data_TiAlCu2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.82
_cell_length_b   2.82
_cell_length_c   7.04
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   92.14
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TiAlCu2
_chemical_formula_sum   'Ti1 Al1 Cu2'
_cell_volume   55.83
_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  0.52  1.0
  Al  Al0  1  0.0  0.0  0.0  1.0
  Cu  Cu1  1  0.95  0.0  0.66  1.0
  Cu  Cu2  1  0.95  0.0  0.38  1.0

data_TiAlCu2
_symmetry_space_group_name_H-M   Pm
_cell_length_a   2.82
_cell_length_b   2.82
_cell_length_c   7.04
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   6
_chemical_formula_structural   TiAlCu2
_chemical_formula_sum   'Ti1 Al1 Cu2'
_cell_volume   55.87
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '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  0.0  0.0  0.52  1.0
  Al  Al1  1  0.0  0.0  0.0  1.0
  Cu  Cu2  1  0.95  0.0  0.38  1.0
  Cu  Cu3  1  0.95  0.0  0.66  1.0

Ti Al Cu Cu
AlCu2Ti crystallizes in the monoclinic Pm space group. Ti(1) is bonded in a linear geometry to one Cu(1) and one Cu(2) atom. The Ti(1)-Cu(1) bond length is 0.97 Å. The Ti(1)-Cu(2) bond length is 0.97 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a single-bond geometry to one Ti(1) and one Al(1) atom. The Cu(1)-Al(1) bond length is 2.43 Å. In the second Cu site, Cu(2) is bonded in a single-bond geometry to one Ti(1) and one Al(1) atom. The Cu(2)-Al(1) bond length is 2.68 Å. Al(1) is bonded to one Cu(1), one Cu(2), and four equivalent Al(1) atoms to form a mixture of distorted edge and corner-sharing AlAl4Cu2 octahedra. The corner-sharing octahedra are not tilted. All Al(1)-Al(1) bond lengths are 2.82 Å.