data_NaCa2Nb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.34
_cell_length_b   6.34
_cell_length_c   6.34
_cell_angle_alpha   135.49
_cell_angle_beta   135.49
_cell_angle_gamma   64.77
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaCa2Nb
_chemical_formula_sum   'Na1 Ca2 Nb1'
_cell_volume   123.34
_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  Na2  1  0.0  0.0  0.0  1.0
  Ca  Ca0  1  0.0  0.0  0.35  1.0
  Ca  Ca1  1  0.0  0.4  0.68  1.0
  Nb  Nb3  1  0.4  0.0  0.68  1.0

data_NaCa2Nb
_symmetry_space_group_name_H-M   P1
_cell_length_a   4.8
_cell_length_b   4.8
_cell_length_c   6.34
_cell_angle_alpha   112.26
_cell_angle_beta   112.26
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaCa2Nb
_chemical_formula_sum   'Na1 Ca2 Nb1'
_cell_volume   123.34
_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  0.0  1.0
  Ca  Ca1  1  0.28  0.68  0.28  1.0
  Ca  Ca2  1  0.35  0.35  0.35  1.0
  Nb  Nb3  1  0.68  0.28  0.28  1.0

Na Ca Ca Nb