data_TiAlSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.37
_cell_length_b   3.37
_cell_length_c   5.32
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TiAlSi2
_chemical_formula_sum   'Ti1 Al1 Si2'
_cell_volume   60.36
_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  0.0  0.66  1.0
  Al  Al0  1  0.0  0.0  0.0  1.0
  Si  Si1  1  0.68  0.68  0.37  1.0
  Si  Si2  1  0.68  0.68  0.95  1.0

data_TiAlSi2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.76
_cell_length_b   4.76
_cell_length_c   5.32
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   TiAlSi2
_chemical_formula_sum   'Ti2 Al2 Si4'
_cell_volume   120.73
_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  2  0.0  0.0  0.66  1.0
  Al  Al1  2  0.0  0.0  0.0  1.0
  Si  Si2  2  0.18  0.5  0.37  1.0
  Si  Si3  2  0.18  0.5  0.95  1.0

Ti Al Si Si
TiSi2Al crystallizes in the monoclinic Cm space group. Ti(1) is bonded in a 3-coordinate geometry to one Al(1), one Si(2), and three equivalent Si(1) atoms. The Ti(1)-Al(1) bond length is 1.81 Å. The Ti(1)-Si(2) bond length is 2.17 Å. There is one shorter (2.17 Å) and two longer (2.98 Å) Ti(1)-Si(1) bond lengths. Al(1) is bonded in a 5-coordinate geometry to one Ti(1), one Si(1), and three equivalent Si(2) atoms. The Al(1)-Si(1) bond length is 2.47 Å. There is one shorter (1.52 Å) and two longer (2.55 Å) Al(1)-Si(2) bond lengths. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a distorted single-bond geometry to three equivalent Ti(1), one Al(1), and one Si(2) atom. The Si(1)-Si(2) bond length is 2.19 Å. In the second Si site, Si(2) is bonded in a distorted single-bond geometry to one Ti(1), three equivalent Al(1), and one Si(1) atom.