The material structure described by Na4Ge2Te5 crystallizes in the triclinic P-1 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded to one Te(1), one Te(2), two equivalent Te(3), and two equivalent Te(4) atoms to form distorted NaTe6 octahedra that share  a cornercorner with one Na(2)Te6 octahedra,  a cornercorner with one Na(4)Te6 octahedra, corners with two equivalent Na(3)Te6 octahedra, corners with three equivalent Ge(1)GeTe3 tetrahedra, corners with three equivalent Ge(2)GeTe3 tetrahedra, edges with two equivalent Na(1)Te6 octahedra, edges with two equivalent Na(4)Te6 octahedra, edges with three equivalent Na(2)Te6 octahedra, and edges with three equivalent Na(3)Te6 octahedra. The corner-sharing octahedral tilt angles range from 3-15°. In the second Na site, Na(2) is bonded to one Te(2), one Te(3), one Te(4), one Te(5), and two equivalent Te(1) atoms to form NaTe6 octahedra that share  a cornercorner with one Na(1)Te6 octahedra, corners with two equivalent Na(3)Te6 octahedra, corners with two equivalent Na(4)Te6 octahedra,  a cornercorner with one Ge(2)GeTe3 tetrahedra,  an edgeedge with one Na(2)Te6 octahedra, edges with two equivalent Na(3)Te6 octahedra, edges with three equivalent Na(1)Te6 octahedra, edges with three equivalent Na(4)Te6 octahedra,  an edgeedge with one Ge(2)GeTe3 tetrahedra, and edges with two equivalent Ge(1)GeTe3 tetrahedra. The corner-sharing octahedral tilt angles range from 3-11°. In the third Na site, Na(3) is bonded to one Te(4), one Te(5), two equivalent Te(2), and two equivalent Te(3) atoms to form NaTe6 octahedra that share  a cornercorner with one Na(4)Te6 octahedra, corners with two equivalent Na(1)Te6 octahedra, corners with two equivalent Na(2)Te6 octahedra,  a cornercorner with one Ge(2)GeTe3 tetrahedra, corners with two equivalent Ge(1)GeTe3 tetrahedra, edges with two equivalent Na(2)Te6 octahedra, edges with two equivalent Na(3)Te6 octahedra, edges with two equivalent Na(4)Te6 octahedra, edges with three equivalent Na(1)Te6 octahedra, and edges with two equivalent Ge(2)GeTe3 tetrahedra. The corner-sharing octahedral tilt angles range from 1-15°. In the fourth Na site, Na(4) is bonded to one Te(2), one Te(4), two equivalent Te(1), and two equivalent Te(5) atoms to form distorted NaTe6 octahedra that share  a cornercorner with one Na(1)Te6 octahedra,  a cornercorner with one Na(3)Te6 octahedra, corners with two equivalent Na(2)Te6 octahedra, corners with three equivalent Ge(1)GeTe3 tetrahedra, corners with three equivalent Ge(2)GeTe3 tetrahedra, edges with two equivalent Na(1)Te6 octahedra, edges with two equivalent Na(3)Te6 octahedra, edges with two equivalent Na(4)Te6 octahedra, edges with three equivalent Na(2)Te6 octahedra, and  an edgeedge with one Ge(1)GeTe3 tetrahedra. The corner-sharing octahedral tilt angles range from 1-11°. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one Ge(2), one Te(1), one Te(4), and one Te(5) atom to form GeGeTe3 tetrahedra that share  a cornercorner with one Te(5)Na4Ge2 octahedra,  a cornercorner with one Te(2)Na5Ge octahedra,  a cornercorner with one Te(3)Na5Ge octahedra, corners with two equivalent Na(3)Te6 octahedra, corners with three equivalent Na(1)Te6 octahedra, corners with three equivalent Na(4)Te6 octahedra,  a cornercorner with one Ge(2)GeTe3 tetrahedra,  an edgeedge with one Na(4)Te6 octahedra, and edges with two equivalent Na(2)Te6 octahedra. The corner-sharing octahedral tilt angles range from 19-87°. In the second Ge site, Ge(2) is bonded to one Ge(1), one Te(2), one Te(3), and one Te(5) atom