The structure described by U12Ge3Te20 crystallizes in the orthorhombic Pmm2 space group. There are seven inequivalent U sites. In the first U site, U(1) is bonded in a 9-coordinate geometry to two equivalent Ge(2), one Te(1), one Te(2), one Te(9), two equivalent Te(7), and two equivalent Te(8) atoms. In the second U site, U(2) is bonded to one Te(10), two equivalent Te(3), and four equivalent Te(5) atoms to form distorted edge-sharing UTe7 pentagonal bipyramids. In the third U site, U(3) is bonded in a 9-coordinate geometry to two equivalent Ge(1), one Te(11), two equivalent Te(4), and four equivalent Te(6) atoms. In the fourth U site, U(4) is bonded in a 8-coordinate geometry to one Te(1), one Te(5), two equivalent Te(10), two equivalent Te(3), and two equivalent Te(8) atoms. In the fifth U site, U(5) is bonded in a 9-coordinate geometry to one Ge(1), one Te(2), one Te(6), two equivalent Te(11), two equivalent Te(4), and two equivalent Te(7) atoms. In the sixth U site, U(6) is bonded in a 9-coordinate geometry to one Ge(2), one Te(4), one Te(7), two equivalent Te(2), two equivalent Te(6), and two equivalent Te(9) atoms. In the seventh U site, U(7) is bonded in a 9-coordinate geometry to one Ge(2), one Te(3), one Te(8), two equivalent Te(1), two equivalent Te(5), and two equivalent Te(9) atoms. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to two equivalent U(3), two equivalent U(5), and four equivalent Te(4) atoms to form distorted GeU4Te4 hexagonal bipyramids that share corners with two equivalent Te(11)U5 trigonal bipyramids, corners with four equivalent Te(7)U5 trigonal bipyramids, corners with six equivalent Te(6)U5 trigonal bipyramids, edges with two equivalent Te(11)U5 trigonal bipyramids, edges with two equivalent Te(6)U5 trigonal bipyramids, and faces with two equivalent Ge(1)U4Te4 hexagonal bipyramids. In the second Ge site, Ge(2) is bonded to one U(6), one U(7), two equivalent U(1), two equivalent Te(1), and two equivalent Te(2) atoms to form distorted GeU4Te4 hexagonal bipyramids that share corners with two equivalent Te(5)U5 trigonal bipyramids, corners with two equivalent Te(6)U5 trigonal bipyramids, corners with two equivalent Te(9)U5 trigonal bipyramids, corners with three equivalent Te(7)U5 trigonal bipyramids, corners with three equivalent Te(8)U5 trigonal bipyramids,  an edgeedge with one Te(7)U5 trigonal bipyramid,  an edgeedge with one Te(8)U5 trigonal bipyramid, edges with two equivalent Te(9)U5 trigonal bipyramids, and faces with two equivalent Ge(2)U4Te4 hexagonal bipyramids. There are eleven inequivalent Te sites. In the first Te site, Te(1) is bonded in a 6-coordinate geometry to one U(1), one U(4), two equivalent U(7), and two equivalent Ge(2) atoms. In the second Te site, Te(2) is bonded in a 6-coordinate geometry to one U(1), one U(5), two equivalent U(6), and two equivalent Ge(2) atoms. In the third Te site, Te(3) is bonded in a 4-coordinate geometry to one U(2), one U(7), and two equivalent U(4) atoms. In the fourth Te site, Te(4) is bonded in a 6-coordinate geometry to one U(3), one U(6), two equivalent U(5), and two equivalent Ge(1) atoms. In the fifth Te site, Te(5) is bonded to one U(4), two equivalent U(2), and two equivalent U(7) atoms to form distorted TeU5 trigonal bipyramids that share corners