data_Na2LiNb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.8
_cell_length_b   2.8
_cell_length_c   11.49
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2LiNb
_chemical_formula_sum   'Na2 Li1 Nb1'
_cell_volume   90.17
_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  0.4  0.4  0.88  1.0
  Na  Na2  1  0.4  0.4  0.61  1.0
  Li  Li0  1  0.0  0.0  0.0  1.0
  Nb  Nb3  1  0.0  0.0  0.75  1.0

data_Na2LiNb
_symmetry_space_group_name_H-M   Cm
_cell_length_a   3.96
_cell_length_b   3.96
_cell_length_c   11.49
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Na2LiNb
_chemical_formula_sum   'Na4 Li2 Nb2'
_cell_volume   180.35
_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  2  0.4  0.0  0.61  1.0
  Na  Na1  2  0.4  0.0  0.88  1.0
  Li  Li2  2  0.0  0.0  0.0  1.0
  Nb  Nb3  2  0.0  0.0  0.75  1.0

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