data_NaPb2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.14
_cell_length_b   4.14
_cell_length_c   6.68
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaPb2Se
_chemical_formula_sum   'Na1 Pb2 Se1'
_cell_volume   114.66
_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
  Pb  Pb1  1  0.07  0.07  0.81  1.0
  Pb  Pb2  1  0.07  0.07  0.87  1.0
  Se  Se3  1  0.0  0.0  0.34  1.0

data_NaPb2Se
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.86
_cell_length_b   5.86
_cell_length_c   6.68
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   NaPb2Se
_chemical_formula_sum   'Na2 Pb4 Se2'
_cell_volume   229.31
_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  2  0.0  0.0  0.0  1.0
  Pb  Pb1  2  0.07  0.0  0.81  1.0
  Pb  Pb2  2  0.07  0.0  0.87  1.0
  Se  Se3  2  0.0  0.0  0.34  1.0

Na Pb Pb Se
NaPb2Se crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two NaPb2Se clusters. Na(1) is bonded in a distorted bent 150 degrees geometry to one Pb(2) and one Se(1) atom. The Na(1)-Pb(2) bond length is 0.94 Å. The Na(1)-Se(1) bond length is 2.27 Å. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a distorted single-bond geometry to one Pb(2) atom. The Pb(1)-Pb(2) bond length is 0.45 Å. In the second Pb site, Pb(2) is bonded in a distorted bent 150 degrees geometry to one Na(1) and one Pb(1) atom. Se(1) is bonded in a distorted single-bond geometry to one Na(1) atom.