data_[Sm4Cu8Se12]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Sm  1.1700  1.8500  1.2290
  Cu  1.9000  1.3500  0.8200
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Cmcm]
_cell_length_a [8.6313]
_cell_length_b [12.4716]
_cell_length_c [4.8992]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [63]
_chemical_formula_structural [SmCu2Se3]
_chemical_formula_sum '[Sm4 Cu8 Se12]'
_cell_volume [527.3791]
_cell_formula_units_Z [4]
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
[
  Sm  Sm0  4  0.0000  0.2653  0.7500  1
  Cu  Cu1  8  0.1942  0.0000  0.0000  1
  Se  Se2  8  0.1938  0.3508  0.2500  1
  Se  Se3  4  0.0000  0.1135  0.2500  1
]