The crystal structure described by Pb4GeTe5 is Caswellsilverite-like structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded to three equivalent Te(1) and three equivalent Te(3) atoms to form PbTe6 octahedra that share corners with three equivalent Pb(2)Te6 octahedra, corners with three equivalent Ge(1)Te6 octahedra, edges with three equivalent Pb(2)Te6 octahedra, edges with three equivalent Ge(1)Te6 octahedra, and edges with six equivalent Pb(1)Te6 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. In the second Pb site, Pb(2) is bonded to three equivalent Te(2) and three equivalent Te(3) atoms to form a mixture of corner and edge-sharing PbTe6 octahedra. The corner-sharing octahedra are not tilted. Ge(1) is bonded to six equivalent Te(1) atoms to form GeTe6 octahedra that share corners with six equivalent Pb(1)Te6 octahedra, edges with six equivalent Pb(1)Te6 octahedra, and edges with six equivalent Ge(1)Te6 octahedra. The corner-sharing octahedral tilt angles are 6°. There are three inequivalent Te sites. In the first Te site, Te(1) is bonded to three equivalent Pb(1) and three equivalent Ge(1) atoms to form TeGe3Pb3 octahedra that share corners with three equivalent Te(1)Ge3Pb3 octahedra, corners with three equivalent Te(3)Pb6 octahedra, edges with three equivalent Te(3)Pb6 octahedra, and edges with nine equivalent Te(1)Ge3Pb3 octahedra. The corner-sharing octahedra are not tilted. In the second Te site, Te(2) is bonded to six equivalent Pb(2) atoms to form a mixture of corner and edge-sharing TePb6 octahedra. The corner-sharing octahedra are not tilted. In the third Te site, Te(3) is bonded to three equivalent Pb(1) and three equivalent Pb(2) atoms to form TePb6 octahedra that share corners with three equivalent Te(1)Ge3Pb3 octahedra, corners with three equivalent Te(2)Pb6 octahedra, edges with three equivalent Te(1)Ge3Pb3 octahedra, edges with three equivalent Te(2)Pb6 octahedra, and edges with six equivalent Te(3)Pb6 octahedra. The corner-sharing octahedra are not tilted. is represented by the Crystallographic Information File (CIF) [CIF]
data_GeTe5Pb4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   18.720
_cell_length_b   18.720
_cell_length_c   18.720
_cell_angle_alpha   14.055
_cell_angle_beta   14.055
_cell_angle_gamma   14.055
_symmetry_Int_Tables_number   1
_cell_volume   336.737
_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
  Ge  Ge0  1  0.000  0.000  0.000  1.0
  Te  Te1  1  0.695  0.695  0.695  1.0
  Te  Te2  1  0.500  0.500  0.500  1.0
  Te  Te3  1  0.098  0.098  0.098  1.0
  Te  Te4  1  0.305  0.305  0.305  1.0
  Te  Te5  1  0.902  0.902  0.902  1.0
  Pb  Pb6  1  0.604  0.604  0.604  1.0
  Pb  Pb7  1  0.201  0.201  0.201  1.0
  Pb  Pb8  1  0.799  0.799  0.799  1.0
  Pb  Pb9  1  0.396  0.396  0.396  1.0
[/CIF]
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The crystal structure described by Pb4GeTe5 is Caswellsilverite-like structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded to three equivalent Te(1) and three equivalent Te(3) atoms to form PbTe6 octahedra that share corners with three equivalent Pb(2)Te6 octahedra, corners with three equivalent Ge(1)Te6 octahedra, edges with three equivalent Pb(2)Te6 octahedra, edges with three equivalent Ge(1)Te6 octahedra, and edges with six equivalent Pb(1)Te6 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. In the second Pb site, Pb(2) is bonded to three equivalent Te(2) and three equivalent Te(3) atoms to form a mixture of corner and edge-sharing PbTe6 octahedra. The corner-sharing octahedra are not tilted. Ge(1) is bonded to six equivalent Te(1) atoms to form GeTe6 octahedra that share corners with six equivalent Pb(1)Te6 octahedra, edges with six equivalent Pb(1)Te6 octahedra, and edges with six equivalent Ge(1)Te6 octahedra. The corner-sharing octahedral tilt angles are 6°. There are three inequivalent Te sites. In the first Te site, Te(1) is bonded to three equivalent Pb(1) and three equivalent Ge(1) atoms to form TeGe3Pb3 octahedra that share corners with three equivalent Te(1)Ge3Pb3 octahedra, corners with three equivalent Te(3)Pb6 octahedra, edges with three equivalent Te(3)Pb6 octahedra, and edges with nine equivalent Te(1)Ge3Pb3 octahedra. The corner-sharing octahedra are not tilted. In the second Te site, Te(2) is bonded to six equivalent Pb(2) atoms to form a mixture of corner and edge-sharing TePb6 octahedra. The corner-sharing octahedra are not tilted. In the third Te site, Te(3) is bonded to three equivalent Pb(1) and three equivalent Pb(2) atoms to form TePb6 octahedra that share corners with three equivalent Te(1)Ge3Pb3 octahedra, corners with three equivalent Te(2)Pb6 octahedra, edges with three equivalent Te(1)Ge3Pb3 octahedra, edges with three equivalent Te(2)Pb6 octahedra, and edges with six equivalent Te(3)Pb6 octahedra. The corner-sharing octahedra are not tilted. is represented by the Crystallographic Information File (CIF) [CIF]
data_GeTe5Pb4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   18.720
_cell_length_b   18.720
_cell_length_c   18.720
_cell_angle_alpha   14.055
_cell_angle_beta   14.055
_cell_angle_gamma   14.055
_symmetry_Int_Tables_number   1
_cell_volume   336.737
_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
  Ge  Ge0  1  0.000  0.000  0.000  1.0
  Te  Te1  1  0.695  0.695  0.695  1.0
  Te  Te2  1  0.500  0.500  0.500  1.0
  Te  Te3  1  0.098  0.098  0.098  1.0
  Te  Te4  1  0.305  0.305  0.305  1.0
  Te  Te5  1  0.902  0.902  0.902  1.0
  Pb  Pb6  1  0.604  0.604  0.604  1.0
  Pb  Pb7  1  0.201  0.201  0.201  1.0
  Pb  Pb8  1  0.799  0.799  0.799  1.0
  Pb  Pb9  1  0.396  0.396  0.396  1.0
[/CIF]
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