data_TiAl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.04
_cell_length_b   7.04
_cell_length_c   2.8
_cell_angle_alpha   97.61
_cell_angle_beta   97.61
_cell_angle_gamma   80.92
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TiAl
_chemical_formula_sum   'Ti4 Al4'
_cell_volume   134.79
_cell_formula_units_Z   4
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  Ti4  1  0.11  0.28  0.38  1.0
  Ti  Ti5  1  0.22  0.0  0.69  1.0
  Ti  Ti6  1  0.01  0.0  0.07  1.0
  Ti  Ti7  1  0.11  0.72  0.38  1.0
  Al  Al0  1  0.57  0.0  0.69  1.0
  Al  Al1  1  0.68  0.72  0.0  1.0
  Al  Al2  1  0.65  0.0  0.07  1.0
  Al  Al3  1  0.68  0.28  0.0  1.0

data_TiAl
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.8
_cell_length_b   7.04
_cell_length_c   7.04
_cell_angle_alpha   80.92
_cell_angle_beta   82.39
_cell_angle_gamma   82.39
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TiAl
_chemical_formula_sum   'Ti4 Al4'
_cell_volume   134.79
_cell_formula_units_Z   4
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  Ti0  1  0.07  0.99  0.0  1.0
  Ti  Ti1  1  0.38  0.89  0.28  1.0
  Ti  Ti2  1  0.38  0.89  0.72  1.0
  Ti  Ti3  1  0.69  0.78  0.0  1.0
  Al  Al4  1  -0.0  0.32  0.72  1.0
  Al  Al5  1  -0.0  0.32  0.28  1.0
  Al  Al6  1  0.07  0.35  0.0  1.0
  Al  Al7  1  0.69  0.43  0.0  1.0

Ti Ti Ti Ti Al Al Al Al
Ti Ti Ti Ti Al Al Al Al 0 2 o o o 0 1 o o - 0 1 o o o 0 0 o o + 1 3 o - o 1 2 o o o 1 2 o o + 2 3 o - o 2 3 o - - 3 3 o o + 4 6 o o + 4 5 o - + 4 7 o o + 5 6 o + o 6 7 o o o 
TiAl crystallizes in the triclinic P1 space group. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 7-coordinate geometry to one Ti(3), one Ti(4), two equivalent Ti(1), two equivalent Ti(2), and one Al(4) atom. The Ti(1)-Ti(3) bond length is 2.26 Å. The Ti(1)-Ti(4) bond length is 3.04 Å. Both Ti(1)-Ti(1) bond lengths are 2.80 Å. There is one shorter (2.26 Å) and one longer (2.67 Å) Ti(1)-Ti(2) bond length. The Ti(1)-Al(4) bond length is 3.10 Å. In the second Ti site, Ti(2) is bonded in a 5-coordinate geometry to one Ti(4), two equivalent Ti(1), two equivalent Ti(3), and one Al(1) atom. The Ti(2)-Ti(4) bond length is 2.26 Å. There is one shorter (1.92 Å) and one longer (2.13 Å) Ti(2)-Ti(3) bond length. The Ti(2)-Al(1) bond length is 2.51 Å. In the third Ti site, Ti(3) is bonded in a 5-coordinate geometry to one Ti(1), two equivalent Ti(2), two equivalent Ti(4), one Al(3), and one Al(4) atom. There is one shorter (2.26 Å) and one longer (2.67 Å) Ti(3)-Ti(4) bond length. The Ti(3)-Al(3) bond length is 2.51 Å. The Ti(3)-Al(4) bond length is 2.82 Å. In the fourth Ti site, Ti(4) is bonded in a 7-coordinate geometry to one Ti(1), one Ti(2), two equivalent Ti(3), two equivalent Ti(4), and one Al(2) atom. Both Ti(4)-Ti(4) bond lengths are 2.80 Å. The Ti(4)-Al(2) bond length is 3.10 Å. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded in a 1-coordinate geometry to one Ti(2), one Al(4), and two equivalent Al(3) atoms. The Al(1)-Al(4) bond length is 2.26 Å. There is one shorter (1.12 Å) and one longer (1.90 Å) Al(1)-Al(3) bond length. In the second Al site, Al(2) is bonded in a 1-coordinate geometry to one Ti(4), one Al(3), and one Al(4) atom. The Al(2)-Al(3) bond length is 1.96 Å. The Al(2)-Al(4) bond length is 3.04 Å. In the third Al site, Al(3) is bonded in a 5-coordinate geometry to one Ti(3), one Al(2), one Al(4), and two equivalent Al(1) atoms. The Al(3)-Al(4) bond length is 2.07 Å. In the fourth Al site, Al(4) is bonded to one Ti(1), one Ti(3), one Al(1), one Al(2), one Al(3), and two equivalent Al(4) atoms to form distorted corner-sharing AlTi2Al5 pentagonal bipyramids. Both Al(4)-Al(4) bond lengths are 2.80 Å.