data_K2NbSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.76
_cell_length_b   5.76
_cell_length_c   4.28
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   121.4
_symmetry_Int_Tables_number   1
_chemical_formula_structural   K2NbSe
_chemical_formula_sum   'K2 Nb1 Se1'
_cell_volume   121.03
_cell_formula_units_Z   1
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  1  0.41  0.49  0.14  1.0
  K  K1  1  0.41  0.51  0.14  1.0
  Nb  Nb2  1  0.82  0.0  0.0  1.0
  Se  Se3  1  0.0  0.0  0.0  1.0

data_K2NbSe
_symmetry_space_group_name_H-M   P1
_cell_length_a   4.28
_cell_length_b   5.64
_cell_length_c   5.76
_cell_angle_alpha   119.3
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   K2NbSe
_chemical_formula_sum   'K2 Nb1 Se1'
_cell_volume   121.03
_cell_formula_units_Z   1
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  1  0.14  0.49  0.9  1.0
  K  K1  1  0.14  0.51  0.92  1.0
  Nb  Nb2  1  0.0  0.0  0.82  1.0
  Se  Se3  1  0.0  0.0  0.0  1.0

K K Nb Se
K K Nb Se 0 1 o o o 2 3 + o o 