The material structure described by Ni3Ta is beta Cu3Ti-like structured and crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one Ni(3), two equivalent Ni(1), three equivalent Ni(4), and six equivalent Ni(2) atoms to form TaNi12 cuboctahedra that share  a cornercorner with one Ta(2)Ni12 cuboctahedra, corners with two equivalent Ta(1)Ni12 cuboctahedra, corners with four equivalent Ni(1)Ta4Ni8 cuboctahedra, corners with four equivalent Ni(3)Ta4Ni8 cuboctahedra, corners with four equivalent Ni(4)Ta4Ni8 cuboctahedra, edges with three equivalent Ta(2)Ni12 cuboctahedra, edges with four equivalent Ta(1)Ni12 cuboctahedra, edges with six equivalent Ni(1)Ta4Ni8 cuboctahedra, edges with eight equivalent Ni(2)Ta4Ni8 cuboctahedra, faces with two equivalent Ta(1)Ni12 cuboctahedra, faces with two equivalent Ni(1)Ta4Ni8 cuboctahedra, faces with two equivalent Ni(3)Ta4Ni8 cuboctahedra, faces with three equivalent Ta(2)Ni12 cuboctahedra, faces with four equivalent Ni(4)Ta4Ni8 cuboctahedra, and faces with six equivalent Ni(2)Ta4Ni8 cuboctahedra. In the second Ta site, Ta(2) is bonded to one Ni(4), two equivalent Ni(2), three equivalent Ni(3), and six equivalent Ni(1) atoms to form TaNi12 cuboctahedra that share  a cornercorner with one Ta(1)Ni12 cuboctahedra, corners with two equivalent Ta(2)Ni12 cuboctahedra, corners with four equivalent Ni(2)Ta4Ni8 cuboctahedra, corners with four equivalent Ni(3)Ta4Ni8 cuboctahedra, corners with four equivalent Ni(4)Ta4Ni8 cuboctahedra, edges with three equivalent Ta(1)Ni12 cuboctahedra, edges with four equivalent Ta(2)Ni12 cuboctahedra, edges with six equivalent Ni(2)Ta4Ni8 cuboctahedra, edges with eight equivalent Ni(1)Ta4Ni8 cuboctahedra, faces with two equivalent Ta(2)Ni12 cuboctahedra, faces with two equivalent Ni(2)Ta4Ni8 cuboctahedra, faces with two equivalent Ni(4)Ta4Ni8 cuboctahedra, faces with three equivalent Ta(1)Ni12 cuboctahedra, faces with four equivalent Ni(3)Ta4Ni8 cuboctahedra, and faces with six equivalent Ni(1)Ta4Ni8 cuboctahedra. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one Ta(1), three equivalent Ta(2), one Ni(2), one Ni(4), three equivalent Ni(1), and three equivalent Ni(3) atoms to form distorted NiTa4Ni8 cuboctahedra that share corners with two equivalent Ta(1)Ni12 cuboctahedra, corners with two equivalent Ni(4)Ta4Ni8 cuboctahedra, corners with five equivalent Ni(2)Ta4Ni8 cuboctahedra, corners with six equivalent Ni(1)Ta4Ni8 cuboctahedra, edges with three equivalent Ta(1)Ni12 cuboctahedra, edges with three equivalent Ni(2)Ta4Ni8 cuboctahedra, edges with three equivalent Ni(4)Ta4Ni8 cuboctahedra, edges with four equivalent Ta(2)Ni12 cuboctahedra, edges with four equivalent Ni(1)Ta4Ni8 cuboctahedra, edges with four equivalent Ni(3)Ta4Ni8 cuboctahedra,  a faceface with one Ta(1)Ni12 cuboctahedra,  a faceface with one Ni(4)Ta4Ni8 cuboctahedra, faces with three equivalent Ta(2)Ni12 cuboctahedra, faces with three equivalent Ni(3)Ta4Ni8 cuboctahedra, faces with five equivalent Ni(2)Ta4Ni8 cuboctahedra, and faces with six equivalent Ni(1)Ta4Ni8 cuboctahedra. In the second Ni site, Ni(2) is bonded to one Ta(2), three equivalent Ta(1), one Ni(1), one Ni(3), three equivalent Ni(2), and three equivalent Ni(4) atoms to form distorted NiTa4Ni8 cuboctahedra that share corners with two equivalent Ta(2)Ni12 cuboctahedra, corners with two equivalent Ni(3)Ta4Ni8 cuboctahedra, corners with five equivalent Ni(1)Ta4Ni8 cuboctahedra, corners with six equivalent Ni(2)Ta4Ni8 cuboctahedra, edges with three equivalent