data_[Rb4Fe4Se6]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Rb  0.8200  2.3500  1.6600
  Fe  1.8300  1.4000  0.8525
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Cm]
_cell_length_a [3.5087]
_cell_length_b [23.6970]
_cell_length_c [18.0888]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [8]
_chemical_formula_structural [Rb2Fe2Se3]
_chemical_formula_sum '[Rb4 Fe4 Se6]'
_cell_volume [1503.9973]
_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
[
  Rb  Rb0  4  0.3436  0.1474  0.4140  1
  Fe  Fe1  4  0.3761  0.4521  0.5275  1
  Se  Se2  4  0.3770  0.0978  0.5847  1
  Se  Se3  2  0.3767  0.0000  0.4476  1
]