data_NaTbNb2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.96
_cell_length_b   4.96
_cell_length_c   4.96
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaTbNb2
_chemical_formula_sum   'Na1 Tb1 Nb2'
_cell_volume   86.51
_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
  Na  Na0  1  0.0  0.0  0.0  1.0
  Tb  Tb3  1  0.51  0.51  0.51  1.0
  Nb  Nb1  1  0.27  0.27  0.27  1.0
  Nb  Nb2  1  0.76  0.76  0.76  1.0

data_NaTbNb2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.96
_cell_length_b   4.96
_cell_length_c   12.16
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   NaTbNb2
_chemical_formula_sum   'Na3 Tb3 Nb6'
_cell_volume   259.52
_cell_formula_units_Z   3
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
  Na  Na0  3  0.0  0.0  0.0  1.0
  Tb  Tb1  3  0.0  0.0  0.49  1.0
  Nb  Nb2  3  0.0  0.0  0.24  1.0
  Nb  Nb3  3  0.0  0.0  0.73  1.0

Na Tb Nb Nb
Na Tb Nb Nb 0 3 - - - 0 3 - - o 0 3 o - - 0 3 - o - 0 1 - - o 0 1 - o - 0 1 - o o 0 1 o - - 0 1 o - o 0 1 o o - 0 2 - o o 0 2 o - o 0 2 o o - 0 2 o o o 1 2 o o o 1 2 o o + 1 2 + o o 1 2 o + o 1 3 o - o 1 3 - o o 1 3 o o - 1 3 o o o 2 3 - - o 2 3 - o - 2 3 - o o 2 3 o - - 2 3 o - o 2 3 o o - 
NaTbNb2 is Heusler structured and crystallizes in the trigonal R3m space group. Na(1) is bonded in a distorted body-centered cubic geometry to four equivalent Nb(1) and four equivalent Nb(2) atoms. There are three shorter (2.98 Å) and one longer (3.23 Å) Na(1)-Nb(1) bond length. There is one shorter (2.98 Å) and three longer (3.06 Å) Na(1)-Nb(2) bond lengths. Tb(1) is bonded in a body-centered cubic geometry to four equivalent Nb(1) and four equivalent Nb(2) atoms. There is one shorter (2.98 Å) and three longer (3.06 Å) Tb(1)-Nb(1) bond lengths. There is one shorter (2.98 Å) and three longer (3.06 Å) Tb(1)-Nb(2) bond lengths. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a body-centered cubic geometry to four equivalent Na(1) and four equivalent Tb(1) atoms. In the second Nb site, Nb(2) is bonded in a body-centered cubic geometry to four equivalent Na(1) and four equivalent Tb(1) atoms.