data_Na2NbAg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.11
_cell_length_b   5.11
_cell_length_c   3.62
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2NbAg
_chemical_formula_sum   'Na2 Nb1 Ag1'
_cell_volume   94.26
_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  0.55  0.0  0.81  1.0
  Na  Na2  1  0.0  0.55  0.81  1.0
  Nb  Nb3  1  0.0  0.0  0.0  1.0
  Ag  Ag0  1  0.55  0.55  0.0  1.0

data_Na2NbAg
_symmetry_space_group_name_H-M   Cm
_cell_length_a   7.22
_cell_length_b   7.22
_cell_length_c   3.62
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Na2NbAg
_chemical_formula_sum   'Na4 Nb2 Ag2'
_cell_volume   188.51
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  4  0.28  0.28  0.81  1.0
  Nb  Nb1  2  0.0  0.0  0.0  1.0
  Ag  Ag2  2  0.05  0.5  0.0  1.0

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