data_Mg2Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.16
_cell_length_b   8.12
_cell_length_c   8.17
_cell_angle_alpha   64.49
_cell_angle_beta   75.51
_cell_angle_gamma   76.6
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2Si
_chemical_formula_sum   'Mg8 Si4'
_cell_volume   238.61
_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  1  0.03  0.34  0.46  1.0
  Mg  Mg1  1  0.06  0.69  0.81  1.0
  Mg  Mg2  1  0.1  0.27  0.8  1.0
  Mg  Mg3  1  0.96  0.49  0.61  1.0
  Mg  Mg4  1  0.04  0.51  0.63  1.0
  Mg  Mg5  1  0.13  0.54  0.65  1.0
  Mg  Mg6  1  0.0  0.0  0.0  1.0
  Mg  Mg7  1  0.98  0.76  0.47  1.0
  Si  Si8  1  0.1  0.56  0.12  1.0
  Si  Si9  1  0.98  0.47  0.15  1.0
  Si  Si10  1  0.02  0.64  0.66  1.0
  Si  Si11  1  0.07  0.38  0.6  1.0

data_Mg2Si
_symmetry_space_group_name_H-M   P1
_cell_length_a   4.16
_cell_length_b   8.12
_cell_length_c   8.17
_cell_angle_alpha   64.49
_cell_angle_beta   75.51
_cell_angle_gamma   76.6
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2Si
_chemical_formula_sum   'Mg8 Si4'
_cell_volume   238.61
_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  1  0.0  0.0  0.0  1.0
  Mg  Mg1  1  0.03  0.34  0.46  1.0
  Mg  Mg2  1  0.04  0.51  0.63  1.0
  Mg  Mg3  1  0.06  0.69  0.81  1.0
  Mg  Mg4  1  0.1  0.27  0.8  1.0
  Mg  Mg5  1  0.13  0.54  0.65  1.0
  Mg  Mg6  1  0.96  0.49  0.61  1.0
  Mg  Mg7  1  0.98  0.76  0.47  1.0
  Si  Si8  1  0.02  0.64  0.66  1.0
  Si  Si9  1  0.07  0.38  0.6  1.0
  Si  Si10  1  0.1  0.56  0.12  1.0
  Si  Si11  1  0.98  0.47  0.15  1.0

Mg Mg Mg Mg Mg Mg Mg Mg Si Si Si Si