data_Ca2Hg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.07
_cell_length_b   9.07
_cell_length_c   5.68
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   155.38
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca2Hg
_chemical_formula_sum   'Ca4 Hg2'
_cell_volume   194.38
_cell_formula_units_Z   2
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
  Ca  Ca0  1  0.93  0.15  0.26  1.0
  Ca  Ca1  1  0.93  0.31  0.26  1.0
  Ca  Ca2  1  0.93  0.85  0.42  1.0
  Ca  Ca3  1  0.93  0.69  0.42  1.0
  Hg  Hg4  1  0.93  0.51  0.26  1.0
  Hg  Hg5  1  0.93  0.49  0.42  1.0

data_Ca2Hg
_symmetry_space_group_name_H-M   P-1
_cell_length_a   3.87
_cell_length_b   5.68
_cell_length_c   9.07
_cell_angle_alpha   90.0
_cell_angle_beta   102.31
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   Ca2Hg
_chemical_formula_sum   'Ca4 Hg2'
_cell_volume   194.38
_cell_formula_units_Z   2
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
  Ca  Ca0  2  0.15  0.58  0.15  1.0
  Ca  Ca1  2  0.31  0.58  0.31  1.0
  Hg  Hg2  2  0.49  0.42  0.49  1.0

Ca Ca Ca Ca Hg Hg
Ca Ca Ca Ca Hg Hg 0 1 o o o 1 4 o o o 2 3 o o o 3 5 o o o 4 5 o o o 