data_Na2SiBi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.78
_cell_length_b   5.78
_cell_length_c   5.78
_cell_angle_alpha   134.96
_cell_angle_beta   134.96
_cell_angle_gamma   65.58
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2SiBi
_chemical_formula_sum   'Na2 Si1 Bi1'
_cell_volume   95.42
_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  0.22  0.43  1.0
  Na  Na2  1  0.22  0.0  0.43  1.0
  Si  Si3  1  0.0  0.0  0.0  1.0
  Bi  Bi0  1  0.0  0.0  0.86  1.0

data_Na2SiBi
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.27
_cell_length_b   6.27
_cell_length_c   5.78
_cell_angle_alpha   90.0
_cell_angle_beta   122.79
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Na2SiBi
_chemical_formula_sum   'Na4 Si2 Bi2'
_cell_volume   190.84
_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  0.39  0.39  0.22  1.0
  Si  Si1  2  0.0  0.0  0.0  1.0
  Bi  Bi2  2  0.0  0.0  0.86  1.0

Na Na Si Bi
Na Na Si Bi 0 1 o o o 2 3 o o - 
Na2SiBi is Indium-like structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Na2SiBi clusters. Na(1) is bonded in a 2-coordinate geometry to one Na(1) and one Si(1) atom. The Na(1)-Na(1) bond length is 1.35 Å. The Na(1)-Si(1) bond length is 1.84 Å. Si(1) is bonded in a 3-coordinate geometry to two equivalent Na(1) and one Bi(1) atom. The Si(1)-Bi(1) bond length is 0.80 Å. Bi(1) is bonded in a single-bond geometry to one Si(1) atom.