The compound described by Ca2Gd3Si3O13 crystallizes in the hexagonal P6_3/m space group. Ca(1) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(2), and three equivalent O(3) atoms. Gd(1) is bonded to one O(1), one O(3), one O(4), and four equivalent O(2) atoms to form distorted GdO7 pentagonal bipyramids that share corners with six equivalent Gd(1)O7 pentagonal bipyramids, corners with four equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Si(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with four equivalent Gd(1)O7 pentagonal bipyramids and  an edgeedge with one Gd(1)O7 pentagonal bipyramid. There are four inequivalent O sites. In the first O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Gd(1), and one Si(1) atom. In the second O site, O(4) is bonded in a trigonal planar geometry to three equivalent Gd(1) atoms. In the third O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Gd(1), and one Si(1) atom. In the fourth O site, O(2) is bonded in a 1-coordinate geometry to one Ca(1), two equivalent Gd(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_Ca2Gd3Si3O13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.957
_cell_length_b   9.517
_cell_length_c   9.517
_cell_angle_alpha   120.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   545.651
_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
  Ca  Ca0  1  0.004  0.667  0.333  1.0
  Ca  Ca1  1  0.996  0.333  0.667  1.0
  Ca  Ca2  1  0.504  0.333  0.667  1.0
  Ca  Ca3  1  0.496  0.667  0.333  1.0
  Gd  Gd4  1  0.750  0.752  0.993  1.0
  Gd  Gd5  1  0.250  0.248  0.007  1.0
  Gd  Gd6  1  0.750  0.241  0.248  1.0
  Gd  Gd7  1  0.250  0.759  0.752  1.0
  Gd  Gd8  1  0.750  0.007  0.759  1.0
  Gd  Gd9  1  0.250  0.993  0.241  1.0
  Si  Si10  1  0.750  0.974  0.369  1.0
  Si  Si11  1  0.250  0.026  0.631  1.0
  Si  Si12  1  0.750  0.395  0.026  1.0
  Si  Si13  1  0.250  0.605  0.974  1.0
  Si  Si14  1  0.750  0.631  0.605  1.0
  Si  Si15  1  0.250  0.369  0.395  1.0
  O  O16  1  0.750  0.880  0.474  1.0
  O  O17  1  0.250  0.120  0.526  1.0
  O  O18  1  0.750  0.594  0.120  1.0
  O  O19  1  0.250  0.406  0.880  1.0
  O  O20  1  0.750  0.526  0.406  1.0
  O  O21  1  0.250  0.474  0.594  1.0
  O  O22  1  0.935  0.910  0.244  1.0
  O  O23  1  0.065  0.090  0.756  1.0
  O  O24  1  0.935  0.334  0.090  1.0
  O  O25  1  0.435  0.090  0.756  1.0
  O  O26  1  0.065  0.666  0.910  1.0
  O  O27  1  0.565  0.910  0.244  1.0
  O  O28  1  0.935  0.756  0.666  1.0
  O  O29  1  0.435  0.666  0.910  1.0
  O  O30  1  0.065  0.244  0.334  1.0
  O  O31  1  0.565  0.334  0.090  1.0
  O  O32  1  0.435  0.244  0.334  1.0
  O  O33  1  0.565  0.756  0.666  1.0
  O  O34  1  0.750  0.521  0.691  1.0
  O  O35  1  0.250  0.479  0.309  1.0
  O  O36  1  0.750  0.171  0.479  1.0
  O  O37  1  0.250  0.829  0.521  1.0
  O  O38  1  0.750  0.309  0.829  1.0
  O  O39  1  0.250  0.691  0.171  1.0
  O  O40  1  0.750  0.000  0.000  1.0
  O  O41  1  0.250  0.000  0.000  1.0
[/CIF]
.
The compound described by Ca2Gd3Si3O13 crystallizes in the hexagonal P6_3/m space group. Ca(1) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(2), and three equivalent O(3) atoms. Gd(1) is bonded to one O(1), one O(3), one O(4), and four equivalent O(2) atoms to form distorted GdO7 pentagonal bipyramids that share corners with six equivalent Gd(1)O7 pentagonal bipyramids, corners with four equivalent Si(1)O4 tetrahedra, and  an edgeedge with one Si(1)O4 tetrahedra. Si(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with four equivalent Gd(1)O7 pentagonal bipyramids and  an edgeedge with one Gd(1)O7 pentagonal bipyramid. There are four inequivalent O sites. In the first O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Gd(1), and one Si(1) atom. In the second O site, O(4) is bonded in a trigonal planar geometry to three equivalent Gd(1) atoms. In the third O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Gd(1), and one Si(1) atom. In the fourth O site, O(2) is bonded in a 1-coordinate geometry to one Ca(1), two equivalent Gd(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_Ca2Gd3Si3O13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.957
_cell_length_b   9.517
_cell_length_c   9.517
_cell_angle_alpha   120.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   545.651
_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
  Ca  Ca0  1  0.004  0.667  0.333  1.0
  Ca  Ca1  1  0.996  0.333  0.667  1.0
  Ca  Ca2  1  0.504  0.333  0.667  1.0
  Ca  Ca3  1  0.496  0.667  0.333  1.0
  Gd  Gd4  1  0.750  0.752  0.993  1.0
  Gd  Gd5  1  0.250  0.248  0.007  1.0
  Gd  Gd6  1  0.750  0.241  0.248  1.0
  Gd  Gd7  1  0.250  0.759  0.752  1.0
  Gd  Gd8  1  0.750  0.007  0.759  1.0
  Gd  Gd9  1  0.250  0.993  0.241  1.0
  Si  Si10  1  0.750  0.974  0.369  1.0
  Si  Si11  1  0.250  0.026  0.631  1.0
  Si  Si12  1  0.750  0.395  0.026  1.0
  Si  Si13  1  0.250  0.605  0.974  1.0
  Si  Si14  1  0.750  0.631  0.605  1.0
  Si  Si15  1  0.250  0.369  0.395  1.0
  O  O16  1  0.750  0.880  0.474  1.0
  O  O17  1  0.250  0.120  0.526  1.0
  O  O18  1  0.750  0.594  0.120  1.0
  O  O19  1  0.250  0.406  0.880  1.0
  O  O20  1  0.750  0.526  0.406  1.0
  O  O21  1  0.250  0.474  0.594  1.0
  O  O22  1  0.935  0.910  0.244  1.0
  O  O23  1  0.065  0.090  0.756  1.0
  O  O24  1  0.935  0.334  0.090  1.0
  O  O25  1  0.435  0.090  0.756  1.0
  O  O26  1  0.065  0.666  0.910  1.0
  O  O27  1  0.565  0.910  0.244  1.0
  O  O28  1  0.935  0.756  0.666  1.0
  O  O29  1  0.435  0.666  0.910  1.0
  O  O30  1  0.065  0.244  0.334  1.0
  O  O31  1  0.565  0.334  0.090  1.0
  O  O32  1  0.435  0.244  0.334  1.0
  O  O33  1  0.565  0.756  0.666  1.0
  O  O34  1  0.750  0.521  0.691  1.0
  O  O35  1  0.250  0.479  0.309  1.0
  O  O36  1  0.750  0.171  0.479  1.0
  O  O37  1  0.250  0.829  0.521  1.0
  O  O38  1  0.750  0.309  0.829  1.0
  O  O39  1  0.250  0.691  0.171  1.0
  O  O40  1  0.750  0.000  0.000  1.0
  O  O41  1  0.250  0.000  0.000  1.0
[/CIF]
.