data_HgAs3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.45
_cell_length_b   4.56
_cell_length_c   7.06
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HgAs3
_chemical_formula_sum   'Hg1 As3'
_cell_volume   111.15
_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
  Hg  Hg3  1  0.73  0.28  0.21  1.0
  As  As0  1  0.73  0.0  0.31  1.0
  As  As1  1  0.0  0.0  0.45  1.0
  As  As2  1  0.0  0.28  0.87  1.0

data_HgAs3
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.45
_cell_length_b   4.56
_cell_length_c   7.06
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HgAs3
_chemical_formula_sum   'Hg1 As3'
_cell_volume   111.15
_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
  Hg  Hg0  1  0.73  0.28  0.21  1.0
  As  As1  1  -0.0  0.28  0.87  1.0
  As  As2  1  0.0  0.0  0.45  1.0
  As  As3  1  0.73  0.0  0.31  1.0

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