data_[Mg4Si4O4]
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 [Cm]
_cell_length_a [9.7554]
_cell_length_b [2.9569]
_cell_length_c [7.0143]
_cell_angle_alpha [90.0000]
_cell_angle_beta [125.3300]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [8]
_chemical_formula_structural [MgSiO]
_chemical_formula_sum '[Mg4 Si4 O4]'
_cell_volume [165.0711]
_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  2  0.2993  0.5000  0.8075  1
  Mg  Mg1  2  0.4847  0.5000  0.3095  1
  Si  Si2  2  0.1187  0.5000  0.0109  1
  Si  Si3  2  0.4271  0.0000  0.5909  1
  O  O4  2  0.2374  0.0000  0.5685  1
  O  O5  2  0.4628  0.0000  0.0758  1
]