with two equivalent Ge(2)U4Te4 hexagonal bipyramids, corners with two equivalent Te(5)U5 trigonal bipyramids, corners with two equivalent Te(9)U5 trigonal bipyramids,  an edgeedge with one Te(9)U5 trigonal bipyramid, edges with two equivalent Te(10)U5 trigonal bipyramids, edges with two equivalent Te(8)U5 trigonal bipyramids, and edges with three equivalent Te(5)U5 trigonal bipyramids. In the sixth Te site, Te(6) is bonded to one U(5), two equivalent U(3), and two equivalent U(6) atoms to form distorted TeU5 trigonal bipyramids that share corners with two equivalent Ge(2)U4Te4 hexagonal bipyramids, corners with three equivalent Ge(1)U4Te4 hexagonal bipyramids, corners with two equivalent Te(6)U5 trigonal bipyramids, corners with two equivalent Te(9)U5 trigonal bipyramids,  an edgeedge with one Ge(1)U4Te4 hexagonal bipyramid,  an edgeedge with one Te(9)U5 trigonal bipyramid, edges with two equivalent Te(11)U5 trigonal bipyramids, edges with two equivalent Te(7)U5 trigonal bipyramids, and edges with three equivalent Te(6)U5 trigonal bipyramids. In the seventh Te site, Te(7) is bonded to one U(6), two equivalent U(1), and two equivalent U(5) atoms to form distorted TeU5 trigonal bipyramids that share corners with two equivalent Ge(1)U4Te4 hexagonal bipyramids, corners with three equivalent Ge(2)U4Te4 hexagonal bipyramids, corners with two equivalent Te(11)U5 trigonal bipyramids, corners with two equivalent Te(8)U5 trigonal bipyramids,  an edgeedge with one Ge(2)U4Te4 hexagonal bipyramid,  an edgeedge with one Te(11)U5 trigonal bipyramid,  an edgeedge with one Te(8)U5 trigonal bipyramid, edges with two equivalent Te(6)U5 trigonal bipyramids, edges with two equivalent Te(7)U5 trigonal bipyramids, and edges with two equivalent Te(9)U5 trigonal bipyramids. In the eighth Te site, Te(8) is bonded to one U(7), two equivalent U(1), and two equivalent U(4) atoms to form distorted TeU5 trigonal bipyramids that share corners with three equivalent Ge(2)U4Te4 hexagonal bipyramids, corners with two equivalent Te(10)U5 trigonal bipyramids, corners with two equivalent Te(7)U5 trigonal bipyramids,  an edgeedge with one Ge(2)U4Te4 hexagonal bipyramid,  an edgeedge with one Te(10)U5 trigonal bipyramid,  an edgeedge with one Te(7)U5 trigonal bipyramid, edges with two equivalent Te(5)U5 trigonal bipyramids, edges with two equivalent Te(8)U5 trigonal bipyramids, and edges with two equivalent Te(9)U5 trigonal bipyramids. In the ninth Te site, Te(9) is bonded to one U(1), two equivalent U(6), and two equivalent U(7) atoms to form distorted TeU5 trigonal bipyramids that share corners with two equivalent Ge(2)U4Te4 hexagonal bipyramids, corners with two equivalent Te(5)U5 trigonal bipyramids, corners with two equivalent Te(6)U5 trigonal bipyramids, edges with two equivalent Ge(2)U4Te4 hexagonal bipyramids,  an edgeedge with one Te(5)U5 trigonal bipyramid,  an edgeedge with one Te(6)U5 trigonal bipyramid, edges with two equivalent Te(7)U5 trigonal bipyramids, edges with two equivalent Te(8)U5 trigonal bipyramids, and edges with two equivalent Te(9)U5 trigonal bipyramids. In the tenth Te site, Te(10) is bonded to one U(2) and four equivalent U(4) atoms to form a mixture of distorted edge and corner-sharing TeU5 trigonal bipyramids. In the eleventh Te site, Te(11) is bonded to one U(3) and four equivalent U(5) atoms to form distorted TeU5 trigonal bipyramids that share corners with two equivalent Ge(1)U4Te4 hexagonal bipyramids, corners with four equivalent Te(7)U5 trigonal bipyramids, edges with two equivalent Ge(1)U4Te4 hexagonal bipyramids, edges with two equivalent Te(11)U5 trigonal bipyramids, edges with two equivalent Te(7)U5 trigonal bipyramids, and edges with four equivalent Te(6)U5 trigonal bipyramids. is represented by the CIF file [CIF]
