data_[Er2Ti2Se6]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Er  1.2400  1.7500  1.0300
  Ti  1.5400  1.4000  0.8517
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Amm2]
_cell_length_a [18.6275]
_cell_length_b [3.7607]
_cell_length_c [13.2606]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [38]
_chemical_formula_structural [ErTiSe3]
_chemical_formula_sum '[Er2 Ti2 Se6]'
_cell_volume [928.9338]
_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
[
  Er  Er0  2  0.5000  0.0000  0.9351  1
  Ti  Ti1  2  0.5000  0.0000  0.6438  1
  Se  Se2  4  0.4026  0.0000  0.5243  1
  Se  Se3  2  0.5000  0.0000  0.2700  1
]