data_YPb2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.29
_cell_length_b   4.29
_cell_length_c   6.05
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   YPb2Se
_chemical_formula_sum   'Y1 Pb2 Se1'
_cell_volume   111.54
_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
  Y  Y3  1  0.15  0.15  0.0  1.0
  Pb  Pb0  1  0.15  0.0  0.03  1.0
  Pb  Pb1  1  0.0  0.15  0.03  1.0
  Se  Se2  1  0.0  0.0  0.0  1.0

data_YPb2Se
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.07
_cell_length_b   6.07
_cell_length_c   6.05
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   YPb2Se
_chemical_formula_sum   'Y2 Pb4 Se2'
_cell_volume   223.08
_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
  Y  Y0  2  0.15  0.0  0.0  1.0
  Pb  Pb1  4  0.07  0.07  0.03  1.0
  Se  Se2  2  0.0  0.0  0.0  1.0

Y Pb Pb Se
Y Pb Pb Se 0 2 o o o 0 1 o o o 1 3 o o o 2 3 o o o 
YPb2Se crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two YPb2Se clusters. Y(1) is bonded in an L-shaped geometry to two equivalent Pb(1) atoms. Both Y(1)-Pb(1) bond lengths are 0.65 Å. Pb(1) is bonded in a distorted L-shaped geometry to one Y(1) and one Se(1) atom. The Pb(1)-Se(1) bond length is 0.65 Å. Se(1) is bonded in an L-shaped geometry to two equivalent Pb(1) atoms.