data_[Mg6Si4]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Mg  1.3100  1.5000  0.8600
  Si  1.9000  1.1000  0.5400
]
_symmetry_space_group_name_H-M [P-1]
_cell_length_a [4.4596]
_cell_length_b [5.4047]
_cell_length_c [9.0233]
_cell_angle_alpha [100.1288]
_cell_angle_beta [91.3544]
_cell_angle_gamma [104.8824]
_symmetry_Int_Tables_number [2]
_chemical_formula_structural [Mg3Si2]
_chemical_formula_sum '[Mg6 Si4]'
_cell_volume [206.3714]
_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  0.0978  0.4913  0.2429  1
  Mg  Mg1  2  0.2804  0.1038  0.6141  1
  Mg  Mg2  2  0.3373  0.1976  0.9553  1
  Si  Si3  2  0.2425  0.0135  0.2245  1
  Si  Si4  2  0.3948  0.6291  0.5976  1
]