data_U12Ge3Te20
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.257
_cell_length_b   8.930
_cell_length_c   26.281
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   999.016
_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
  U  U0  1  0.250  0.277  0.125  1.0
  U  U1  1  0.250  0.277  0.625  1.0
  U  U2  1  0.750  0.722  0.375  1.0
  U  U3  1  0.750  0.723  0.875  1.0
  U  U4  1  0.250  0.256  0.460  1.0
  U  U5  1  0.250  0.259  0.958  1.0
  U  U6  1  0.250  0.256  0.290  1.0
  U  U7  1  0.250  0.259  0.792  1.0
  U  U8  1  0.750  0.741  0.043  1.0
  U  U9  1  0.750  0.744  0.542  1.0
  U  U10  1  0.750  0.744  0.208  1.0
  U  U11  1  0.750  0.741  0.707  1.0
  Ge  Ge12  1  0.250  0.993  0.875  1.0
  Ge  Ge13  1  0.750  0.008  0.125  1.0
  Ge  Ge14  1  0.750  0.008  0.625  1.0
  Te  Te15  1  0.250  0.006  0.201  1.0
  Te  Te16  1  0.250  0.007  0.701  1.0
  Te  Te17  1  0.250  0.007  0.049  1.0
  Te  Te18  1  0.250  0.006  0.549  1.0
  Te  Te19  1  0.750  0.994  0.304  1.0
  Te  Te20  1  0.750  0.993  0.799  1.0
  Te  Te21  1  0.750  0.994  0.446  1.0
  Te  Te22  1  0.750  0.993  0.951  1.0
  Te  Te23  1  0.250  0.629  0.459  1.0
  Te  Te24  1  0.250  0.629  0.959  1.0
  Te  Te25  1  0.250  0.629  0.291  1.0
  Te  Te26  1  0.250  0.629  0.791  1.0
  Te  Te27  1  0.750  0.371  0.041  1.0
  Te  Te28  1  0.750  0.372  0.541  1.0
  Te  Te29  1  0.750  0.372  0.209  1.0
  Te  Te30  1  0.750  0.371  0.709  1.0
  Te  Te31  1  0.250  0.640  0.125  1.0
  Te  Te32  1  0.250  0.640  0.625  1.0
  Te  Te33  1  0.750  0.356  0.375  1.0
  Te  Te34  1  0.750  0.360  0.875  1.0
[/CIF]
.
The structure described by U12Ge3Te20 crystallizes in the orthorhombic Pmm2 space group. There are seven inequivalent U sites. In the first U site, U(1) is bonded in a 9-coordinate geometry to two equivalent Ge(2), one Te(1), one Te(2), one Te(9), two equivalent Te(7), and two equivalent Te(8) atoms. In the second U site, U(2) is bonded to one Te(10), two equivalent Te(3), and four equivalent Te(5) atoms to form distorted edge-sharing UTe7 pentagonal bipyramids. In the third U site, U(3) is bonded in a 9-coordinate geometry to two equivalent Ge(1), one Te(11), two equivalent Te(4), and four equivalent Te(6) atoms. In the fourth U site, U(4) is bonded in a 8-coordinate geometry to one Te(1), one Te(5), two equivalent Te(10), two equivalent Te(3), and two equivalent Te(8) atoms. In the fifth U site, U(5) is bonded in a 9-coordinate geometry to one Ge(1), one Te(2), one Te(6), two equivalent Te(11), two equivalent Te(4), and two equivalent Te(7) atoms. In the sixth U site, U(6) is bonded in a 9-coordinate geometry to one Ge(2), one Te(4), one Te(7), two equivalent Te(2), two equivalent Te(6), and two equivalent Te(9) atoms. In the seventh U site, U(7) is bonded in a 9-coordinate geometry to one Ge(2), one Te(3), one Te(8), two equivalent Te(1), two equivalent Te(5), and two equivalent Te(9) atoms. