetrahedra, corners with two equivalent O(1)Ho4 tetrahedra, corners with four equivalent O(4)Ho3Ti tetrahedra, and edges with two equivalent O(1)Ho4 tetrahedra. In the fourth O site, O(4) is bonded to three equivalent Ho(1) and one Ti(1) atom to form OHo3Ti tetrahedra that share corners with two equivalent O(4)Ho3Ti tetrahedra, corners with four equivalent O(3)Ho3Ti tetrahedra, corners with four equivalent O(1)Ho4 tetrahedra,  an edgeedge with one O(1)Ho4 tetrahedra, and edges with two equivalent O(4)Ho3Ti tetrahedra. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Ho(2) and one Ti(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ho2TiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.623
_cell_length_b   7.451
_cell_length_c   15.467
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   417.445
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Ho  Ho0  1  0.250  0.100  0.084  1.0
  Ho  Ho1  1  0.250  0.161  0.737  1.0
  Ho  Ho2  1  0.750  0.339  0.237  1.0
  Ho  Ho3  1  0.750  0.400  0.584  1.0
  Ho  Ho4  1  0.250  0.600  0.416  1.0
  Ho  Ho5  1  0.250  0.661  0.763  1.0
  Ho  Ho6  1  0.750  0.839  0.263  1.0
  Ho  Ho7  1  0.750  0.900  0.916  1.0
  Ti  Ti8  1  0.250  0.113  0.424  1.0
  Ti  Ti9  1  0.750  0.387  0.924  1.0
  Ti  Ti10  1  0.250  0.613  0.076  1.0
  Ti  Ti11  1  0.750  0.887  0.576  1.0
  O  O12  1  0.750  0.070  0.174  1.0
  O  O13  1  0.750  0.073  0.453  1.0
  O  O14  1  0.750  0.121  0.648  1.0
  O  O15  1  0.750  0.158  0.995  1.0
  O  O16  1  0.250  0.247  0.323  1.0
  O  O17  1  0.750  0.253  0.823  1.0
  O  O18  1  0.250  0.342  0.495  1.0
  O  O19  1  0.250  0.379  0.148  1.0
  O  O20  1  0.250  0.427  0.953  1.0
  O  O21  1  0.250  0.430  0.674  1.0
  O  O22  1  0.750  0.570  0.326  1.0
  O  O23  1  0.750  0.573  0.047  1.0
  O  O24  1  0.750  0.621  0.852  1.0
  O  O25  1  0.750  0.658  0.505  1.0
  O  O26  1  0.250  0.747  0.177  1.0
  O  O27  1  0.750  0.753  0.677  1.0
  O  O28  1  0.250  0.842  0.005  1.0
  O  O29  1  0.250  0.879  0.352  1.0
  O  O30  1  0.250  0.927  0.547  1.0
  O  O31  1  0.250  0.930  0.826  1.0
[/CIF]
.