data_SrPb2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.81
_cell_length_b   3.81
_cell_length_c   8.71
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   91.89
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrPb2Se
_chemical_formula_sum   'Sr1 Pb2 Se1'
_cell_volume   126.32
_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
  Sr  Sr3  1  0.65  0.0  0.68  1.0
  Pb  Pb0  1  0.0  0.0  0.58  1.0
  Pb  Pb1  1  0.65  0.0  0.4  1.0
  Se  Se2  1  0.0  0.0  0.11  1.0

data_SrPb2Se
_symmetry_space_group_name_H-M   Pm
_cell_length_a   3.81
_cell_length_b   3.81
_cell_length_c   8.71
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   6
_chemical_formula_structural   SrPb2Se
_chemical_formula_sum   'Sr1 Pb2 Se1'
_cell_volume   126.39
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '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
  Sr  Sr0  1  0.65  0.0  0.68  1.0
  Pb  Pb1  1  0.0  0.0  0.58  1.0
  Pb  Pb2  1  0.65  0.0  0.4  1.0
  Se  Se3  1  0.0  0.0  0.11  1.0

Sr Pb Pb Se
SrPb2Se crystallizes in the monoclinic Pm space group. The structure is zero-dimensional and consists of one SrPb2Se cluster. Sr(1) is bonded in a 1-coordinate geometry to one Pb(1) and one Pb(2) atom. The Sr(1)-Pb(1) bond length is 1.60 Å. The Sr(1)-Pb(2) bond length is 2.44 Å. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a 1-coordinate geometry to one Sr(1) and one Pb(2) atom. The Pb(1)-Pb(2) bond length is 2.05 Å. In the second Pb site, Pb(2) is bonded in a 3-coordinate geometry to one Sr(1), one Pb(1), and one Se(1) atom. The Pb(2)-Se(1) bond length is 2.85 Å. Se(1) is bonded in a single-bond geometry to one Pb(2) atom.