data_Si2GeSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.89
_cell_length_b   5.89
_cell_length_c   5.89
_cell_angle_alpha   142.48
_cell_angle_beta   142.48
_cell_angle_gamma   54.11
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2GeSe
_chemical_formula_sum   'Si2 Ge1 Se1'
_cell_volume   75.26
_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
  Si  Si2  1  0.0  0.89  0.62  1.0
  Si  Si3  1  0.89  0.0  0.62  1.0
  Ge  Ge0  1  0.0  0.0  0.0  1.0
  Se  Se1  1  0.0  0.0  0.24  1.0

data_Si2GeSe
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.36
_cell_length_b   5.36
_cell_length_c   5.89
_cell_angle_alpha   90.0
_cell_angle_beta   117.06
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Si2GeSe
_chemical_formula_sum   'Si4 Ge2 Se2'
_cell_volume   150.53
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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
  Si  Si0  4  0.45  0.45  0.27  1.0
  Ge  Ge1  2  0.0  0.0  0.0  1.0
  Se  Se2  2  0.0  0.0  0.76  1.0

Si Si Ge Se