data_[Si2Ge2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Si  1.9000  1.1000  0.5400
  Ge  2.0100  1.2500  0.7700
]
_symmetry_space_group_name_H-M [P4/nmm]
_cell_length_a [3.6614]
_cell_length_b [3.6614]
_cell_length_c [17.6167]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [129]
_chemical_formula_structural [SiGe]
_chemical_formula_sum '[Si2 Ge2]'
_cell_volume [236.1725]
_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
[
  Si  Si0  2  0.0000  0.5000  0.5683  1
  Ge  Ge1  2  0.0000  0.5000  0.4257  1
]