data_Ta3Tc
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.86
_cell_length_b   2.86
_cell_length_c   9.01
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   110.8
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ta3Tc
_chemical_formula_sum   'Ta3 Tc1'
_cell_volume   68.92
_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  0.62  0.0  0.14  1.0
  Ta  Ta1  1  0.62  0.0  0.86  1.0
  Ta  Ta2  1  0.0  0.0  0.5  1.0
  Tc  Tc3  1  0.0  0.0  0.0  1.0

data_Ta3Tc
_symmetry_space_group_name_H-M   Pm
_cell_length_a   2.86
_cell_length_b   9.01
_cell_length_c   2.86
_cell_angle_alpha   90.0
_cell_angle_beta   110.8
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   6
_chemical_formula_structural   Ta3Tc
_chemical_formula_sum   'Ta3 Tc1'
_cell_volume   68.92
_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  2  0.62  0.14  0.0  1.0
  Ta  Ta1  1  0.0  0.5  0.0  1.0
  Tc  Tc2  1  0.0  0.0  0.0  1.0

Ta Ta Ta Tc
Ta3Tc crystallizes in the triclinic P1 space group. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a distorted L-shaped geometry to two equivalent Ta(3) and two equivalent Tc(1) atoms. There is one shorter (3.43 Å) and one longer (3.71 Å) Ta(1)-Ta(3) bond length. There is one shorter (1.67 Å) and one longer (2.20 Å) Ta(1)-Tc(1) bond length. In the second Ta site, Ta(2) is bonded in a distorted water-like geometry to two equivalent Ta(3) and two equivalent Tc(1) atoms. There is one shorter (3.43 Å) and one longer (3.71 Å) Ta(2)-Ta(3) bond length. There is one shorter (1.63 Å) and one longer (2.16 Å) Ta(2)-Tc(1) bond length. In the third Ta site, Ta(3) is bonded in a 10-coordinate geometry to two equivalent Ta(1), two equivalent Ta(2), and six equivalent Ta(3) atoms. There are four shorter (2.86 Å) and two longer (3.25 Å) Ta(3)-Ta(3) bond lengths. Tc(1) is bonded in a 4-coordinate geometry to two equivalent Ta(1) and two equivalent Ta(2) atoms.