The crystal structure described by Gd3Si2O6Cl5 crystallizes in the monoclinic C2/m space group. There are two inequivalent Gd sites. In the first Gd site, Gd(1) is bonded to one O(2), one O(4), one Cl(2), one Cl(4), and three equivalent Cl(1) atoms to form distorted GdCl5O2 pentagonal bipyramids that share corners with four equivalent Gd(1)Cl5O2 pentagonal bipyramids, corners with two equivalent Si(1)O4 tetrahedra,  an edgeedge with one Gd(2)Cl2O6 hexagonal bipyramid, and edges with two equivalent Gd(1)Cl5O2 pentagonal bipyramids. In the second Gd site, Gd(2) is bonded to two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent Cl(3) atoms to form distorted GdCl2O6 hexagonal bipyramids that share corners with four equivalent Gd(2)Cl2O6 hexagonal bipyramids, edges with two equivalent Gd(1)Cl5O2 pentagonal bipyramids, and edges with four equivalent 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(1)Cl5O2 pentagonal bipyramids, corners with two equivalent Si(1)O4 tetrahedra, and edges with two equivalent Gd(2)Cl2O6 hexagonal bipyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Gd(1), one Gd(2), and one Si(1) atom. In the third O site, O(3) is bonded in a linear geometry to two equivalent Gd(2) and two equivalent Si(1) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Gd(1), one Gd(2), and one Si(1) atom. There are four inequivalent Cl sites. In the first Cl site, Cl(1) is bonded in a distorted trigonal planar geometry to three equivalent Gd(1) atoms. In the second Cl site, Cl(2) is bonded in a bent 150 degrees geometry to two equivalent Gd(1) atoms. In the third Cl site, Cl(3) is bonded in a bent 150 degrees geometry to two equivalent Gd(2) atoms. In the fourth Cl site, Cl(4) is bonded in a bent 150 degrees geometry to two equivalent Gd(1) atoms. is represented by the CIF card [CIF]
data_Gd3Si2Cl5O6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.522
_cell_length_b   7.522
_cell_length_c   11.875
_cell_angle_alpha   80.728
_cell_angle_beta   80.728
_cell_angle_gamma   89.090
_symmetry_Int_Tables_number   1
_cell_volume   654.416
_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
  Gd  Gd0  1  0.584  0.081  0.669  1.0
  Gd  Gd1  1  0.000  0.500  0.000  1.0
  Gd  Gd2  1  0.416  0.919  0.331  1.0
  Gd  Gd3  1  0.919  0.416  0.331  1.0
  Gd  Gd4  1  0.500  0.000  0.000  1.0
  Gd  Gd5  1  0.081  0.584  0.669  1.0
  Si  Si6  1  0.110  0.819  0.143  1.0
  Si  Si7  1  0.181  0.890  0.857  1.0
  Si  Si8  1  0.819  0.110  0.143  1.0
  Si  Si9  1  0.890  0.181  0.857  1.0
  Cl  Cl10  1  0.115  0.674  0.421  1.0
  Cl  Cl11  1  0.621  0.621  0.356  1.0
  Cl  Cl12  1  0.326  0.885  0.579  1.0
  Cl  Cl13  1  0.316  0.316  0.996  1.0
  Cl  Cl14  1  0.379  0.379  0.644  1.0
  Cl  Cl15  1  0.885  0.326  0.579  1.0
  Cl  Cl16  1  0.674  0.115  0.421  1.0
  Cl  Cl17  1  0.223  0.223  0.337  1.0
  Cl  Cl18  1  0.684  0.684  0.004  1.0
  Cl  Cl19  1  0.777  0.777  0.663  1.0
  O  O20  1  0.953  0.953  0.191  1.0
  O  O21  1  0.957  0.390  0.828  1.0
  O  O22  1  0.855  0.145  0.000  1.0
  O  O23  1  0.390  0.957  0.828  1.0
  O  O24  1  0.130  0.695  0.828  1.0
  O  O25  1  0.305  0.870  0.172  1.0
  O  O26  1  0.870  0.305  0.172  1.0
  O  O27  1  0.145  0.855  0.000  1.0
  O  O28  1  0.695  0.130  0.828  1.0
  O  O29  1  0.047  0.047  0.809  1.0
  O  O30  1  0.043  0.610  0.172  1.0
  O  O31  1  0.610  0.043  0.172  1.0
[/CIF]
