data_TaCo2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.19
_cell_length_b   4.19
_cell_length_c   3.25
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   102.35
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TaCo2Se
_chemical_formula_sum   'Ta1 Co2 Se1'
_cell_volume   55.67
_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  Ta3  1  0.63  0.0  0.0  1.0
  Co  Co0  1  0.31  0.37  0.63  1.0
  Co  Co1  1  0.31  0.63  0.63  1.0
  Se  Se2  1  0.0  0.0  0.0  1.0

data_TaCo2Se
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.25
_cell_length_b   4.19
_cell_length_c   4.19
_cell_angle_alpha   102.35
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TaCo2Se
_chemical_formula_sum   'Ta1 Co2 Se1'
_cell_volume   55.67
_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  Ta0  1  0.0  0.63  0.0  1.0
  Co  Co1  1  0.63  0.31  0.37  1.0
  Co  Co2  1  0.63  0.31  0.63  1.0
  Se  Se3  1  0.0  0.0  0.0  1.0

Ta Co Co Se
TaCo2Se crystallizes in the triclinic P1 space group. Ta(1) is bonded in a distorted single-bond geometry to two equivalent Co(2) and one Se(1) atom. There is one shorter (2.17 Å) and one longer (2.71 Å) Ta(1)-Co(2) bond length. The Ta(1)-Se(1) bond length is 1.57 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 2-coordinate geometry to one Co(2) and one Se(1) atom. The Co(1)-Co(2) bond length is 1.10 Å. The Co(1)-Se(1) bond length is 2.17 Å. In the second Co site, Co(2) is bonded in a 5-coordinate geometry to two equivalent Ta(1), one Co(1), and two equivalent Se(1) atoms. There is one shorter (2.54 Å) and one longer (3.02 Å) Co(2)-Se(1) bond length. Se(1) is bonded in a 1-coordinate geometry to one Ta(1), one Co(1), and two equivalent Co(2) atoms.