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 [Pmn2_1]
_cell_length_a [4.3556]
_cell_length_b [8.6530]
_cell_length_c [6.1383]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [31]
_chemical_formula_structural [MgHgSe2]
_chemical_formula_sum '[Mg2 Hg2 Se4]'
_cell_volume [231.3498]
_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  2  0.0000  0.1225  0.3601  1.0
  Hg  Hg1  2  0.0000  0.6348  0.3568  1.0
  Se  Se2  2  0.0000  0.3697  0.1185  1.0
  Se  Se3  2  0.0000  0.8873  0.0937  1.0
]