data_[K4Ca2Se2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  K  0.8200  2.2000  1.5200
  Ca  1.0000  1.8000  1.1400
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [I4/mmm]
_cell_length_a [4.7241]
_cell_length_b [4.7241]
_cell_length_c [12.8876]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [139]
_chemical_formula_structural [K2CaSe]
_chemical_formula_sum '[K4 Ca2 Se2]'
_cell_volume [287.6184]
_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  4  0.0000  0.5000  0.2500  1
  Ca  Ca1  2  0.0000  0.0000  0.5000  1
  Se  Se2  2  0.0000  0.0000  0.0000  1
]