data_Mg2Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.29
_cell_length_b   5.29
_cell_length_c   5.29
_cell_angle_alpha   146.23
_cell_angle_beta   135.1
_cell_angle_gamma   57.34
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2Si
_chemical_formula_sum   'Mg2 Si1'
_cell_volume   57.61
_cell_formula_units_Z   1
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  0.09  1.0
  Mg  Mg1  1  0.0  0.0  0.19  1.0
  Si  Si2  1  0.0  0.0  0.0  1.0

data_Mg2Si
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.07
_cell_length_b   4.04
_cell_length_c   5.29
_cell_angle_alpha   112.45
_cell_angle_beta   106.89
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2Si
_chemical_formula_sum   'Mg2 Si1'
_cell_volume   57.61
_cell_formula_units_Z   1
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  0.09  0.09  1.0
  Mg  Mg1  1  0.0  0.19  0.19  1.0
  Si  Si2  1  0.0  0.0  0.0  1.0

Mg Mg Si
Mg Mg Si 0 2 o o o 0 1 o o o 