Ta(2)Ni12 cuboctahedra, edges with three equivalent Ni(1)Ta4Ni8 cuboctahedra, edges with three equivalent Ni(3)Ta4Ni8 cuboctahedra, edges with four equivalent Ta(1)Ni12 cuboctahedra, edges with four equivalent Ni(2)Ta4Ni8 cuboctahedra, edges with four equivalent Ni(4)Ta4Ni8 cuboctahedra,  a faceface with one Ta(2)Ni12 cuboctahedra,  a faceface with one Ni(3)Ta4Ni8 cuboctahedra, faces with three equivalent Ta(1)Ni12 cuboctahedra, faces with three equivalent Ni(4)Ta4Ni8 cuboctahedra, faces with five equivalent Ni(1)Ta4Ni8 cuboctahedra, and faces with six equivalent Ni(2)Ta4Ni8 cuboctahedra. In the third Ni site, Ni(3) is bonded to one Ta(1), three equivalent Ta(2), two equivalent Ni(2), and six equivalent Ni(1) atoms to form distorted NiTa4Ni8 cuboctahedra that share  a cornercorner with one Ni(4)Ta4Ni8 cuboctahedra, corners with two equivalent Ni(3)Ta4Ni8 cuboctahedra, corners with four equivalent Ta(1)Ni12 cuboctahedra, corners with four equivalent Ta(2)Ni12 cuboctahedra, corners with four equivalent Ni(2)Ta4Ni8 cuboctahedra, edges with three equivalent Ni(4)Ta4Ni8 cuboctahedra, edges with four equivalent Ni(3)Ta4Ni8 cuboctahedra, edges with six equivalent Ni(2)Ta4Ni8 cuboctahedra, edges with eight equivalent Ni(1)Ta4Ni8 cuboctahedra, faces with two equivalent Ta(1)Ni12 cuboctahedra, faces with two equivalent Ni(2)Ta4Ni8 cuboctahedra, faces with two equivalent Ni(3)Ta4Ni8 cuboctahedra, faces with three equivalent Ni(4)Ta4Ni8 cuboctahedra, faces with four equivalent Ta(2)Ni12 cuboctahedra, and faces with six equivalent Ni(1)Ta4Ni8 cuboctahedra. In the fourth Ni site, Ni(4) is bonded to one Ta(2), three equivalent Ta(1), two equivalent Ni(1), and six equivalent Ni(2) atoms to form distorted NiTa4Ni8 cuboctahedra that share  a cornercorner with one Ni(3)Ta4Ni8 cuboctahedra, corners with two equivalent Ni(4)Ta4Ni8 cuboctahedra, corners with four equivalent Ta(1)Ni12 cuboctahedra, corners with four equivalent Ta(2)Ni12 cuboctahedra, corners with four equivalent Ni(1)Ta4Ni8 cuboctahedra, edges with three equivalent Ni(3)Ta4Ni8 cuboctahedra, edges with four equivalent Ni(4)Ta4Ni8 cuboctahedra, edges with six equivalent Ni(1)Ta4Ni8 cuboctahedra, edges with eight equivalent Ni(2)Ta4Ni8 cuboctahedra, faces with two equivalent Ta(2)Ni12 cuboctahedra, faces with two equivalent Ni(1)Ta4Ni8 cuboctahedra, faces with two equivalent Ni(4)Ta4Ni8 cuboctahedra, faces with three equivalent Ni(3)Ta4Ni8 cuboctahedra, faces with four equivalent Ta(1)Ni12 cuboctahedra, and faces with six equivalent Ni(2)Ta4Ni8 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_TaNi3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.500
_cell_length_b   5.078
_cell_length_c   8.564
_cell_angle_alpha   90.000
_cell_angle_beta   100.877
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   192.188
_cell_formula_units_Z   4
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  0.388  0.750  0.622  1.0
  Ta  Ta1  1  0.612  0.250  0.378  1.0
  Ta  Ta2  1  0.210  0.750  0.128  1.0
  Ta  Ta3  1  0.790  0.250  0.872  1.0
  Ni  Ni4  1  0.294  0.999  0.877  1.0
  Ni  Ni5  1  0.886  0.997  0.627  1.0
  Ni  Ni6  1  0.798  0.750  0.873  1.0
  Ni  Ni7  1  0.114  0.497  0.373  1.0
  Ni  Ni8  1  0.634  0.750  0.376  1.0
  Ni  Ni9  1  0.294  0.501  0.877  1.0
  Ni  Ni10  1  0.366  0.250  0.624  1.0
  Ni  Ni11  1  0.706  0.001  0.123  1.0
  Ni  Ni12  1  0.706  0.499  0.123  1.0
  Ni  Ni13  1  0.114  0.003  0.373  1.0
  Ni  Ni14  1  0.202  0.250  0.127  1.0
  Ni  Ni15  1  0.886  0.503  0.627  1.0
[/CIF]
.