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to two equivalent U(3), two equivalent U(5), and four equivalent Te(4) atoms to form distorted GeU4Te4 hexagonal bipyramids that share corners with two equivalent Te(11)U5 trigonal bipyramids, corners with four equivalent Te(7)U5 trigonal bipyramids, corners with six equivalent Te(6)U5 trigonal bipyramids, edges with two equivalent Te(11)U5 trigonal bipyramids, edges with two equivalent Te(6)U5 trigonal bipyramids, and faces with two equivalent Ge(1)U4Te4 hexagonal bipyramids. In the second Ge site, Ge(2) is bonded to one U(6), one U(7), two equivalent U(1), two equivalent Te(1), and two equivalent Te(2) atoms to form distorted GeU4Te4 hexagonal bipyramids that share corners with two equivalent Te(5)U5 trigonal bipyramids, corners with two equivalent Te(6)U5 trigonal bipyramids, corners with two equivalent Te(9)U5 trigonal bipyramids, corners with three equivalent Te(7)U5 trigonal bipyramids, corners with three equivalent Te(8)U5 trigonal bipyramids,  an edgeedge with one Te(7)U5 trigonal bipyramid,  an edgeedge with one Te(8)U5 trigonal bipyramid, edges with two equivalent Te(9)U5 trigonal bipyramids, and faces with two equivalent Ge(2)U4Te4 hexagonal bipyramids. There are eleven inequivalent Te sites. In the first Te site, Te(1) is bonded in a 6-coordinate geometry to one U(1), one U(4), two equivalent U(7), and two equivalent Ge(2) atoms. In the second Te site, Te(2) is bonded in a 6-coordinate geometry to one U(1), one U(5), two equivalent U(6), and two equivalent Ge(2) atoms. In the third Te site, Te(3) is bonded in a 4-coordinate geometry to one U(2), one U(7), and two equivalent U(4) atoms. In the fourth Te site, Te(4) is bonded in a 6-coordinate geometry to one U(3), one U(6), two equivalent U(5), and two equivalent Ge(1) atoms. In the fifth Te site, Te(5) is bonded to one U(4), two equivalent U(2), and two equivalent U(7) atoms to form distorted TeU5 trigonal bipyramids that share corners with two equivalent Ge(2)U4Te4 hexagonal bipyramids, corners with two equivalent Te(5)U5 trigonal bipyramids, corners with two equivalent Te(9)U5 trigonal bipyramids,  an edgeedge with one Te(9)U5 trigonal bipyramid, edges with two equivalent Te(10)U5 trigonal bipyramids, edges with two equivalent Te(8)U5 trigonal bipyramids, and edges with three equivalent Te(5)U5 trigonal bipyramids. In the sixth Te site, Te(6) is bonded to one U(5), two equivalent U(3), and two equivalent U(6) atoms to form distorted TeU5 trigonal bipyramids that share corners with two equivalent Ge(2)U4Te4 hexagonal bipyramids, corners with three equivalent Ge(1)U4Te4 hexagonal bipyramids, corners with two equivalent Te(6)U5 trigonal bipyramids, corners with two equivalent Te(9)U5 trigonal bipyramids,  an edgeedge with one Ge(1)U4Te4 hexagonal bipyramid,  an edgeedge with one Te(9)U5 trigonal bipyramid, edges with two equivalent Te(11)U5 trigonal bipyramids, edges with two equivalent Te(7)U5 trigonal bipyramids, and edges with three equivalent Te(6)U5 trigonal bipyramids. In the seventh Te site, Te(7) is bonded to one U(6), two equivalent U(1), and two equivalent U(5) atoms to form distorted TeU5 trigonal bipyramids