data_[Tm2Nb2Si4O16]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Tm  1.2500  1.7500  1.0950
  Nb  1.6000  1.4500  0.8200
  Si  1.9000  1.1000  0.5400
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [I-4m2]
_cell_length_a [6.7016]
_cell_length_b [6.7016]
_cell_length_c [5.9834]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [119]
_chemical_formula_structural [TmNb(SiO4)2]
_chemical_formula_sum '[Tm2 Nb2 Si4 O16]'
_cell_volume [268.7251]
_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
[
  Tm  Tm0  2  0.0000  0.5000  0.2500  1.0
  Nb  Nb1  2  0.0000  0.0000  0.0000  1.0
  Si  Si2  2  0.0000  0.0000  0.5000  1.0
  Si  Si3  2  0.0000  0.5000  0.7500  1.0
  O  O4  8  0.0000  0.1757  0.3106  1.0
  O  O5  8  0.0000  0.3079  0.9219  1.0
]