The structure described by Ho5Ti5O17 crystallizes in the orthorhombic Pmn2_1 space group. There are five inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 7-coordinate geometry to one O(4), one O(5), one O(6), two equivalent O(13), and two equivalent O(14) atoms. In the second Ho site, Ho(2) is bonded in a 10-coordinate geometry to one O(17), one O(2), two equivalent O(1), two equivalent O(10), two equivalent O(7), and two equivalent O(8) atoms. In the third Ho site, Ho(3) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), two equivalent O(12), and two equivalent O(9) atoms. In the fourth Ho site, Ho(4) is bonded in a 7-coordinate geometry to one O(13), one O(14), one O(17), two equivalent O(4), and two equivalent O(5) atoms. In the fifth Ho site, Ho(5) is bonded in a 8-coordinate geometry to one O(3), one O(6), two equivalent O(11), two equivalent O(15), and two equivalent O(16) atoms. There are five inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(10), one O(7), one O(8), one O(9), and two equivalent O(1) atoms to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 14-38°. In the second Ti site, Ti(2) is bonded to one O(10), one O(11), one O(12), one O(9), and two equivalent O(2) atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 16-40°. In the third Ti site, Ti(3) is bonded to one O(11), one O(12), one O(15), one O(16), and two equivalent O(3) atoms to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 11-40°. In the fourth Ti site, Ti(4) is bonded to one O(13), one O(14), one O(15), one O(16), and two equivalent O(6) atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 11-30°. In the fifth Ti site, Ti(5) is bonded to one O(4), one O(5), one O(7), one O(8), and two equivalent O(17) atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 14-38°. There are seventeen inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Ho(3), two equivalent Ho(2), and two equivalent Ti(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ho(2), one Ho(3), and two equivalent Ti(2) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ho(3), one Ho(5), and two equivalent Ti(3) atoms. In the fourth O site, O(4) is bonded to one Ho(1), two equivalent Ho(4), and one Ti(5) atom to form OHo3Ti tetrahedra that share  a cornercorner with one O(8)Ho2Ti2 tetrahedra, corners with two equivalent O(4)Ho3Ti tetrahedra, corners with four equivalent O(14)Ho3Ti tetrahedra, corners with two equivalent O(5)Ho3Ti trigonal pyramids, edges with two equivalent O(13)Ho3Ti tetrahedra, and edges with two equivalent O(5)Ho3Ti trigonal pyramids. In the fifth O site, O(5) is bonded to one Ho(1), two equivalent Ho(4), and one Ti(5) atom to form distorted OHo3Ti trigonal pyramids that share  a cornercorner with one O(8)Ho2Ti2 tetrahedra, corners with two equivalent O(4)Ho3Ti tetrahedra, corners with four equivalent O(13)Ho3Ti tetrahedra, corners with two equivalent O(5)Ho3Ti trigonal pyramids, edges with two equivalent O(14)Ho3Ti tetrahedra, and edges with two equivalent O(4)Ho3Ti tetrahedra. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ho(1), one Ho(5), and two equivalent Ti(4) atoms. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to two equivalent Ho(2), one Ti(1), and one Ti(5) atom. In the eighth O site, O(8) is bonded to two equivalent Ho(2), one Ti(1), and one Ti(5) atom to form distorted OHo2Ti2 tetrahedra that share  a cornercorner with one O(4)Ho3Ti tetrahedra, corners with two equivalent O(8)Ho2Ti2 tetrahedra, and  a cornercorner with one O(5)Ho3Ti trigonal pyramid. