data_[Mg2Hg2Se4]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Mg  1.3100  1.5000  0.8600
  Hg  2.0000  1.5000  1.2450
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [P1]
_cell_length_a [4.1026]
_cell_length_b [6.7801]
_cell_length_c [8.2504]
_cell_angle_alpha [88.6722]
_cell_angle_beta [76.8535]
_cell_angle_gamma [86.2419]
_symmetry_Int_Tables_number [1]
_chemical_formula_structural [MgHgSe2]
_chemical_formula_sum '[Mg2 Hg2 Se4]'
_cell_volume [222.9874]
_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
[
  Mg  Mg0  1  0.5311  0.1563  0.7820  1.0
  Mg  Mg1  1  0.8754  0.6349  0.0720  1.0
  Hg  Hg2  1  0.2291  0.7029  0.5678  1.0
  Hg  Hg3  1  0.4096  0.1744  0.3055  1.0
  Se  Se4  1  0.0196  0.9082  0.8477  1.0
  Se  Se5  1  0.1164  0.3261  0.6017  1.0
  Se  Se6  1  0.4163  0.3995  0.0420  1.0
  Se  Se7  1  0.7529  0.8399  0.3469  1.0
]