The material structure described by Ta4Ni2C crystallizes in the cubic Fd-3m space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a distorted hexagonal planar geometry to six equivalent Ni(1) atoms. In the second Ta site, Ta(2) is bonded in a distorted bent 150 degrees geometry to four equivalent Ni(1) and two equivalent C(1) atoms. Ni(1) is bonded in a 12-coordinate geometry to three equivalent Ta(1), six equivalent Ta(2), and three equivalent Ni(1) atoms. C(1) is bonded to six equivalent Ta(2) atoms to form corner-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 36°. is represented by the CIF file [CIF]
data_Ta4Ni2C
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.219
_cell_length_b   8.219
_cell_length_c   8.219
_cell_angle_alpha   60.002
_cell_angle_beta   60.002
_cell_angle_gamma   60.002
_symmetry_Int_Tables_number   1
_cell_volume   392.620
_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  0.625  0.625  0.625  1.0
  Ta  Ta1  1  0.625  0.625  0.125  1.0
  Ta  Ta2  1  0.125  0.625  0.625  1.0
  Ta  Ta3  1  0.625  0.125  0.625  1.0
  Ta  Ta4  1  0.433  0.067  0.067  1.0
  Ta  Ta5  1  0.067  0.433  0.433  1.0
  Ta  Ta6  1  0.067  0.433  0.067  1.0
  Ta  Ta7  1  0.067  0.067  0.433  1.0
  Ta  Ta8  1  0.433  0.067  0.433  1.0
  Ta  Ta9  1  0.433  0.433  0.067  1.0
  Ta  Ta10  1  0.183  0.817  0.183  1.0
  Ta  Ta11  1  0.817  0.183  0.817  1.0
  Ta  Ta12  1  0.817  0.183  0.183  1.0
  Ta  Ta13  1  0.183  0.183  0.817  1.0
  Ta  Ta14  1  0.183  0.817  0.817  1.0
  Ta  Ta15  1  0.817  0.817  0.183  1.0
  Ni  Ni16  1  0.830  0.830  0.830  1.0
  Ni  Ni17  1  0.830  0.830  0.509  1.0
  Ni  Ni18  1  0.509  0.830  0.830  1.0
  Ni  Ni19  1  0.830  0.509  0.830  1.0
  Ni  Ni20  1  0.420  0.420  0.420  1.0
  Ni  Ni21  1  0.420  0.420  0.741  1.0
  Ni  Ni22  1  0.420  0.741  0.420  1.0
  Ni  Ni23  1  0.741  0.420  0.420  1.0
  C  C24  1  0.125  0.125  0.125  1.0
  C  C25  1  0.125  0.125  0.625  1.0
  C  C26  1  0.625  0.125  0.125  1.0
  C  C27  1  0.125  0.625  0.125  1.0
[/CIF]
.
The material structure described by Ta4Ni2C crystallizes in the cubic Fd-3m space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a distorted hexagonal planar geometry to six equivalent Ni(1) atoms. In the second Ta site, Ta(2) is bonded in a distorted bent 150 degrees geometry to four equivalent Ni(1) and two equivalent C(1) atoms. Ni(1) is bonded in a 12-coordinate geometry to three equivalent Ta(1), six equivalent Ta(2), and three equivalent Ni(1) atoms. C(1) is bonded to six equivalent Ta(2) atoms to form corner-sharing CTa6 octahedra. The corner-sharing octahedral tilt angles are 36°. is represented by the CIF file [CIF]
data_Ta4Ni2C
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.219
_cell_length_b   8.219
_cell_length_c   8.219
_cell_angle_alpha   60.002
_cell_angle_beta   60.002
_cell_angle_gamma   60.002
_symmetry_Int_Tables_number   1
_cell_volume   392.620
_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  0.625  0.625  0.625  1.0
  Ta  Ta1  1  0.625  0.625  0.125  1.0
  Ta  Ta2  1  0.125  0.625  0.625  1.0
  Ta  Ta3  1  0.625  0.125  0.625  1.0
  Ta  Ta4  1  0.433  0.067  0.067  1.0
  Ta  Ta5  1  0.067  0.433  0.433  1.0
  Ta  Ta6  1  0.067  0.433  0.067  1.0
  Ta  Ta7  1  0.067  0.067  0.433  1.0
  Ta  Ta8  1  0.433  0.067  0.433  1.0
  Ta  Ta9  1  0.433  0.433  0.067  1.0
  Ta  Ta10  1  0.183  0.817  0.183  1.0
  Ta  Ta11  1  0.817  0.183  0.817  1.0
  Ta  Ta12  1  0.817  0.183  0.183  1.0
  Ta  Ta13  1  0.183  0.183  0.817  1.0
  Ta  Ta14  1  0.183  0.817  0.817  1.0
  Ta  Ta15  1  0.817  0.817  0.183  1.0
  Ni  Ni16  1  0.830  0.830  0.830  1.0
  Ni  Ni17  1  0.830  0.830  0.509  1.0
  Ni  Ni18  1  0.509  0.830  0.830  1.0
  Ni  Ni19  1  0.830  0.509  0.830  1.0
  Ni  Ni20  1  0.420  0.420  0.420  1.0
  Ni  Ni21  1  0.420  0.420  0.741  1.0
  Ni  Ni22  1  0.420  0.741  0.420  1.0
  Ni  Ni23  1  0.741  0.420  0.420  1.0
  C  C24  1  0.125  0.125  0.125  1.0
  C  C25  1  0.125  0.125  0.625  1.0
  C  C26  1  0.625  0.125  0.125  1.0
  C  C27  1  0.125  0.625  0.125  1.0
[/CIF]
.