data_Na2NbCr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.27
_cell_length_b   6.27
_cell_length_c   2.91
_cell_angle_alpha   99.81
_cell_angle_beta   99.81
_cell_angle_gamma   133.26
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2NbCr
_chemical_formula_sum   'Na2 Nb1 Cr1'
_cell_volume   75.23
_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  0.62  0.88  0.31  1.0
  Na  Na2  1  0.62  0.12  0.31  1.0
  Nb  Nb3  1  0.49  0.0  0.0  1.0
  Cr  Cr0  1  0.0  0.0  0.0  1.0

data_Na2NbCr
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.91
_cell_length_b   4.56
_cell_length_c   6.27
_cell_angle_alpha   108.9
_cell_angle_beta   99.81
_cell_angle_gamma   99.79
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2NbCr
_chemical_formula_sum   'Na2 Nb1 Cr1'
_cell_volume   75.23
_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  0.88  0.49  1.0
  Na  Na1  1  0.44  0.12  0.74  1.0
  Nb  Nb2  1  0.0  0.0  0.49  1.0
  Cr  Cr3  1  0.0  0.0  0.0  1.0

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