The structure described by Tb5Si3O13 crystallizes in the hexagonal P6_3/m space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(4), and four equivalent O(2) atoms. In the second Tb site, Tb(2) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(2), and three equivalent O(3) atoms. Si(1) is bonded in a tetrahedral geometry to one O(1), one O(3), and two equivalent O(2) atoms. There are four inequivalent O sites. In the first O site, O(3) is bonded to one Tb(1), two equivalent Tb(2), and one Si(1) atom to form distorted edge-sharing OTb3Si tetrahedra. In the second O site, O(4) is bonded in a trigonal planar geometry to three equivalent Tb(1) atoms. In the third O site, O(1) is bonded in a 4-coordinate geometry to one Tb(1), two equivalent Tb(2), and one Si(1) atom. In the fourth O site, O(2) is bonded in a 3-coordinate geometry to one Tb(2), two equivalent Tb(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_Tb5Si3O13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.511
_cell_length_b   9.511
_cell_length_c   6.840
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   535.827
_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
  Tb  Tb0  1  0.766  0.999  0.750  1.0
  Tb  Tb1  1  0.234  0.001  0.250  1.0
  Tb  Tb2  1  0.233  0.234  0.750  1.0
  Tb  Tb3  1  0.767  0.766  0.250  1.0
  Tb  Tb4  1  0.001  0.767  0.750  1.0
  Tb  Tb5  1  0.999  0.233  0.250  1.0
  Tb  Tb6  1  0.667  0.333  0.004  1.0
  Tb  Tb7  1  0.333  0.667  0.996  1.0
  Tb  Tb8  1  0.333  0.667  0.504  1.0
  Tb  Tb9  1  0.667  0.333  0.496  1.0
  Si  Si10  1  0.973  0.372  0.750  1.0
  Si  Si11  1  0.027  0.628  0.250  1.0
  Si  Si12  1  0.399  0.027  0.750  1.0
  Si  Si13  1  0.601  0.973  0.250  1.0
  Si  Si14  1  0.628  0.601  0.750  1.0
  Si  Si15  1  0.372  0.399  0.250  1.0
  O  O16  1  0.511  0.680  0.750  1.0
  O  O17  1  0.489  0.320  0.250  1.0
  O  O18  1  0.169  0.489  0.750  1.0
  O  O19  1  0.831  0.511  0.250  1.0
  O  O20  1  0.320  0.831  0.750  1.0
  O  O21  1  0.680  0.169  0.250  1.0
  O  O22  1  0.911  0.248  0.940  1.0
  O  O23  1  0.089  0.752  0.060  1.0
  O  O24  1  0.338  0.089  0.940  1.0
  O  O25  1  0.089  0.752  0.440  1.0
  O  O26  1  0.662  0.911  0.060  1.0
  O  O27  1  0.911  0.248  0.560  1.0
  O  O28  1  0.752  0.662  0.940  1.0
  O  O29  1  0.662  0.911  0.440  1.0
  O  O30  1  0.248  0.338  0.060  1.0
  O  O31  1  0.338  0.089  0.560  1.0
  O  O32  1  0.248  0.338  0.440  1.0
  O  O33  1  0.752  0.662  0.560  1.0
  O  O34  1  0.872  0.471  0.750  1.0
  O  O35  1  0.128  0.529  0.250  1.0
  O  O36  1  0.599  0.128  0.750  1.0
  O  O37  1  0.401  0.872  0.250  1.0
  O  O38  1  0.529  0.401  0.750  1.0
  O  O39  1  0.471  0.599  0.250  1.0
  O  O40  1  0.000  0.000  0.750  1.0
  O  O41  1  0.000  0.000  0.250  1.0
[/CIF]
.
The structure described by Tb5Si3O13 crystallizes in the hexagonal P6_3/m space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(4), and four equivalent O(2) atoms. In the second Tb site, Tb(2) is bonded in a 9-coordinate geometry to three equivalent O(1), three equivalent O(2), and three equivalent O(3) atoms. Si(1) is bonded in a tetrahedral geometry to one O(1), one O(3), and two equivalent O(2) atoms. There are four inequivalent O sites. In the first O site, O(3) is bonded to one Tb(1), two equivalent Tb(2), and one Si(1) atom to form distorted edge-sharing OTb3Si tetrahedra. In the second O site, O(4) is bonded in a trigonal planar geometry to three equivalent Tb(1) atoms. In the third O site, O(1) is bonded in a 4-coordinate geometry to one Tb(1), two equivalent Tb(2), and one Si(1) atom. In the fourth O site, O(2) is bonded in a 3-coordinate geometry to one Tb(2), two equivalent Tb(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_Tb5Si3O13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.511
_cell_length_b   9.511
_cell_length_c   6.840
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   535.827
_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
  Tb  Tb0  1  0.766  0.999  0.750  1.0
  Tb  Tb1  1  0.234  0.001  0.250  1.0
  Tb  Tb2  1  0.233  0.234  0.750  1.0
  Tb  Tb3  1  0.767  0.766  0.250  1.0
  Tb  Tb4  1  0.001  0.767  0.750  1.0
  Tb  Tb5  1  0.999  0.233  0.250  1.0
  Tb  Tb6  1  0.667  0.333  0.004  1.0
  Tb  Tb7  1  0.333  0.667  0.996  1.0
  Tb  Tb8  1  0.333  0.667  0.504  1.0
  Tb  Tb9  1  0.667  0.333  0.496  1.0
  Si  Si10  1  0.973  0.372  0.750  1.0
  Si  Si11  1  0.027  0.628  0.250  1.0
  Si  Si12  1  0.399  0.027  0.750  1.0
  Si  Si13  1  0.601  0.973  0.250  1.0
  Si  Si14  1  0.628  0.601  0.750  1.0
  Si  Si15  1  0.372  0.399  0.250  1.0
  O  O16  1  0.511  0.680  0.750  1.0
  O  O17  1  0.489  0.320  0.250  1.0
  O  O18  1  0.169  0.489  0.750  1.0
  O  O19  1  0.831  0.511  0.250  1.0
  O  O20  1  0.320  0.831  0.750  1.0
  O  O21  1  0.680  0.169  0.250  1.0
  O  O22  1  0.911  0.248  0.940  1.0
  O  O23  1  0.089  0.752  0.060  1.0
  O  O24  1  0.338  0.089  0.940  1.0
  O  O25  1  0.089  0.752  0.440  1.0
  O  O26  1  0.662  0.911  0.060  1.0
  O  O27  1  0.911  0.248  0.560  1.0
  O  O28  1  0.752  0.662  0.940  1.0
  O  O29  1  0.662  0.911  0.440  1.0
  O  O30  1  0.248  0.338  0.060  1.0
  O  O31  1  0.338  0.089  0.560  1.0
  O  O32  1  0.248  0.338  0.440  1.0
  O  O33  1  0.752  0.662  0.560  1.0
  O  O34  1  0.872  0.471  0.750  1.0
  O  O35  1  0.128  0.529  0.250  1.0
  O  O36  1  0.599  0.128  0.750  1.0
  O  O37  1  0.401  0.872  0.250  1.0
  O  O38  1  0.529  0.401  0.750  1.0
  O  O39  1  0.471  0.599  0.250  1.0
  O  O40  1  0.000  0.000  0.750  1.0
  O  O41  1  0.000  0.000  0.250  1.0
[/CIF]
.