data_[Ni3Sn18Hg3]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Ni  1.9100  1.3500  0.7400
  Sn  1.9600  1.4500  0.8300
  Hg  2.0000  1.5000  1.2450
]
_symmetry_space_group_name_H-M [R-3]
_cell_length_a [6.6680]
_cell_length_b [6.6680]
_cell_length_c [16.3942]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [148]
_chemical_formula_structural [NiSn6Hg]
_chemical_formula_sum '[Ni3 Sn18 Hg3]'
_cell_volume [631.2766]
_cell_formula_units_Z [3]
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
[
  Ni  Ni0  3  0.0000  0.0000  0.0000  1.0
  Sn  Sn1  18  0.0362  0.4325  0.4122  1.0
  Hg  Hg2  3  -0.0000  0.0000  0.5000  1.0
]