to form GeGeTe3 tetrahedra that share  a cornercorner with one Na(2)Te6 octahedra,  a cornercorner with one Na(3)Te6 octahedra,  a cornercorner with one Te(5)Na4Ge2 octahedra,  a cornercorner with one Te(1)Na5Ge octahedra,  a cornercorner with one Te(4)Na5Ge octahedra, corners with three equivalent Na(1)Te6 octahedra, corners with three equivalent Na(4)Te6 octahedra,  a cornercorner with one Ge(1)GeTe3 tetrahedra,  an edgeedge with one Na(2)Te6 octahedra, and edges with two equivalent Na(3)Te6 octahedra. The corner-sharing octahedral tilt angles range from 16-85°. There are five inequivalent Te sites. In the first Te site, Te(1) is bonded to one Na(1), two equivalent Na(2), two equivalent Na(4), and one Ge(1) atom to form TeNa5Ge octahedra that share  a cornercorner with one Te(2)Na5Ge octahedra,  a cornercorner with one Te(4)Na5Ge octahedra, corners with two equivalent Te(3)Na5Ge octahedra, corners with three equivalent Te(5)Na4Ge2 octahedra,  a cornercorner with one Ge(2)GeTe3 tetrahedra,  an edgeedge with one Te(3)Na5Ge octahedra, edges with two equivalent Te(5)Na4Ge2 octahedra, edges with two equivalent Te(1)Na5Ge octahedra, edges with two equivalent Te(2)Na5Ge octahedra, and edges with three equivalent Te(4)Na5Ge octahedra. The corner-sharing octahedral tilt angles range from 5-86°. In the second Te site, Te(2) is bonded to one Na(1), one Na(2), one Na(4), two equivalent Na(3), and one Ge(2) atom to form TeNa5Ge octahedra that share  a cornercorner with one Te(1)Na5Ge octahedra, corners with two equivalent Te(5)Na4Ge2 octahedra, corners with two equivalent Te(3)Na5Ge octahedra, corners with two equivalent Te(4)Na5Ge octahedra,  a cornercorner with one Ge(1)GeTe3 tetrahedra,  an edgeedge with one Te(2)Na5Ge octahedra, edges with two equivalent Te(5)Na4Ge2 octahedra, edges with two equivalent Te(1)Na5Ge octahedra, edges with two equivalent Te(4)Na5Ge octahedra, and edges with three equivalent Te(3)Na5Ge octahedra. The corner-sharing octahedral tilt angles range from 6-87°. In the third Te site, Te(3) is bonded to one Na(2), two equivalent Na(1), two equivalent Na(3), and one Ge(2) atom to form TeNa5Ge octahedra that share corners with two equivalent Te(1)Na5Ge octahedra, corners with two equivalent Te(2)Na5Ge octahedra, corners with three equivalent Te(4)Na5Ge octahedra,  a cornercorner with one Ge(1)GeTe3 tetrahedra,  an edgeedge with one Te(1)Na5Ge octahedra, edges with two equivalent Te(5)Na4Ge2 octahedra, edges with two equivalent Te(3)Na5Ge octahedra, edges with two equivalent Te(4)Na5Ge octahedra, and edges with three equivalent Te(2)Na5Ge octahedra. The corner-sharing octahedral tilt angles range from 6-86°. In the fourth Te site, Te(4) is bonded to one Na(2), one Na(3), one Na(4), two equivalent Na(1), and one Ge(1) atom to form distorted TeNa5Ge octahedra that share  a cornercorner with one Te(5)Na4Ge2 octahedra,  a cornercorner with one Te(1)Na5Ge octahedra, corners with two equivalent Te(2)Na5Ge octahedra, corners with three equivalent Te(3)Na5Ge octahedra,  a cornercorner with one Ge(2)GeTe3 tetrahedra,  an edgeedge with one Te(4)Na5Ge octahedra, edges with two equivalent Te(5)Na4Ge2 octahedra, edges with two equivalent Te(2)Na5Ge octahedra, edges with two equivalent Te(3)Na5Ge octahedra, and edges with three equivalent Te(1)Na5Ge octahedra. The corner-sharing octahedral tilt angles range from 6-87°. In the fifth Te site, Te(5) is bonded to one Na(2), one Na(3), two equivalent Na(4), one Ge(1), and one Ge(2) atom to form distorted TeNa4Ge2 octahedra that share  a cornercorner