data_NbNi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.79
_cell_length_b   4.79
_cell_length_c   4.79
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NbNi2
_chemical_formula_sum   'Nb2 Ni4'
_cell_volume   77.77
_cell_formula_units_Z   2
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
  Nb  Nb0  1  0.69  0.69  0.69  1.0
  Nb  Nb1  1  0.0  0.0  0.0  1.0
  Ni  Ni2  1  0.23  0.54  0.54  1.0
  Ni  Ni3  1  0.54  0.23  0.54  1.0
  Ni  Ni4  1  0.54  0.54  0.23  1.0
  Ni  Ni5  1  0.23  0.23  0.23  1.0

data_NbNi2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.79
_cell_length_b   4.79
_cell_length_c   11.74
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   NbNi2
_chemical_formula_sum   'Nb6 Ni12'
_cell_volume   233.31
_cell_formula_units_Z   6
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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
  Nb  Nb0  3  0.0  0.0  0.0  1.0
  Nb  Nb1  3  0.0  0.0  0.31  1.0
  Ni  Ni2  9  0.2  0.1  0.56  1.0
  Ni  Ni3  3  0.0  0.0  0.77  1.0

Nb Nb Ni Ni Ni Ni
Nb Nb Ni Ni Ni Ni 0 4 o o + 0 2 + o o 0 3 o + o 0 1 + + o 0 1 + o + 0 1 o + + 0 5 + o o 0 5 o + o 0 5 o o + 1 5 o - o 1 5 - o o 1 5 o o - 1 5 o o o 1 4 - - o 1 4 - o o 1 4 o - o 1 3 - o - 1 3 - o o 1 3 o o - 1 2 o - - 1 2 o - o 1 2 o o - 2 3 o o o 2 4 o o o 2 5 o + o 2 5 o o + 2 5 o o o 3 4 o o o 3 5 + o o 3 5 o o + 3 5 o o o 4 5 + o o 4 5 o + o 4 5 o o o 
Ni2Nb crystallizes in the trigonal R3m space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Nb(2), three equivalent Ni(1), and three equivalent Ni(2) atoms. All Nb(1)-Nb(2) bond lengths are 2.78 Å. All Nb(1)-Ni(1) bond lengths are 2.13 Å. All Nb(1)-Ni(2) bond lengths are 3.14 Å. In the second Nb site, Nb(2) is bonded in a 16-coordinate geometry to three equivalent Nb(1), four equivalent Ni(2), and nine equivalent Ni(1) atoms. There is one shorter (2.76 Å) and three longer (3.00 Å) Nb(2)-Ni(2) bond lengths. There are six shorter (2.75 Å) and three longer (3.29 Å) Nb(2)-Ni(1) bond lengths. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 3-coordinate geometry to one Nb(1), three equivalent Nb(2), two equivalent Ni(1), and three equivalent Ni(2) atoms. Both Ni(1)-Ni(1) bond lengths are 1.47 Å. There is one shorter (2.54 Å) and two longer (2.89 Å) Ni(1)-Ni(2) bond lengths. In the second Ni site, Ni(2) is bonded in a 16-coordinate geometry to three equivalent Nb(1), four equivalent Nb(2), and nine equivalent Ni(1) atoms.