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to two equivalent Ho(3), one Ti(1), and one Ti(2) atom. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to two equivalent Ho(2), one Ti(1), and one Ti(2) atom. In the eleventh O site, O(11) is bonded to two equivalent Ho(5), one Ti(2), and one Ti(3) atom to form distorted corner-sharing OHo2Ti2 tetrahedra. In the twelfth O site, O(12) is bonded to two equivalent Ho(3), one Ti(2), and one Ti(3) atom to form distorted corner-sharing OHo2Ti2 tetrahedra. In the thirteenth O site, O(13) is bonded to one Ho(4), two equivalent Ho(1), and one Ti(4) atom to form a mixture of distorted edge and corner-sharing OHo3Ti tetrahedra. In the fourteenth O site, O(14) is bonded to one Ho(4), two equivalent Ho(1), and one Ti(4) atom to form a mixture of edge and corner-sharing OHo3Ti tetrahedra. In the fifteenth O site, O(15) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ho(5), one Ti(3), and one Ti(4) atom. In the sixteenth O site, O(16) is bonded in a 4-coordinate geometry to two equivalent Ho(5), one Ti(3), and one Ti(4) atom. In the seventeenth O site, O(17) is bonded in a 4-coordinate geometry to one Ho(2), one Ho(4), and two equivalent Ti(5) atoms. is represented by the CIF file [CIF]
data_Ho5Ti5O17
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.833
_cell_length_b   5.451
_cell_length_c   31.749
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   663.405
_cell_formula_units_Z   2
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  0.000  0.178  0.018  1.0
  Ho  Ho1  1  0.000  0.736  0.699  1.0
  Ho  Ho2  1  0.000  0.270  0.793  1.0
  Ho  Ho3  1  0.000  0.323  0.570  1.0
  Ho  Ho4  1  0.000  0.796  0.891  1.0
  Ho  Ho5  1  0.500  0.264  0.199  1.0
  Ho  Ho6  1  0.500  0.822  0.518  1.0
  Ho  Ho7  1  0.500  0.730  0.293  1.0
  Ho  Ho8  1  0.500  0.677  0.070  1.0
  Ho  Ho9  1  0.500  0.204  0.391  1.0
  Ti  Ti10  1  0.000  0.754  0.206  1.0
  Ti  Ti11  1  0.000  0.257  0.297  1.0
  Ti  Ti12  1  0.000  0.758  0.382  1.0
  Ti  Ti13  1  0.000  0.283  0.469  1.0
  Ti  Ti14  1  0.500  0.774  0.619  1.0
  Ti  Ti15  1  0.500  0.246  0.706  1.0
  Ti  Ti16  1  0.500  0.743  0.797  1.0
  Ti  Ti17  1  0.500  0.242  0.882  1.0
  Ti  Ti18  1  0.500  0.717  0.969  1.0
  Ti  Ti19  1  0.000  0.226  0.119  1.0
  O  O20  1  0.000  0.198  0.717  1.0
  O  O21  1  0.000  0.695  0.797  1.0
  O  O22  1  0.000  0.207  0.871  1.0
  O  O23  1  0.000  0.453  0.070  1.0
  O  O24  1  0.000  0.959  0.082  1.0
  O  O25  1  0.000  0.755  0.964  1.0
  O  O26  1  0.000  0.546  0.161  1.0
  O  O27  1  0.000  0.073  0.177  1.0
  O  O28  1  0.000  0.960  0.267  1.0
  O  O29  1  0.000  0.453  0.242  1.0
  O  O30  1  0.500  0.888  0.851  1.0
  O  O31  1  0.500  0.397  0.825  1.0
  O  O32  1  0.500  0.449  0.008  1.0
  O  O33  1  0.500  0.947  0.018  1.0
  O  O34  1  0.500  0.017  0.928  1.0
  O  O35  1  0.500  0.537  0.913  1.0
  O  O36  1  0.500  0.273  0.127  1.0
  O  O37  1  0.500  0.802  0.217  1.0
  O  O38  1  0.500  0.305  0.297  1.0
  O  O39  1  0.500  0.793  0.371  1.0
  O  O40  1  0.500  0.245  0.464  1.0
  O  O41  1  0.500  0.547  0.570  1.0
  O  O42  1  0.500  0.041  0.582  1.0
  O  O43  1  0.500  0.454  0.661  1.0
  O  O44  1  0.500  0.927  0.677  1.0
  O  O45  1  0.500  0.547  0.742  1.0
  O  O46  1  0.500  0.040  0.767  1.0
  O  O47  1  0.000  0.112  0.351  1.0
  O  O48  1  0.000  0.603  0.325  1.0
  O  O49  1  0.000  0.983  0.428  1.0
  O  O50  1  0.000  0.463  0.413  1.0
  O  O51  1  0.000  0.551  0.508  1.0
  O  O52  1  0.000  0.053  0.518  1.0
  O  O53  1  0.000  0.727  0.627  1.0
[/CIF]
.
