data_Na2NbAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.11
_cell_length_b   3.11
_cell_length_c   10.09
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   108.03
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2NbAs
_chemical_formula_sum   'Na2 Nb1 As1'
_cell_volume   92.6
_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  0.83  0.0  0.42  1.0
  Na  Na2  1  0.0  0.0  0.31  1.0
  Nb  Nb3  1  0.83  0.0  0.59  1.0
  As  As0  1  0.0  0.0  0.81  1.0

data_Na2NbAs
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.11
_cell_length_b   3.11
_cell_length_c   10.09
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   108.03
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2NbAs
_chemical_formula_sum   'Na2 Nb1 As1'
_cell_volume   92.6
_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  0.0  0.0  0.31  1.0
  Na  Na1  1  0.83  0.0  0.42  1.0
  Nb  Nb2  1  0.83  0.0  0.59  1.0
  As  As3  1  0.0  0.0  0.81  1.0

Na Na Nb As
Na Na Nb As 0 1 + o o 0 2 o o o 2 3 + o o 