data_Nb2Hg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.37
_cell_length_b   5.37
_cell_length_c   4.92
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   54.58
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Nb2Hg
_chemical_formula_sum   'Nb4 Hg2'
_cell_volume   115.51
_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
  Nb  Nb2  1  0.04  0.84  0.23  1.0
  Nb  Nb3  1  0.49  0.84  0.23  1.0
  Nb  Nb4  1  0.04  0.16  0.69  1.0
  Nb  Nb5  1  0.49  0.16  0.69  1.0
  Hg  Hg0  1  0.77  0.31  0.23  1.0
  Hg  Hg1  1  0.77  0.69  0.69  1.0

data_Nb2Hg
_symmetry_space_group_name_H-M   P-1
_cell_length_a   4.92
_cell_length_b   4.92
_cell_length_c   5.37
_cell_angle_alpha   90.0
_cell_angle_beta   117.29
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   Nb2Hg
_chemical_formula_sum   'Nb4 Hg2'
_cell_volume   115.51
_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
  Nb  Nb0  2  0.16  0.23  0.38  1.0
  Nb  Nb1  2  0.16  0.23  0.94  1.0
  Hg  Hg2  2  0.31  0.77  0.81  1.0

Nb Nb Nb Nb Hg Hg