The material structure described by Gd2SiO5 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 9-coordinate geometry to one O(5), two equivalent O(1), three equivalent O(2), and three equivalent O(4) atoms. In the second Gd site, Gd(2) is bonded to one O(1), three equivalent O(3), and three equivalent O(5) atoms to form distorted GdO7 hexagonal pyramids that share corners with two equivalent Si(1)O4 tetrahedra, edges with six equivalent Gd(2)O7 hexagonal pyramids, and  an edgeedge with one Si(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with two equivalent Gd(2)O7 hexagonal pyramids and  an edgeedge with one Gd(2)O7 hexagonal pyramid. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Gd(2), two equivalent Gd(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to three equivalent Gd(1) and one Si(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to three equivalent Gd(2) and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to three equivalent Gd(1) and one Si(1) atom. In the fifth O site, O(5) is bonded to one Gd(1) and three equivalent Gd(2) atoms to form a mixture of corner and edge-sharing OGd4 tetrahedra. is represented by the CIF card [CIF]
data_Gd2SiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.047
_cell_length_b   6.745
_cell_length_c   9.139
_cell_angle_alpha   72.551
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   414.376
_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
  Gd  Gd0  1  0.854  0.416  0.886  1.0
  Gd  Gd1  1  0.354  0.084  0.114  1.0
  Gd  Gd2  1  0.146  0.584  0.114  1.0
  Gd  Gd3  1  0.646  0.916  0.886  1.0
  Gd  Gd4  1  0.376  0.234  0.474  1.0
  Gd  Gd5  1  0.876  0.266  0.526  1.0
  Gd  Gd6  1  0.624  0.766  0.526  1.0
  Gd  Gd7  1  0.124  0.734  0.474  1.0
  Si  Si8  1  0.413  0.460  0.798  1.0
  Si  Si9  1  0.913  0.040  0.202  1.0
  Si  Si10  1  0.587  0.540  0.202  1.0
  Si  Si11  1  0.087  0.960  0.798  1.0
  O  O12  1  0.569  0.643  0.795  1.0
  O  O13  1  0.069  0.857  0.205  1.0
  O  O14  1  0.431  0.357  0.205  1.0
  O  O15  1  0.931  0.143  0.795  1.0
  O  O16  1  0.542  0.253  0.865  1.0
  O  O17  1  0.042  0.247  0.135  1.0
  O  O18  1  0.458  0.747  0.135  1.0
  O  O19  1  0.958  0.753  0.865  1.0
  O  O20  1  0.362  0.507  0.615  1.0
  O  O21  1  0.862  0.993  0.385  1.0
  O  O22  1  0.638  0.493  0.385  1.0
  O  O23  1  0.138  0.007  0.615  1.0
  O  O24  1  0.231  0.448  0.905  1.0
  O  O25  1  0.731  0.052  0.095  1.0
  O  O26  1  0.769  0.552  0.095  1.0
  O  O27  1  0.269  0.948  0.905  1.0
  O  O28  1  0.620  0.051  0.617  1.0
  O  O29  1  0.120  0.449  0.383  1.0
  O  O30  1  0.380  0.949  0.383  1.0
  O  O31  1  0.880  0.551  0.617  1.0
[/CIF]
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The material structure described by Gd2SiO5 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 9-coordinate geometry to one O(5), two equivalent O(1), three equivalent O(2), and three equivalent O(4) atoms. In the second Gd site, Gd(2) is bonded to one O(1), three equivalent O(3), and three equivalent O(5) atoms to form distorted GdO7 hexagonal pyramids that share corners with two equivalent Si(1)O4 tetrahedra, edges with six equivalent Gd(2)O7 hexagonal pyramids, and  an edgeedge with one Si(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with two equivalent Gd(2)O7 hexagonal pyramids and  an edgeedge with one Gd(2)O7 hexagonal pyramid. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Gd(2), two equivalent Gd(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to three equivalent Gd(1) and one Si(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to three equivalent Gd(2) and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to three equivalent Gd(1) and one Si(1) atom. In the fifth O site, O(5) is bonded to one Gd(1) and three equivalent Gd(2) atoms to form a mixture of corner and edge-sharing OGd4 tetrahedra. is represented by the CIF card [CIF]
data_Gd2SiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.047
_cell_length_b   6.745
_cell_length_c   9.139
_cell_angle_alpha   72.551
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   414.376
_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
  Gd  Gd0  1  0.854  0.416  0.886  1.0
  Gd  Gd1  1  0.354  0.084  0.114  1.0
  Gd  Gd2  1  0.146  0.584  0.114  1.0
  Gd  Gd3  1  0.646  0.916  0.886  1.0
  Gd  Gd4  1  0.376  0.234  0.474  1.0
  Gd  Gd5  1  0.876  0.266  0.526  1.0
  Gd  Gd6  1  0.624  0.766  0.526  1.0
  Gd  Gd7  1  0.124  0.734  0.474  1.0
  Si  Si8  1  0.413  0.460  0.798  1.0
  Si  Si9  1  0.913  0.040  0.202  1.0
  Si  Si10  1  0.587  0.540  0.202  1.0
  Si  Si11  1  0.087  0.960  0.798  1.0
  O  O12  1  0.569  0.643  0.795  1.0
  O  O13  1  0.069  0.857  0.205  1.0
  O  O14  1  0.431  0.357  0.205  1.0
  O  O15  1  0.931  0.143  0.795  1.0
  O  O16  1  0.542  0.253  0.865  1.0
  O  O17  1  0.042  0.247  0.135  1.0
  O  O18  1  0.458  0.747  0.135  1.0
  O  O19  1  0.958  0.753  0.865  1.0
  O  O20  1  0.362  0.507  0.615  1.0
  O  O21  1  0.862  0.993  0.385  1.0
  O  O22  1  0.638  0.493  0.385  1.0
  O  O23  1  0.138  0.007  0.615  1.0
  O  O24  1  0.231  0.448  0.905  1.0
  O  O25  1  0.731  0.052  0.095  1.0
  O  O26  1  0.769  0.552  0.095  1.0
  O  O27  1  0.269  0.948  0.905  1.0
  O  O28  1  0.620  0.051  0.617  1.0
  O  O29  1  0.120  0.449  0.383  1.0
  O  O30  1  0.380  0.949  0.383  1.0
  O  O31  1  0.880  0.551  0.617  1.0
[/CIF]
.