data_NaCaHg2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.33
_cell_length_b   5.33
_cell_length_c   3.82
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.65
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaCaHg2
_chemical_formula_sum   'Na1 Ca1 Hg2'
_cell_volume   108.48
_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  Na3  1  0.0  0.0  0.0  1.0
  Ca  Ca0  1  0.75  0.0  0.0  1.0
  Hg  Hg1  1  0.87  0.11  0.91  1.0
  Hg  Hg2  1  0.87  0.89  0.91  1.0

data_NaCaHg2
_symmetry_space_group_name_H-M   Pm
_cell_length_a   3.82
_cell_length_b   5.33
_cell_length_c   5.33
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   6
_chemical_formula_structural   NaCaHg2
_chemical_formula_sum   'Na1 Ca1 Hg2'
_cell_volume   108.49
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '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  0.0  0.0  0.75  1.0
  Hg  Hg2  2  0.91  0.11  0.87  1.0

Na Ca Hg Hg
Na Ca Hg Hg 0 3 - - - 0 2 - o - 1 3 o - - 1 2 o o - 