data_[Sm1Mg1Hg2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Sm  1.1700  1.8500  1.2290
  Mg  1.3100  1.5000  0.8600
  Hg  2.0000  1.5000  1.2450
]
_symmetry_space_group_name_H-M [P4/mmm]
_cell_length_a [5.1064]
_cell_length_b [5.1064]
_cell_length_c [3.8086]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [123]
_chemical_formula_structural [SmMgHg2]
_chemical_formula_sum '[Sm1 Mg1 Hg2]'
_cell_volume [99.3100]
_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
[
  Sm  Sm0  1  0.5000  0.5000  0.5000  1
  Mg  Mg1  1  0.0000  0.0000  0.5000  1
  Hg  Hg2  2  0.0000  0.5000  0.0000  1
]