data_Na2NbBi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.43
_cell_length_b   6.43
_cell_length_c   6.43
_cell_angle_alpha   142.24
_cell_angle_beta   142.24
_cell_angle_gamma   54.47
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2NbBi
_chemical_formula_sum   'Na2 Nb1 Bi1'
_cell_volume   99.01
_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  Na1  1  0.0  0.08  0.86  1.0
  Na  Na2  1  0.08  0.0  0.86  1.0
  Nb  Nb3  1  0.0  0.0  0.0  1.0
  Bi  Bi0  1  0.0  0.0  0.72  1.0

data_Na2NbBi
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.89
_cell_length_b   5.89
_cell_length_c   6.43
_cell_angle_alpha   90.0
_cell_angle_beta   117.24
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Na2NbBi
_chemical_formula_sum   'Na4 Nb2 Bi2'
_cell_volume   198.02
_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
  Na  Na0  4  0.32  0.46  0.78  1.0
  Nb  Nb1  2  0.0  0.0  0.0  1.0
  Bi  Bi2  2  0.22  0.5  0.72  1.0

Na Na Nb Bi
Na Na Nb Bi 0 1 o o o 0 2 o o + 0 3 o o o 1 2 o o + 1 3 o o o 
Na2NbBi crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Na2NbBi clusters. Na(1) is bonded in a 3-coordinate geometry to one Na(1), one Nb(1), and one Bi(1) atom. The Na(1)-Na(1) bond length is 0.48 Å. The Na(1)-Nb(1) bond length is 1.36 Å. The Na(1)-Bi(1) bond length is 0.59 Å. Nb(1) is bonded in a 2-coordinate geometry to two equivalent Na(1) atoms. Bi(1) is bonded in a 2-coordinate geometry to two equivalent Na(1) atoms.