data_Ca3Hg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.88
_cell_length_b   6.88
_cell_length_c   6.88
_cell_angle_alpha   146.66
_cell_angle_beta   64.22
_cell_angle_gamma   126.83
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca3Hg
_chemical_formula_sum   'Ca3 Hg1'
_cell_volume   141.39
_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
  Ca  Ca0  1  0.0  0.36  0.78  1.0
  Ca  Ca1  1  0.97  0.46  0.7  1.0
  Ca  Ca2  1  0.0  0.0  0.7  1.0
  Hg  Hg3  1  0.97  0.0  0.08  1.0

data_Ca3Hg
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.94
_cell_length_b   6.15
_cell_length_c   6.88
_cell_angle_alpha   116.58
_cell_angle_beta   106.67
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca3Hg
_chemical_formula_sum   'Ca3 Hg1'
_cell_volume   141.39
_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
  Ca  Ca0  1  0.0  0.3  0.3  1.0
  Ca  Ca1  1  0.36  0.59  0.59  1.0
  Ca  Ca2  1  0.49  0.76  0.79  1.0
  Hg  Hg3  1  0.03  0.92  0.95  1.0

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