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The crystal structure described by Gd3Si2O6Cl5 crystallizes in the monoclinic C2/m space group. There are two inequivalent Gd sites. In the first Gd site, Gd(1) is bonded to one O(2), one O(4), one Cl(2), one Cl(4), and three equivalent Cl(1) atoms to form distorted GdCl5O2 pentagonal bipyramids that share corners with four equivalent Gd(1)Cl5O2 pentagonal bipyramids, corners with two equivalent Si(1)O4 tetrahedra,  an edgeedge with one Gd(2)Cl2O6 hexagonal bipyramid, and edges with two equivalent Gd(1)Cl5O2 pentagonal bipyramids. In the second Gd site, Gd(2) is bonded to two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent Cl(3) atoms to form distorted GdCl2O6 hexagonal bipyramids that share corners with four equivalent Gd(2)Cl2O6 hexagonal bipyramids, edges with two equivalent Gd(1)Cl5O2 pentagonal bipyramids, and edges with four equivalent 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(1)Cl5O2 pentagonal bipyramids, corners with two equivalent Si(1)O4 tetrahedra, and edges with two equivalent Gd(2)Cl2O6 hexagonal bipyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Gd(1), one Gd(2), and one Si(1) atom. In the third O site, O(3) is bonded in a linear geometry to two equivalent Gd(2) and two equivalent Si(1) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Gd(1), one Gd(2), and one Si(1) atom. There are four inequivalent Cl sites. In the first Cl site, Cl(1) is bonded in a distorted trigonal planar geometry to three equivalent Gd(1) atoms. In the second Cl site, Cl(2) is bonded in a bent 150 degrees geometry to two equivalent Gd(1) atoms. In the third Cl site, Cl(3) is bonded in a bent 150 degrees geometry to two equivalent Gd(2) atoms. In the fourth Cl site, Cl(4) is bonded in a bent 150 degrees geometry to two equivalent Gd(1) atoms. is represented by the CIF card [CIF]
data_Gd3Si2Cl5O6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.522
_cell_length_b   7.522
_cell_length_c   11.875
_cell_angle_alpha   80.728
_cell_angle_beta   80.728
_cell_angle_gamma   89.090
_symmetry_Int_Tables_number   1
_cell_volume   654.416
_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
  Gd  Gd0  1  0.584  0.081  0.669  1.0
  Gd  Gd1  1  0.000  0.500  0.000  1.0
  Gd  Gd2  1  0.416  0.919  0.331  1.0
  Gd  Gd3  1  0.919  0.416  0.331  1.0
  Gd  Gd4  1  0.500  0.000  0.000  1.0
  Gd  Gd5  1  0.081  0.584  0.669  1.0
  Si  Si6  1  0.110  0.819  0.143  1.0
  Si  Si7  1  0.181  0.890  0.857  1.0
  Si  Si8  1  0.819  0.110  0.143  1.0
  Si  Si9  1  0.890  0.181  0.857  1.0
  Cl  Cl10  1  0.115  0.674  0.421  1.0
  Cl  Cl11  1  0.621  0.621  0.356  1.0
  Cl  Cl12  1  0.326  0.885  0.579  1.0
  Cl  Cl13  1  0.316  0.316  0.996  1.0
  Cl  Cl14  1  0.379  0.379  0.644  1.0
  Cl  Cl15  1  0.885  0.326  0.579  1.0
  Cl  Cl16  1  0.674  0.115  0.421  1.0
  Cl  Cl17  1  0.223  0.223  0.337  1.0
  Cl  Cl18  1  0.684  0.684  0.004  1.0
  Cl  Cl19  1  0.777  0.777  0.663  1.0
  O  O20  1  0.953  0.953  0.191  1.0
  O  O21  1  0.957  0.390  0.828  1.0
  O  O22  1  0.855  0.145  0.000  1.0
  O  O23  1  0.390  0.957  0.828  1.0
  O  O24  1  0.130  0.695  0.828  1.0
  O  O25  1  0.305  0.870  0.172  1.0
  O  O26  1  0.870  0.305  0.172  1.0
  O  O27  1  0.145  0.855  0.000  1.0
  O  O28  1  0.695  0.130  0.828  1.0
  O  O29  1  0.047  0.047  0.809  1.0
  O  O30  1  0.043  0.610  0.172  1.0
  O  O31  1  0.610  0.043  0.172  1.0
[/CIF]
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