data_Ta2AlCo
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.84
_cell_length_b   2.84
_cell_length_c   7.7
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ta2AlCo
_chemical_formula_sum   'Ta2 Al1 Co1'
_cell_volume   62.13
_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
  Ta  Ta2  1  0.42  0.42  0.58  1.0
  Ta  Ta3  1  0.42  0.42  0.12  1.0
  Al  Al0  1  0.0  0.0  0.0  1.0
  Co  Co1  1  0.0  0.0  0.85  1.0

data_Ta2AlCo
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.02
_cell_length_b   4.02
_cell_length_c   7.7
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Ta2AlCo
_chemical_formula_sum   'Ta4 Al2 Co2'
_cell_volume   124.27
_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
  Ta  Ta0  2  0.42  0.0  0.12  1.0
  Ta  Ta1  2  0.42  0.0  0.58  1.0
  Al  Al2  2  0.0  0.0  0.0  1.0
  Co  Co3  2  0.0  0.0  0.85  1.0

Ta Ta Al Co
Ta2CoAl crystallizes in the monoclinic Cm space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 9-coordinate geometry to one Ta(2), four equivalent Ta(1), and four equivalent Co(1) atoms. The Ta(1)-Ta(2) bond length is 3.52 Å. All Ta(1)-Ta(1) bond lengths are 2.84 Å. There are a spread of Ta(1)-Co(1) bond distances ranging from 2.69-3.13 Å. In the second Ta site, Ta(2) is bonded in a 4-coordinate geometry to one Ta(1) and four equivalent Al(1) atoms. There are a spread of Ta(2)-Al(1) bond distances ranging from 1.93-2.51 Å. Co(1) is bonded in a single-bond geometry to four equivalent Ta(1) and one Al(1) atom. The Co(1)-Al(1) bond length is 1.16 Å. Al(1) is bonded in a distorted single-bond geometry to four equivalent Ta(2) and one Co(1) atom.