data_Na2NbBr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.71
_cell_length_b   6.71
_cell_length_c   6.71
_cell_angle_alpha   152.36
_cell_angle_beta   130.64
_cell_angle_gamma   57.51
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2NbBr
_chemical_formula_sum   'Na2 Nb1 Br1'
_cell_volume   105.91
_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
  Na  Na1  1  0.6  0.0  0.41  1.0
  Na  Na2  1  0.0  0.0  0.64  1.0
  Nb  Nb3  1  0.6  0.0  0.36  1.0
  Br  Br0  1  0.0  0.0  0.25  1.0

data_Na2NbBr
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.21
_cell_length_b   5.61
_cell_length_c   6.71
_cell_angle_alpha   114.68
_cell_angle_beta   103.82
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2NbBr
_chemical_formula_sum   'Na2 Nb1 Br1'
_cell_volume   105.91
_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
  Na  Na0  1  0.19  0.59  0.19  1.0
  Na  Na1  1  0.36  0.36  0.36  1.0
  Nb  Nb2  1  0.24  0.64  0.24  1.0
  Br  Br3  1  0.75  0.75  0.75  1.0

Na Na Nb Br
Na Na Nb Br 0 2 o o o 0 1 + o o 0 3 + o o 0 3 o o o 1 2 - o o 1 3 o + + 1 3 o o o 2 3 + o o 2 3 o o o 3 3 o + + 