data_[K2Se2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  K  0.8200  2.2000  1.5200
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Immm]
_cell_length_a [2.9726]
_cell_length_b [6.0075]
_cell_length_c [6.6464]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [71]
_chemical_formula_structural [KSe]
_chemical_formula_sum '[K2 Se2]'
_cell_volume [118.6934]
_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
  Se  Se1  2  0.0000  0.0000  0.5000  1
]