The structure described by Ho5Ti5O17 crystallizes in the orthorhombic Pmn2_1 space group. There are five inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 7-coordinate geometry to one O(4), one O(5), one O(6), two equivalent O(13), and two equivalent O(14) atoms. In the second Ho site, Ho(2) is bonded in a 10-coordinate geometry to one O(17), one O(2), two equivalent O(1), two equivalent O(10), two equivalent O(7), and two equivalent O(8) atoms. In the third Ho site, Ho(3) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), two equivalent O(12), and two equivalent O(9) atoms. In the fourth Ho site, Ho(4) is bonded in a 7-coordinate geometry to one O(13), one O(14), one O(17), two equivalent O(4), and two equivalent O(5) atoms. In the fifth Ho site, Ho(5) is bonded in a 8-coordinate geometry to one O(3), one O(6), two equivalent O(11), two equivalent O(15), and two equivalent O(16) atoms. There are five inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(10), one O(7), one O(8), one O(9), and two equivalent O(1) atoms to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 14-38°. In the second Ti site, Ti(2) is bonded to one O(10), one O(11), one O(12), one O(9), and two equivalent O(2) atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 16-40°. In the third Ti site, Ti(3) is bonded to one O(11), one O(12), one O(15), one O(16), and two equivalent O(3) atoms to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 11-40°. In the fourth Ti site, Ti(4) is bonded to one O(13), one O(14), one O(15), one O(16), and two equivalent O(6) atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 11-30°. In the fifth Ti site, Ti(5) is bonded to one O(4), one O(5), one O(7), one O(8), and two equivalent O(17) atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 14-38°. There are seventeen inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Ho(3), two equivalent Ho(2), and two equivalent Ti(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ho(2), one Ho(3), and two equivalent Ti(2) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ho(3), one Ho(5), and two equivalent Ti(3) atoms. In the fourth O site, O(4) is bonded to one Ho(1), two equivalent Ho(4), and one Ti(5) atom to form OHo3Ti tetrahedra that share  a cornercorner with one O(8)Ho2Ti2 tetrahedra, corners with two equivalent O(4)Ho3Ti tetrahedra, corners with four equivalent O(14)Ho3Ti tetrahedra, corners with two equivalent O(5)Ho3Ti trigonal pyramids, edges with two equivalent O(13)Ho3Ti tetrahedra, and edges with two equivalent O(5)Ho3Ti trigonal pyramids. In the fifth O site, O(5) is bonded to one Ho(1), two equivalent Ho(4), and one Ti(5) atom to form distorted OHo3Ti trigonal pyramids that share  a cornercorner with one O(8)Ho2Ti2 tetrahedra, corners with two equivalent O(4)Ho3Ti tetrahedra, corners with four equivalent O(13)Ho3Ti tetrahedra, corners with two equivalent O(5)Ho3Ti trigonal pyramids, edges with two equivalent O(14)Ho3Ti tetrahedra, and edges with two equivalent O(4)Ho3Ti tetrahedra. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ho(1), one Ho(5), and two equivalent Ti(4) atoms. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to two equivalent Ho(2), one Ti(1), and one Ti(5) atom. In the eighth O site, O(8) is bonded to two equivalent Ho(2), one Ti(1), and one Ti(5) atom to form distorted OHo2Ti2 tetrahedra that share  a cornercorner with one O(4)Ho3Ti tetrahedra, corners with two equivalent O(8)Ho2Ti2 tetrahedra, and  a cornercorner with one O(5)Ho3Ti trigonal pyramid. