data_Mg2FeSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.92
_cell_length_b   5.4
_cell_length_c   5.4
_cell_angle_alpha   34.63
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2FeSi
_chemical_formula_sum   'Mg2 Fe1 Si1'
_cell_volume   64.94
_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  Mg1  1  0.0  0.0  0.4  1.0
  Mg  Mg2  1  0.96  0.0  0.32  1.0
  Fe  Fe0  1  0.96  0.0  0.42  1.0
  Si  Si3  1  0.0  0.0  0.34  1.0

data_Mg2FeSi
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.21
_cell_length_b   3.92
_cell_length_c   5.4
_cell_angle_alpha   90.0
_cell_angle_beta   107.32
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2FeSi
_chemical_formula_sum   'Mg2 Fe1 Si1'
_cell_volume   64.94
_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  0.6  0.0  0.6  1.0
  Mg  Mg1  1  0.68  0.96  0.68  1.0
  Fe  Fe2  1  0.58  0.96  0.58  1.0
  Si  Si3  1  0.66  0.0  0.66  1.0

Mg Mg Fe Si
Mg Mg Fe Si 0 2 - o o 1 3 + o o 