with one Te(4)Na5Ge octahedra, corners with two equivalent Te(2)Na5Ge octahedra, corners with three equivalent Te(1)Na5Ge octahedra,  a cornercorner with one Ge(1)GeTe3 tetrahedra,  a cornercorner with one Ge(2)GeTe3 tetrahedra,  an edgeedge with one Te(5)Na4Ge2 octahedra, edges with two equivalent Te(1)Na5Ge octahedra, edges with two equivalent Te(2)Na5Ge octahedra, edges with two equivalent Te(3)Na5Ge octahedra, and edges with two equivalent Te(4)Na5Ge octahedra. The corner-sharing octahedral tilt angles range from 5-85°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na4Ge2Te5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.947
_cell_length_b   9.622
_cell_length_c   10.707
_cell_angle_alpha   68.665
_cell_angle_beta   70.809
_cell_angle_gamma   68.013
_symmetry_Int_Tables_number   1
_cell_volume   689.331
_cell_formula_units_Z   2
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  0.270  0.440  0.427  1.0
  Na  Na1  1  0.730  0.560  0.573  1.0
  Na  Na2  1  0.873  0.368  0.189  1.0
  Na  Na3  1  0.127  0.632  0.811  1.0
  Na  Na4  1  0.679  0.048  0.586  1.0
  Na  Na5  1  0.321  0.952  0.414  1.0
  Na  Na6  1  0.464  0.736  0.019  1.0
  Na  Na7  1  0.536  0.264  0.981  1.0
  Ge  Ge8  1  0.895  0.763  0.145  1.0
  Ge  Ge9  1  0.105  0.237  0.855  1.0
  Ge  Ge10  1  0.915  0.940  0.254  1.0
  Ge  Ge11  1  0.085  0.060  0.746  1.0
  Te  Te12  1  0.810  0.469  0.873  1.0
  Te  Te13  1  0.190  0.531  0.127  1.0
  Te  Te14  1  0.395  0.844  0.719  1.0
  Te  Te15  1  0.605  0.156  0.281  1.0
  Te  Te16  1  0.987  0.231  0.520  1.0
  Te  Te17  1  0.013  0.769  0.480  1.0
  Te  Te18  1  0.395  0.329  0.715  1.0
  Te  Te19  1  0.605  0.671  0.285  1.0
  Te  Te20  1  0.806  0.942  0.906  1.0
  Te  Te21  1  0.194  0.058  0.094  1.0
[/CIF]
.
The material structure described by Na4Ge2Te5 crystallizes in the triclinic P-1 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded to one Te(1), one Te(2), two equivalent Te(3), and two equivalent Te(4) atoms to form distorted NaTe6 octahedra that share  a cornercorner with one Na(2)Te6 octahedra,  a cornercorner with one Na(4)Te6 octahedra, corners with two equivalent Na(3)Te6 octahedra, corners with three equivalent Ge(1)GeTe3 tetrahedra, corners with three equivalent Ge(2)GeTe3 tetrahedra, edges with two equivalent Na(1)Te6 octahedra, edges with two equivalent Na(4)Te6 octahedra, edges with three equivalent Na(2)Te6 octahedra, and edges with three equivalent Na(3)Te6 octahedra. The corner-sharing octahedral tilt angles range from 3-15°. In the second Na site, Na(2) is bonded to one Te(2), one Te(3), one Te(4), one Te(5), and two equivalent Te(1) atoms to form NaTe6 octahedra that share  a cornercorner with one Na(1)Te6 octahedra, corners with two equivalent Na(3)Te6 octahedra, corners with two equivalent Na(4)Te6 octahedra,  a cornercorner with one Ge(2)GeTe3 tetrahedra,  an edgeedge with one Na(2)Te6 octahedra, edges with two equivalent Na(3)Te6 octahedra, edges with three equivalent Na(1)Te6 octahedra, edges with three equivalent Na(4)Te6 octahedra,  an edgeedge with one Ge(2)GeTe3 tetrahedra, and edges with two equivalent Ge(1)GeTe3 tetrahedra. The corner-sharing octahedral tilt angles range from 3-11°. In the third Na site, Na(3) is bonded to one Te(4), one Te(5), two equivalent Te(2), and two equivalent Te(3) atoms to form NaTe6 octahedra that share  a cornercorner with one Na(4)Te6 octahedra, corners with two equivalent Na(1)Te6 octahedra, corners with two equivalent Na(2)Te6 octahedra,  a cornercorner with one Ge(2)GeTe3 tetrahedra, corners