data_Ti2Al2Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.32
_cell_length_b   7.32
_cell_length_c   7.32
_cell_angle_alpha   151.5
_cell_angle_beta   151.5
_cell_angle_gamma   40.74
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ti2Al2Si
_chemical_formula_sum   'Ti2 Al2 Si1'
_cell_volume   89.08
_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
  Ti  Ti3  1  0.0  0.8  0.43  1.0
  Ti  Ti4  1  0.8  0.0  0.43  1.0
  Al  Al0  1  0.0  0.0  0.12  1.0
  Al  Al1  1  0.0  0.0  0.6  1.0
  Si  Si2  1  0.0  0.0  0.0  1.0

data_Ti2Al2Si
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.1
_cell_length_b   5.1
_cell_length_c   7.32
_cell_angle_alpha   90.0
_cell_angle_beta   110.37
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Ti2Al2Si
_chemical_formula_sum   'Ti4 Al4 Si2'
_cell_volume   178.16
_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
  Ti  Ti0  4  0.4  0.4  0.37  1.0
  Al  Al1  2  0.0  0.0  0.4  1.0
  Al  Al2  2  0.0  0.0  0.88  1.0
  Si  Si3  2  0.0  0.0  0.0  1.0

Ti Ti Al Al Si
Ti Ti Al Al Si 0 3 o + o 1 3 + o o 2 4 o o o 