data_[Ca2Er2Se4F2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Ca  1.0000  1.8000  1.1400
  Er  1.2400  1.7500  1.0300
  Se  2.5500  1.1500  1.0133
  F  3.9800  0.5000  0.7050
]
_symmetry_space_group_name_H-M [P4/nmm]
_cell_length_a [3.9919]
_cell_length_b [3.9919]
_cell_length_c [14.3176]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [129]
_chemical_formula_structural [CaErSe2F]
_chemical_formula_sum '[Ca2 Er2 Se4 F2]'
_cell_volume [228.1536]
_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  2  0.0000  0.5000  0.4088  1
  Er  Er1  2  0.0000  0.5000  0.8732  1
  Se  Se2  2  0.0000  0.5000  0.0897  1
  Se  Se3  2  0.0000  0.5000  0.6915  1
  F  F4  2  0.0000  0.0000  0.5000  1
]