The material structure described by Ni3Ta is beta Cu3Ti-like structured and crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one Ni(3), two equivalent Ni(1), three equivalent Ni(4), and six equivalent Ni(2) atoms to form TaNi12 cuboctahedra that share  a cornercorner with one Ta(2)Ni12 cuboctahedra, corners with two equivalent Ta(1)Ni12 cuboctahedra, corners with four equivalent Ni(1)Ta4Ni8 cuboctahedra, corners with four equivalent Ni(3)Ta4Ni8 cuboctahedra, corners with four equivalent Ni(4)Ta4Ni8 cuboctahedra, edges with three equivalent Ta(2)Ni12 cuboctahedra, edges with four equivalent Ta(1)Ni12 cuboctahedra, edges with six equivalent Ni(1)Ta4Ni8 cuboctahedra, edges with eight equivalent Ni(2)Ta4Ni8 cuboctahedra, faces with two equivalent Ta(1)Ni12 cuboctahedra, faces with two equivalent Ni(1)Ta4Ni8 cuboctahedra, faces with two equivalent Ni(3)Ta4Ni8 cuboctahedra, faces with three equivalent Ta(2)Ni12 cuboctahedra, faces with four equivalent Ni(4)Ta4Ni8 cuboctahedra, and faces with six equivalent Ni(2)Ta4Ni8 cuboctahedra. In the second Ta site, Ta(2) is bonded to one Ni(4), two equivalent Ni(2), three equivalent Ni(3), and six equivalent Ni(1) atoms to form TaNi12 cuboctahedra that share  a cornercorner with one Ta(1)Ni12 cuboctahedra, corners with two equivalent Ta(2)Ni12 cuboctahedra, corners with four equivalent Ni(2)Ta4Ni8 cuboctahedra, corners with four equivalent Ni(3)Ta4Ni8 cuboctahedra, corners with four equivalent Ni(4)Ta4Ni8 cuboctahedra, edges with three equivalent Ta(1)Ni12 cuboctahedra, edges with four equivalent Ta(2)Ni12 cuboctahedra, edges with six equivalent Ni(2)Ta4Ni8 cuboctahedra, edges with eight equivalent Ni(1)Ta4Ni8 cuboctahedra, faces with two equivalent Ta(2)Ni12 cuboctahedra, faces with two equivalent Ni(2)Ta4Ni8 cuboctahedra, faces with two equivalent Ni(4)Ta4Ni8 cuboctahedra, faces with three equivalent Ta(1)Ni12 cuboctahedra, faces with four equivalent Ni(3)Ta4Ni8 cuboctahedra, and faces with six equivalent Ni(1)Ta4Ni8 cuboctahedra. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one Ta(1), three equivalent Ta(2), one Ni(2), one Ni(4), three equivalent Ni(1), and three equivalent Ni(3) atoms to form distorted NiTa4Ni8 cuboctahedra that share corners with two equivalent Ta(1)Ni12 cuboctahedra, corners with two equivalent Ni(4)Ta4Ni8 cuboctahedra, corners with five equivalent Ni(2)Ta4Ni8 cuboctahedra, corners with six equivalent Ni(1)Ta4Ni8 cuboctahedra, edges with three equivalent Ta(1)Ni12 cuboctahedra, edges with three equivalent Ni(2)Ta4Ni8 cuboctahedra, edges with three equivalent Ni(4)Ta4Ni8 cuboctahedra, edges with four equivalent Ta(2)Ni12 cuboctahedra, edges with four equivalent Ni(1)Ta4Ni8 cuboctahedra, edges with four equivalent Ni(3)Ta4Ni8 cuboctahedra,  a faceface with one Ta(1)Ni12 cuboctahedra,  a faceface with one Ni(4)Ta4Ni8 cuboctahedra, faces with three equivalent Ta(2)Ni12 cuboctahedra, faces with three equivalent Ni(3)Ta4Ni8 cuboctahedra, faces with five equivalent Ni(2)Ta4Ni8 cuboctahedra, and faces with six equivalent Ni(1)Ta4Ni8 cuboctahedra. In the second Ni site, Ni(2) is bonded to one Ta(2), three equivalent Ta(1), one Ni(1), one Ni(3), three equivalent Ni(2), and three equivalent Ni(4) atoms to form distorted NiTa4Ni8 cuboctahedra that share corners with two equivalent Ta(2)Ni12 cuboctahedra, corners with two equivalent Ni(3)Ta4Ni8 cuboctahedra, corners with five equivalent Ni(1)Ta4Ni8 cuboctahedra, corners with six equivalent Ni(2)Ta4Ni8 cuboctahedra, edges with three equivalent