data_TaTc3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.99
_cell_length_b   4.71
_cell_length_c   4.62
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TaTc3
_chemical_formula_sum   'Ta1 Tc3'
_cell_volume   64.99
_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  0.49  0.35  0.41  1.0
  Tc  Tc1  1  0.49  0.0  0.71  1.0
  Tc  Tc2  1  0.0  0.35  0.19  1.0
  Tc  Tc3  1  0.0  0.0  1.0  1.0

data_TaTc3
_symmetry_space_group_name_H-M   Pm
_cell_length_a   4.62
_cell_length_b   2.99
_cell_length_c   4.71
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   6
_chemical_formula_structural   TaTc3
_chemical_formula_sum   'Ta1 Tc3'
_cell_volume   64.99
_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
  Ta  Ta0  1  0.59  0.0  0.65  1.0
  Tc  Tc1  1  0.0  0.5  0.0  1.0
  Tc  Tc2  1  0.29  0.0  0.0  1.0
  Tc  Tc3  1  0.81  0.5  0.65  1.0

Ta Tc Tc Tc
TaTc3 crystallizes in the triclinic P1 space group. Ta(1) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Tc(1) and two equivalent Tc(2) atoms. There is one shorter (2.18 Å) and one longer (3.34 Å) Ta(1)-Tc(1) bond length. There is one shorter (1.80 Å) and one longer (1.83 Å) Ta(1)-Tc(2) bond length. There are three inequivalent Tc sites. In the first Tc site, Tc(1) is bonded in a 4-coordinate geometry to two equivalent Ta(1) and two equivalent Tc(3) atoms. There is one shorter (1.98 Å) and one longer (2.01 Å) Tc(1)-Tc(3) bond length. In the second Tc site, Tc(2) is bonded in a 2-coordinate geometry to two equivalent Ta(1) and one Tc(3) atom. The Tc(2)-Tc(3) bond length is 1.89 Å. In the third Tc site, Tc(3) is bonded in a distorted trigonal non-coplanar geometry to one Tc(2) and two equivalent Tc(1) atoms.