data_[Mg4Fe4Si4O20]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Mg  1.3100  1.5000  0.8600
  Fe  1.8300  1.4000  0.8525
  Si  1.9000  1.1000  0.5400
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [Cc]
_cell_length_a [6.8200]
_cell_length_b [8.3913]
_cell_length_c [7.0070]
_cell_angle_alpha [90.0000]
_cell_angle_beta [115.6909]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [9]
_chemical_formula_structural [MgFeSiO5]
_chemical_formula_sum '[Mg4 Fe4 Si4 O20]'
_cell_volume [361.3618]
_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  4  0.0599  0.1796  0.3161  1
  Fe  Fe1  4  0.4961  0.0104  0.0122  1
  Si  Si2  4  0.4795  0.3410  0.2568  1
  O  O3  4  0.0393  0.2534  0.5852  1
  O  O4  4  0.1812  0.0453  0.9162  1
  O  O5  4  0.3124  0.4920  0.1434  1
  O  O6  4  0.3930  0.2185  0.3862  1
  O  O7  4  0.4933  0.0842  0.7571  1
]