Ta(2)Ni12 cuboctahedra, edges with three equivalent Ni(1)Ta4Ni8 cuboctahedra, edges with three equivalent Ni(3)Ta4Ni8 cuboctahedra, edges with four equivalent Ta(1)Ni12 cuboctahedra, edges with four equivalent Ni(2)Ta4Ni8 cuboctahedra, edges with four equivalent Ni(4)Ta4Ni8 cuboctahedra,  a faceface with one Ta(2)Ni12 cuboctahedra,  a faceface with one Ni(3)Ta4Ni8 cuboctahedra, faces with three equivalent Ta(1)Ni12 cuboctahedra, faces with three equivalent Ni(4)Ta4Ni8 cuboctahedra, faces with five equivalent Ni(1)Ta4Ni8 cuboctahedra, and faces with six equivalent Ni(2)Ta4Ni8 cuboctahedra. In the third Ni site, Ni(3) is bonded to one Ta(1), three equivalent Ta(2), two equivalent Ni(2), and six equivalent Ni(1) atoms to form distorted NiTa4Ni8 cuboctahedra that share  a cornercorner with one Ni(4)Ta4Ni8 cuboctahedra, corners with two equivalent Ni(3)Ta4Ni8 cuboctahedra, corners with four equivalent Ta(1)Ni12 cuboctahedra, corners with four equivalent Ta(2)Ni12 cuboctahedra, corners with four equivalent Ni(2)Ta4Ni8 cuboctahedra, edges with three equivalent Ni(4)Ta4Ni8 cuboctahedra, edges with four equivalent Ni(3)Ta4Ni8 cuboctahedra, edges with six equivalent Ni(2)Ta4Ni8 cuboctahedra, edges with eight equivalent Ni(1)Ta4Ni8 cuboctahedra, faces with two equivalent Ta(1)Ni12 cuboctahedra, faces with two equivalent Ni(2)Ta4Ni8 cuboctahedra, faces with two equivalent Ni(3)Ta4Ni8 cuboctahedra, faces with three equivalent Ni(4)Ta4Ni8 cuboctahedra, faces with four equivalent Ta(2)Ni12 cuboctahedra, and faces with six equivalent Ni(1)Ta4Ni8 cuboctahedra. In the fourth Ni site, Ni(4) is bonded to one Ta(2), three equivalent Ta(1), two equivalent Ni(1), and six equivalent Ni(2) atoms to form distorted NiTa4Ni8 cuboctahedra that share  a cornercorner with one Ni(3)Ta4Ni8 cuboctahedra, corners with two equivalent Ni(4)Ta4Ni8 cuboctahedra, corners with four equivalent Ta(1)Ni12 cuboctahedra, corners with four equivalent Ta(2)Ni12 cuboctahedra, corners with four equivalent Ni(1)Ta4Ni8 cuboctahedra, edges with three equivalent Ni(3)Ta4Ni8 cuboctahedra, edges with four equivalent Ni(4)Ta4Ni8 cuboctahedra, edges with six equivalent Ni(1)Ta4Ni8 cuboctahedra, edges with eight equivalent Ni(2)Ta4Ni8 cuboctahedra, faces with two equivalent Ta(2)Ni12 cuboctahedra, faces with two equivalent Ni(1)Ta4Ni8 cuboctahedra, faces with two equivalent Ni(4)Ta4Ni8 cuboctahedra, faces with three equivalent Ni(3)Ta4Ni8 cuboctahedra, faces with four equivalent Ta(1)Ni12 cuboctahedra, and faces with six equivalent Ni(2)Ta4Ni8 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_TaNi3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.500
_cell_length_b   5.078
_cell_length_c   8.564
_cell_angle_alpha   90.000
_cell_angle_beta   100.877
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   192.188
_cell_formula_units_Z   4
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  0.388  0.750  0.622  1.0
  Ta  Ta1  1  0.612  0.250  0.378  1.0
  Ta  Ta2  1  0.210  0.750  0.128  1.0
  Ta  Ta3  1  0.790  0.250  0.872  1.0
  Ni  Ni4  1  0.294  0.999  0.877  1.0
  Ni  Ni5  1  0.886  0.997  0.627  1.0
  Ni  Ni6  1  0.798  0.750  0.873  1.0
  Ni  Ni7  1  0.114  0.497  0.373  1.0
  Ni  Ni8  1  0.634  0.750  0.376  1.0
  Ni  Ni9  1  0.294  0.501  0.877  1.0
  Ni  Ni10  1  0.366  0.250  0.624  1.0
  Ni  Ni11  1  0.706  0.001  0.123  1.0
  Ni  Ni12  1  0.706  0.499  0.123  1.0
  Ni  Ni13  1  0.114  0.003  0.373  1.0
  Ni  Ni14  1  0.202  0.250  0.127  1.0
  Ni  Ni15  1  0.886  0.503  0.627  1.0
[/CIF]
.