data_SiPPb2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.13
_cell_length_b   5.13
_cell_length_c   5.13
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SiPPb2
_chemical_formula_sum   'Si1 P1 Pb2'
_cell_volume   95.58
_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
  Si  Si3  1  0.0  0.0  0.0  1.0
  P  P0  1  0.81  0.81  0.81  1.0
  Pb  Pb1  1  0.44  0.44  0.44  1.0
  Pb  Pb2  1  0.63  0.63  0.63  1.0

data_SiPPb2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.13
_cell_length_b   5.13
_cell_length_c   12.57
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   SiPPb2
_chemical_formula_sum   'Si3 P3 Pb6'
_cell_volume   286.75
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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
  Si  Si0  3  0.0  0.0  0.0  1.0
  P  P1  3  0.0  0.0  0.19  1.0
  Pb  Pb2  3  0.0  0.0  0.37  1.0
  Pb  Pb3  3  0.0  0.0  0.56  1.0

Si P Pb Pb
Si P Pb Pb 0 1 - - - 0 3 - - o 0 3 - o - 0 3 o - - 1 3 o o o 1 2 + o o 1 2 o + o 1 2 o o + 2 3 o o o 
Pb2SiP crystallizes in the trigonal R3m space group. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a 7-coordinate geometry to one Pb(2), three equivalent Si(1), and three equivalent P(1) atoms. The Pb(1)-Pb(2) bond length is 2.33 Å. All Pb(1)-Si(1) bond lengths are 3.27 Å. All Pb(1)-P(1) bond lengths are 3.00 Å. In the second Pb site, Pb(2) is bonded to one Pb(1), three equivalent Si(1), and one P(1) atom to form distorted corner-sharing PbSi3PPb trigonal bipyramids. All Pb(2)-Si(1) bond lengths are 3.00 Å. The Pb(2)-P(1) bond length is 2.33 Å. Si(1) is bonded in a 7-coordinate geometry to three equivalent Pb(1), three equivalent Pb(2), and one P(1) atom. The Si(1)-P(1) bond length is 2.33 Å. P(1) is bonded in a distorted linear geometry to one Pb(2), three equivalent Pb(1), and one Si(1) atom.