data_Na2Hf
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.68
_cell_length_b   5.68
_cell_length_c   2.91
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2Hf
_chemical_formula_sum   'Na2 Hf1'
_cell_volume   81.38
_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  0.84  0.64  0.63  1.0
  Na  Na2  1  0.0  0.28  0.28  1.0
  Hf  Hf0  1  0.0  0.0  0.0  1.0

data_Na2Hf
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.91
_cell_length_b   5.68
_cell_length_c   5.68
_cell_angle_alpha   120.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2Hf
_chemical_formula_sum   'Na2 Hf1'
_cell_volume   81.38
_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  0.28  0.0  0.28  1.0
  Na  Na1  1  0.63  0.84  0.64  1.0
  Hf  Hf2  1  0.0  0.0  0.0  1.0

Na Na Hf
Na Na Hf 0 2 + + + 1 2 o o o 