data_K2MgHg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.14
_cell_length_b   4.78
_cell_length_c   8.14
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   K2MgHg
_chemical_formula_sum   'K2 Mg1 Hg1'
_cell_volume   161.13
_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
  K  K1  1  0.07  0.39  0.99  1.0
  K  K2  1  0.07  0.39  0.15  1.0
  Mg  Mg3  1  0.0  0.0  0.0  1.0
  Hg  Hg0  1  0.0  0.0  0.07  1.0

data_K2MgHg
_symmetry_space_group_name_H-M   P1
_cell_length_a   4.14
_cell_length_b   4.78
_cell_length_c   8.14
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   K2MgHg
_chemical_formula_sum   'K2 Mg1 Hg1'
_cell_volume   161.13
_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
  K  K0  1  0.07  0.39  0.15  1.0
  K  K1  1  0.07  0.39  0.99  1.0
  Mg  Mg2  1  0.0  0.0  0.0  1.0
  Hg  Hg3  1  0.0  0.0  0.07  1.0

K K Mg Hg
K K Mg Hg 0 1 o o + 2 3 o o o 