data_HgC2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.48
_cell_length_b   5.18
_cell_length_c   3.59
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HgC2
_chemical_formula_sum   'Hg2 C4'
_cell_volume   83.36
_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
  Hg  Hg4  1  0.0  0.0  0.0  1.0
  Hg  Hg5  1  0.24  0.59  0.8  1.0
  C  C0  1  0.44  0.06  0.0  1.0
  C  C1  1  0.04  0.12  0.0  1.0
  C  C2  1  0.67  0.71  0.8  1.0
  C  C3  1  0.8  0.47  0.8  1.0

data_HgC2
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.59
_cell_length_b   4.48
_cell_length_c   5.18
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HgC2
_chemical_formula_sum   'Hg2 C4'
_cell_volume   83.36
_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
  Hg  Hg0  1  0.0  0.0  0.0  1.0
  Hg  Hg1  1  0.8  0.24  0.59  1.0
  C  C2  1  0.0  0.04  0.12  1.0
  C  C3  1  0.0  0.44  0.06  1.0
  C  C4  1  0.8  0.67  0.71  1.0
  C  C5  1  0.8  0.8  0.47  1.0

Hg Hg C C C C