data_[K6Ni12Se18]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  K  0.8200  2.2000  1.5200
  Ni  1.9100  1.3500  0.7400
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [R-3m]
_cell_length_a [7.0856]
_cell_length_b [7.0856]
_cell_length_c [19.8515]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [166]
_chemical_formula_structural [KNi2Se3]
_chemical_formula_sum '[K6 Ni12 Se18]'
_cell_volume [863.1299]
_cell_formula_units_Z [6]
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  6  0.0000  0.0000  0.1980  1.0
  Ni  Ni1  9  0.0000  0.5000  0.0000  1.0
  Ni  Ni2  3  0.0000  0.0000  0.0000  1.0
  Se  Se3  18  0.0107  0.5053  0.2739  1.0
]