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to two equivalent Ho(3), one Ti(1), and one Ti(2) atom. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to two equivalent Ho(2), one Ti(1), and one Ti(2) atom. In the eleventh O site, O(11) is bonded to two equivalent Ho(5), one Ti(2), and one Ti(3) atom to form distorted corner-sharing OHo2Ti2 tetrahedra. In the twelfth O site, O(12) is bonded to two equivalent Ho(3), one Ti(2), and one Ti(3) atom to form distorted corner-sharing OHo2Ti2 tetrahedra. In the thirteenth O site, O(13) is bonded to one Ho(4), two equivalent Ho(1), and one Ti(4) atom to form a mixture of distorted edge and corner-sharing OHo3Ti tetrahedra. In the fourteenth O site, O(14) is bonded to one Ho(4), two equivalent Ho(1), and one Ti(4) atom to form a mixture of edge and corner-sharing OHo3Ti tetrahedra. In the fifteenth O site, O(15) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ho(5), one Ti(3), and one Ti(4) atom. In the sixteenth O site, O(16) is bonded in a 4-coordinate geometry to two equivalent Ho(5), one Ti(3), and one Ti(4) atom. In the seventeenth O site, O(17) is bonded in a 4-coordinate geometry to one Ho(2), one Ho(4), and two equivalent Ti(5) atoms. is represented by the CIF file [CIF]
data_Ho5Ti5O17
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.833
_cell_length_b   5.451
_cell_length_c   31.749
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   663.405
_cell_formula_units_Z   2
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  0.000  0.178  0.018  1.0
  Ho  Ho1  1  0.000  0.736  0.699  1.0
  Ho  Ho2  1  0.000  0.270  0.793  1.0
  Ho  Ho3  1  0.000  0.323  0.570  1.0
  Ho  Ho4  1  0.000  0.796  0.891  1.0
  Ho  Ho5  1  0.500  0.264  0.199  1.0
  Ho  Ho6  1  0.500  0.822  0.518  1.0
  Ho  Ho7  1  0.500  0.730  0.293  1.0
  Ho  Ho8  1  0.500  0.677  0.070  1.0
  Ho  Ho9  1  0.500  0.204  0.391  1.0
  Ti  Ti10  1  0.000  0.754  0.206  1.0
  Ti  Ti11  1  0.000  0.257  0.297  1.0
  Ti  Ti12  1  0.000  0.758  0.382  1.0
  Ti  Ti13  1  0.000  0.283  0.469  1.0
  Ti  Ti14  1  0.500  0.774  0.619  1.0
  Ti  Ti15  1  0.500  0.246  0.706  1.0
  Ti  Ti16  1  0.500  0.743  0.797  1.0
  Ti  Ti17  1  0.500  0.242  0.882  1.0
  Ti  Ti18  1  0.500  0.717  0.969  1.0
  Ti  Ti19  1  0.000  0.226  0.119  1.0
  O  O20  1  0.000  0.198  0.717  1.0
  O  O21  1  0.000  0.695  0.797  1.0
  O  O22  1  0.000  0.207  0.871  1.0
  O  O23  1  0.000  0.453  0.070  1.0
  O  O24  1  0.000  0.959  0.082  1.0
  O  O25  1  0.000  0.755  0.964  1.0
  O  O26  1  0.000  0.546  0.161  1.0
  O  O27  1  0.000  0.073  0.177  1.0
  O  O28  1  0.000  0.960  0.267  1.0
  O  O29  1  0.000  0.453  0.242  1.0
  O  O30  1  0.500  0.888  0.851  1.0
  O  O31  1  0.500  0.397  0.825  1.0
  O  O32  1  0.500  0.449  0.008  1.0
  O  O33  1  0.500  0.947  0.018  1.0
  O  O34  1  0.500  0.017  0.928  1.0
  O  O35  1  0.500  0.537  0.913  1.0
  O  O36  1  0.500  0.273  0.127  1.0
  O  O37  1  0.500  0.802  0.217  1.0
  O  O38  1  0.500  0.305  0.297  1.0
  O  O39  1  0.500  0.793  0.371  1.0
  O  O40  1  0.500  0.245  0.464  1.0
  O  O41  1  0.500  0.547  0.570  1.0
  O  O42  1  0.500  0.041  0.582  1.0
  O  O43  1  0.500  0.454  0.661  1.0
  O  O44  1  0.500  0.927  0.677  1.0
  O  O45  1  0.500  0.547  0.742  1.0
  O  O46  1  0.500  0.040  0.767  1.0
  O  O47  1  0.000  0.112  0.351  1.0
  O  O48  1  0.000  0.603  0.325  1.0
  O  O49  1  0.000  0.983  0.428  1.0
  O  O50  1  0.000  0.463  0.413  1.0
  O  O51  1  0.000  0.551  0.508  1.0
  O  O52  1  0.000  0.053  0.518  1.0
  O  O53  1  0.000  0.727  0.627  1.0
[/CIF]
.