data_TaNi3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.54
_cell_length_b   4.54
_cell_length_c   4.54
_cell_angle_alpha   132.78
_cell_angle_beta   132.78
_cell_angle_gamma   69.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TaNi3
_chemical_formula_sum   'Ta1 Ni3'
_cell_volume   49.5
_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  0.0  0.0  0.74  1.0
  Ni  Ni0  1  0.0  0.0  0.0  1.0
  Ni  Ni1  1  0.82  0.0  0.87  1.0
  Ni  Ni2  1  0.0  0.82  0.87  1.0

data_TaNi3
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.14
_cell_length_b   5.14
_cell_length_c   4.54
_cell_angle_alpha   90.0
_cell_angle_beta   124.5
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   TaNi3
_chemical_formula_sum   'Ta2 Ni6'
_cell_volume   99.0
_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  0.0  0.0  0.74  1.0
  Ni  Ni1  4  0.09  0.09  0.05  1.0
  Ni  Ni2  2  0.0  0.0  0.0  1.0

Ta Ni Ni Ni
Ni3Ta crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Ni3Ta clusters. Ta(1) is bonded in a 3-coordinate geometry to one Ni(1) and two equivalent Ni(2) atoms. The Ta(1)-Ni(1) bond length is 1.17 Å. Both Ta(1)-Ni(2) bond lengths are 1.30 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 3-coordinate geometry to one Ta(1) and two equivalent Ni(2) atoms. Both Ni(1)-Ni(2) bond lengths are 0.61 Å. In the second Ni site, Ni(2) is bonded in a distorted single-bond geometry to one Ta(1) and one Ni(1) atom.