The material structure described by Ho2SiO5 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to one O(4), three equivalent O(1), and three equivalent O(3) atoms to form distorted HoO7 hexagonal pyramids that share corners with two equivalent Si(1)O4 tetrahedra, edges with six equivalent Ho(1)O7 hexagonal pyramids, and  an edgeedge with one Si(1)O4 tetrahedra. In the second Ho site, Ho(2) is bonded in a 8-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(4), and three equivalent O(5) atoms. Si(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form SiO4 tetrahedra that share corners with two equivalent Ho(1)O7 hexagonal pyramids and  an edgeedge with one Ho(1)O7 hexagonal pyramid. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Ho(2) and three equivalent Ho(1) atoms to form a mixture of corner and edge-sharing OHo4 tetrahedra. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Ho(2) and one Si(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to three equivalent Ho(1) and one Si(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Ho(1), two equivalent Ho(2), and one Si(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to three equivalent Ho(2) and one Si(1) atom. is represented by the CIF card [CIF]
data_Ho2SiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.803
_cell_length_b   6.650
_cell_length_c   9.020
_cell_angle_alpha   74.579
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   393.352
_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  0.124  0.732  0.472  1.0
  Ho  Ho1  1  0.624  0.768  0.528  1.0
  Ho  Ho2  1  0.876  0.268  0.528  1.0
  Ho  Ho3  1  0.376  0.232  0.472  1.0
  Ho  Ho4  1  0.639  0.946  0.873  1.0
  Ho  Ho5  1  0.139  0.554  0.127  1.0
  Ho  Ho6  1  0.361  0.054  0.127  1.0
  Ho  Ho7  1  0.861  0.446  0.873  1.0
  Si  Si8  1  0.090  0.976  0.799  1.0
  Si  Si9  1  0.590  0.524  0.201  1.0
  Si  Si10  1  0.910  0.024  0.201  1.0
  Si  Si11  1  0.410  0.476  0.799  1.0
  O  O12  1  0.881  0.562  0.614  1.0
  O  O13  1  0.381  0.938  0.386  1.0
  O  O14  1  0.119  0.438  0.386  1.0
  O  O15  1  0.619  0.062  0.614  1.0
  O  O16  1  0.285  0.982  0.896  1.0
  O  O17  1  0.785  0.518  0.104  1.0
  O  O18  1  0.715  0.018  0.104  1.0
  O  O19  1  0.215  0.482  0.896  1.0
  O  O20  1  0.138  0.009  0.615  1.0
  O  O21  1  0.638  0.491  0.385  1.0
  O  O22  1  0.862  0.991  0.385  1.0
  O  O23  1  0.362  0.509  0.615  1.0
  O  O24  1  0.570  0.666  0.791  1.0
  O  O25  1  0.070  0.834  0.209  1.0
  O  O26  1  0.430  0.334  0.209  1.0
  O  O27  1  0.930  0.166  0.791  1.0
  O  O28  1  0.552  0.278  0.873  1.0
  O  O29  1  0.052  0.222  0.127  1.0
  O  O30  1  0.448  0.722  0.127  1.0
  O  O31  1  0.948  0.778  0.873  1.0
[/CIF]
.
The material structure described by Ho2SiO5 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded to one O(4), three equivalent O(1), and three equivalent O(3) atoms to form distorted HoO7 hexagonal pyramids that share corners with two equivalent Si(1)O4 tetrahedra, edges with six equivalent Ho(1)O7 hexagonal pyramids, and  an edgeedge with one Si(1)O4 tetrahedra. In the second Ho site, Ho(2) is bonded in a 8-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(4), and three equivalent O(5) atoms. Si(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form SiO4 tetrahedra that share corners with two equivalent Ho(1)O7 hexagonal pyramids and  an edgeedge with one Ho(1)O7 hexagonal pyramid. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Ho(2) and three equivalent Ho(1) atoms to form a mixture of corner and edge-sharing OHo4 tetrahedra. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Ho(2) and one Si(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to three equivalent Ho(1) and one Si(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Ho(1), two equivalent Ho(2), and one Si(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to three equivalent Ho(2) and one Si(1) atom. is represented by the CIF card [CIF]
data_Ho2SiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.803
_cell_length_b   6.650
_cell_length_c   9.020
_cell_angle_alpha   74.579
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   393.352
_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  0.124  0.732  0.472  1.0
  Ho  Ho1  1  0.624  0.768  0.528  1.0
  Ho  Ho2  1  0.876  0.268  0.528  1.0
  Ho  Ho3  1  0.376  0.232  0.472  1.0
  Ho  Ho4  1  0.639  0.946  0.873  1.0
  Ho  Ho5  1  0.139  0.554  0.127  1.0
  Ho  Ho6  1  0.361  0.054  0.127  1.0
  Ho  Ho7  1  0.861  0.446  0.873  1.0
  Si  Si8  1  0.090  0.976  0.799  1.0
  Si  Si9  1  0.590  0.524  0.201  1.0
  Si  Si10  1  0.910  0.024  0.201  1.0
  Si  Si11  1  0.410  0.476  0.799  1.0
  O  O12  1  0.881  0.562  0.614  1.0
  O  O13  1  0.381  0.938  0.386  1.0
  O  O14  1  0.119  0.438  0.386  1.0
  O  O15  1  0.619  0.062  0.614  1.0
  O  O16  1  0.285  0.982  0.896  1.0
  O  O17  1  0.785  0.518  0.104  1.0
  O  O18  1  0.715  0.018  0.104  1.0
  O  O19  1  0.215  0.482  0.896  1.0
  O  O20  1  0.138  0.009  0.615  1.0
  O  O21  1  0.638  0.491  0.385  1.0
  O  O22  1  0.862  0.991  0.385  1.0
  O  O23  1  0.362  0.509  0.615  1.0
  O  O24  1  0.570  0.666  0.791  1.0
  O  O25  1  0.070  0.834  0.209  1.0
  O  O26  1  0.430  0.334  0.209  1.0
  O  O27  1  0.930  0.166  0.791  1.0
  O  O28  1  0.552  0.278  0.873  1.0
  O  O29  1  0.052  0.222  0.127  1.0
  O  O30  1  0.448  0.722  0.127  1.0
  O  O31  1  0.948  0.778  0.873  1.0
[/CIF]
.