with two equivalent Ge(1)GeTe3 tetrahedra, edges with two equivalent Na(2)Te6 octahedra, edges with two equivalent Na(3)Te6 octahedra, edges with two equivalent Na(4)Te6 octahedra, edges with three equivalent Na(1)Te6 octahedra, and edges with two equivalent Ge(2)GeTe3 tetrahedra. The corner-sharing octahedral tilt angles range from 1-15°. In the fourth Na site, Na(4) is bonded to one Te(2), one Te(4), two equivalent Te(1), and two equivalent Te(5) atoms to form distorted NaTe6 octahedra that share  a cornercorner with one Na(1)Te6 octahedra,  a cornercorner with one Na(3)Te6 octahedra, corners with two equivalent Na(2)Te6 octahedra, corners with three equivalent Ge(1)GeTe3 tetrahedra, corners with three equivalent Ge(2)GeTe3 tetrahedra, edges with two equivalent Na(1)Te6 octahedra, edges with two equivalent Na(3)Te6 octahedra, edges with two equivalent Na(4)Te6 octahedra, edges with three equivalent Na(2)Te6 octahedra, and  an edgeedge with one Ge(1)GeTe3 tetrahedra. The corner-sharing octahedral tilt angles range from 1-11°. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one Ge(2), one Te(1), one Te(4), and one Te(5) atom to form GeGeTe3 tetrahedra that share  a cornercorner with one Te(5)Na4Ge2 octahedra,  a cornercorner with one Te(2)Na5Ge octahedra,  a cornercorner with one Te(3)Na5Ge octahedra, corners with two equivalent Na(3)Te6 octahedra, corners with three equivalent Na(1)Te6 octahedra, corners with three equivalent Na(4)Te6 octahedra,  a cornercorner with one Ge(2)GeTe3 tetrahedra,  an edgeedge with one Na(4)Te6 octahedra, and edges with two equivalent Na(2)Te6 octahedra. The corner-sharing octahedral tilt angles range from 19-87°. In the second Ge site, Ge(2) is bonded to one Ge(1), one Te(2), one Te(3), and one Te(5) atom to form GeGeTe3 tetrahedra that share  a cornercorner with one Na(2)Te6 octahedra,  a cornercorner with one Na(3)Te6 octahedra,  a cornercorner with one Te(5)Na4Ge2 octahedra,  a cornercorner with one Te(1)Na5Ge octahedra,  a cornercorner with one Te(4)Na5Ge octahedra, corners with three equivalent Na(1)Te6 octahedra, corners with three equivalent Na(4)Te6 octahedra,  a cornercorner with one Ge(1)GeTe3 tetrahedra,  an edgeedge with one Na(2)Te6 octahedra, and edges with two equivalent Na(3)Te6 octahedra. The corner-sharing octahedral tilt angles range from 16-85°. There are five inequivalent Te sites. In the first Te site, Te(1) is bonded to one Na(1), two equivalent Na(2), two equivalent Na(4), and one Ge(1) atom to form TeNa5Ge octahedra that share  a cornercorner with one Te(2)Na5Ge octahedra,  a cornercorner with one Te(4)Na5Ge octahedra, corners with two equivalent Te(3)Na5Ge octahedra, corners with three equivalent Te(5)Na4Ge2 octahedra,  a cornercorner with one Ge(2)GeTe3 tetrahedra,  an edgeedge with one Te(3)Na5Ge octahedra, edges with two equivalent Te(5)Na4Ge2 octahedra, edges with two equivalent Te(1)Na5Ge octahedra, edges with two equivalent Te(2)Na5Ge octahedra, and edges with three equivalent Te(4)Na5Ge octahedra. The corner-sharing octahedral tilt angles range from 5-86°. In the second Te site, Te(2) is bonded to one Na(1), one Na(2), one Na(4), two equivalent Na(3), and one Ge(2) atom to form TeNa5Ge octahedra that share  a cornercorner with one Te(1)Na5Ge octahedra, corners with two equivalent Te(5)Na4Ge2 octahedra, corners with two equivalent Te(3)Na5Ge octahedra, corners with two equivalent Te(4)Na5Ge octahedra,  a cornercorner with one Ge(1)GeTe3 tetrahedra,  an edgeedge with one Te(2)Na5Ge octahedra, edges with two equivalent