data_[Mg8Si4O16]
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
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [I-42d]
_cell_length_a [7.0422]
_cell_length_b [7.0422]
_cell_length_c [6.6314]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [122]
_chemical_formula_structural [Mg2SiO4]
_chemical_formula_sum '[Mg8 Si4 O16]'
_cell_volume [328.8653]
_cell_formula_units_Z [4]
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  8  0.1583  0.7500  0.1250  1.0
  Si  Si1  4  0.0000  0.0000  0.5000  1.0
  O  O2  16  0.0084  0.3063  0.8906  1.0
]