data_[K4Sr2Nb2Se8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  K  0.8200  2.2000  1.5200
  Sr  0.9500  2.0000  1.3200
  Nb  1.6000  1.4500  0.8200
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [I-4]
_cell_length_a [7.8271]
_cell_length_b [7.8271]
_cell_length_c [9.6131]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [82]
_chemical_formula_structural [K2SrNbSe4]
_chemical_formula_sum '[K4 Sr2 Nb2 Se8]'
_cell_volume [588.9398]
_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
[
  K  K0  2  0.0000  0.0000  0.0000  1
  K  K1  2  0.0000  0.5000  0.7500  1
  Sr  Sr2  2  0.0000  0.5000  0.2500  1
  Nb  Nb3  2  0.0000  0.0000  0.5000  1
  Se  Se4  8  0.1884  0.2079  0.3785  1
]