data_[Rb2Ca2Be2Se4]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Rb  0.8200  2.3500  1.6600
  Ca  1.0000  1.8000  1.1400
  Be  1.5700  1.0500  0.5900
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [P2/c]
_cell_length_a [7.9052]
_cell_length_b [4.8299]
_cell_length_c [8.4694]
_cell_angle_alpha [90.0000]
_cell_angle_beta [100.9111]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [13]
_chemical_formula_structural [RbCaBeSe2]
_chemical_formula_sum '[Rb2 Ca2 Be2 Se4]'
_cell_volume [317.5206]
_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  2  0.5000  0.2158  0.2500  1
  Ca  Ca1  2  0.0000  0.4882  0.7500  1
  Be  Be2  2  0.0000  0.0000  0.0000  1
  Se  Se3  4  0.2158  0.2625  0.5346  1
]