Te(5)Na4Ge2 octahedra, edges with two equivalent Te(1)Na5Ge octahedra, edges with two equivalent Te(4)Na5Ge octahedra, and edges with three equivalent Te(3)Na5Ge octahedra. The corner-sharing octahedral tilt angles range from 6-87°. In the third Te site, Te(3) is bonded to one Na(2), two equivalent Na(1), two equivalent Na(3), and one Ge(2) atom to form TeNa5Ge octahedra that share corners with two equivalent Te(1)Na5Ge octahedra, corners with two equivalent Te(2)Na5Ge octahedra, corners with three equivalent Te(4)Na5Ge octahedra,  a cornercorner with one Ge(1)GeTe3 tetrahedra,  an edgeedge with one Te(1)Na5Ge octahedra, edges with two equivalent Te(5)Na4Ge2 octahedra, edges with two equivalent Te(3)Na5Ge octahedra, edges with two equivalent Te(4)Na5Ge octahedra, and edges with three equivalent Te(2)Na5Ge octahedra. The corner-sharing octahedral tilt angles range from 6-86°. In the fourth Te site, Te(4) is bonded to one Na(2), one Na(3), one Na(4), two equivalent Na(1), and one Ge(1) atom to form distorted TeNa5Ge octahedra that share  a cornercorner with one Te(5)Na4Ge2 octahedra,  a cornercorner with one Te(1)Na5Ge octahedra, corners with two equivalent Te(2)Na5Ge octahedra, corners with three equivalent Te(3)Na5Ge octahedra,  a cornercorner with one Ge(2)GeTe3 tetrahedra,  an edgeedge with one Te(4)Na5Ge octahedra, edges with two equivalent Te(5)Na4Ge2 octahedra, edges with two equivalent Te(2)Na5Ge octahedra, edges with two equivalent Te(3)Na5Ge octahedra, and edges with three equivalent Te(1)Na5Ge octahedra. The corner-sharing octahedral tilt angles range from 6-87°. In the fifth Te site, Te(5) is bonded to one Na(2), one Na(3), two equivalent Na(4), one Ge(1), and one Ge(2) atom to form distorted TeNa4Ge2 octahedra that share  a cornercorner with one Te(4)Na5Ge octahedra, corners with two equivalent Te(2)Na5Ge octahedra, corners with three equivalent Te(1)Na5Ge octahedra,  a cornercorner with one Ge(1)GeTe3 tetrahedra,  a cornercorner with one Ge(2)GeTe3 tetrahedra,  an edgeedge with one Te(5)Na4Ge2 octahedra, edges with two equivalent Te(1)Na5Ge octahedra, edges with two equivalent Te(2)Na5Ge octahedra, edges with two equivalent Te(3)Na5Ge octahedra, and edges with two equivalent Te(4)Na5Ge octahedra. The corner-sharing octahedral tilt angles range from 5-85°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na4Ge2Te5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.947
_cell_length_b   9.622
_cell_length_c   10.707
_cell_angle_alpha   68.665
_cell_angle_beta   70.809
_cell_angle_gamma   68.013
_symmetry_Int_Tables_number   1
_cell_volume   689.331
_cell_formula_units_Z   2
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  0.270  0.440  0.427  1.0
  Na  Na1  1  0.730  0.560  0.573  1.0
  Na  Na2  1  0.873  0.368  0.189  1.0
  Na  Na3  1  0.127  0.632  0.811  1.0
  Na  Na4  1  0.679  0.048  0.586  1.0
  Na  Na5  1  0.321  0.952  0.414  1.0
  Na  Na6  1  0.464  0.736  0.019  1.0
  Na  Na7  1  0.536  0.264  0.981  1.0
  Ge  Ge8  1  0.895  0.763  0.145  1.0
  Ge  Ge9  1  0.105  0.237  0.855  1.0
  Ge  Ge10  1  0.915  0.940  0.254  1.0
  Ge  Ge11  1  0.085  0.060  0.746  1.0
  Te  Te12  1  0.810  0.469  0.873  1.0
  Te  Te13  1  0.190  0.531  0.127  1.0
  Te  Te14  1  0.395  0.844  0.719  1.0
  Te  Te15  1  0.605  0.156  0.281  1.0
  Te  Te16  1  0.987  0.231  0.520  1.0
  Te  Te17  1  0.013  0.769  0.480  1.0
  Te  Te18  1  0.395  0.329  0.715  1.0
  Te  Te19  1  0.605  0.671  0.285  1.0
  Te  Te20  1  0.806  0.942  0.906  1.0
  Te  Te21  1  0.194  0.058  0.094  1.0
[/CIF]
.