data_Ta2CoBi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.31
_cell_length_b   5.31
_cell_length_c   5.31
_cell_angle_alpha   136.3
_cell_angle_beta   136.3
_cell_angle_gamma   63.51
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ta2CoBi
_chemical_formula_sum   'Ta2 Co1 Bi1'
_cell_volume   70.42
_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  0.98  0.0  0.26  1.0
  Ta  Ta3  1  0.0  0.98  0.26  1.0
  Co  Co1  1  0.0  0.0  0.0  1.0
  Bi  Bi0  1  0.0  0.0  0.51  1.0

data_Ta2CoBi
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.59
_cell_length_b   5.59
_cell_length_c   5.31
_cell_angle_alpha   90.0
_cell_angle_beta   121.76
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Ta2CoBi
_chemical_formula_sum   'Ta4 Co2 Bi2'
_cell_volume   140.85
_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  4  0.01  0.01  0.28  1.0
  Co  Co1  2  0.0  0.0  0.0  1.0
  Bi  Bi2  2  0.0  0.0  0.51  1.0

Ta Ta Co Bi
Ta2CoBi crystallizes in the monoclinic Cm space group. Ta(1) is bonded in a distorted single-bond geometry to one Ta(1), one Co(1), and two equivalent Bi(1) atoms. The Ta(1)-Ta(1) bond length is 0.14 Å. The Ta(1)-Co(1) bond length is 1.46 Å. There is one shorter (1.27 Å) and one longer (3.58 Å) Ta(1)-Bi(1) bond length. Co(1) is bonded in a 3-coordinate geometry to two equivalent Ta(1) and one Bi(1) atom. The Co(1)-Bi(1) bond length is 2.59 Å. Bi(1) is bonded in a 5-coordinate geometry to four equivalent Ta(1) and one Co(1) atom.