that share corners with two equivalent Ge(1)U4Te4 hexagonal bipyramids, corners with three equivalent Ge(2)U4Te4 hexagonal bipyramids, corners with two equivalent Te(11)U5 trigonal bipyramids, corners with two equivalent Te(8)U5 trigonal bipyramids,  an edgeedge with one Ge(2)U4Te4 hexagonal bipyramid,  an edgeedge with one Te(11)U5 trigonal bipyramid,  an edgeedge with one Te(8)U5 trigonal bipyramid, edges with two equivalent Te(6)U5 trigonal bipyramids, edges with two equivalent Te(7)U5 trigonal bipyramids, and edges with two equivalent Te(9)U5 trigonal bipyramids. In the eighth Te site, Te(8) is bonded to one U(7), two equivalent U(1), and two equivalent U(4) atoms to form distorted TeU5 trigonal bipyramids that share corners with three equivalent Ge(2)U4Te4 hexagonal bipyramids, corners with two equivalent Te(10)U5 trigonal bipyramids, corners with two equivalent Te(7)U5 trigonal bipyramids,  an edgeedge with one Ge(2)U4Te4 hexagonal bipyramid,  an edgeedge with one Te(10)U5 trigonal bipyramid,  an edgeedge with one Te(7)U5 trigonal bipyramid, edges with two equivalent Te(5)U5 trigonal bipyramids, edges with two equivalent Te(8)U5 trigonal bipyramids, and edges with two equivalent Te(9)U5 trigonal bipyramids. In the ninth Te site, Te(9) is bonded to one U(1), two equivalent U(6), and two equivalent U(7) atoms to form distorted TeU5 trigonal bipyramids that share corners with two equivalent Ge(2)U4Te4 hexagonal bipyramids, corners with two equivalent Te(5)U5 trigonal bipyramids, corners with two equivalent Te(6)U5 trigonal bipyramids, edges with two equivalent Ge(2)U4Te4 hexagonal bipyramids,  an edgeedge with one Te(5)U5 trigonal bipyramid,  an edgeedge with one Te(6)U5 trigonal bipyramid, edges with two equivalent Te(7)U5 trigonal bipyramids, edges with two equivalent Te(8)U5 trigonal bipyramids, and edges with two equivalent Te(9)U5 trigonal bipyramids. In the tenth Te site, Te(10) is bonded to one U(2) and four equivalent U(4) atoms to form a mixture of distorted edge and corner-sharing TeU5 trigonal bipyramids. In the eleventh Te site, Te(11) is bonded to one U(3) and four equivalent U(5) atoms to form distorted TeU5 trigonal bipyramids that share corners with two equivalent Ge(1)U4Te4 hexagonal bipyramids, corners with four equivalent Te(7)U5 trigonal bipyramids, edges with two equivalent Ge(1)U4Te4 hexagonal bipyramids, edges with two equivalent Te(11)U5 trigonal bipyramids, edges with two equivalent Te(7)U5 trigonal bipyramids, and edges with four equivalent Te(6)U5 trigonal bipyramids. is represented by the CIF file [CIF]
data_U12Ge3Te20
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.257
_cell_length_b   8.930
_cell_length_c   26.281
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   999.016
_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
  U  U0  1  0.250  0.277  0.125  1.0
  U  U1  1  0.250  0.277  0.625  1.0
  U  U2  1  0.750  0.722  0.375  1.0
  U  U3  1  0.750  0.723  0.875  1.0
  U  U4  1  0.250  0.256  0.460  1.0
  U  U5  1  0.250  0.259  0.958  1.0
  U  U6  1  0.250  0.256  0.290  1.0
  U  U7  1  0.250  0.259  0.792  1.0
  U  U8  1  0.750  0.741  0.043  1.0
  U  U9  1  0.750  0.744  0.542  1.0
  U  U10  1  0.750  0.744  0.208  1.0
  U  U11  1  0.750  0.741  0.707  1.0
  Ge  Ge12  1  0.250  0.993  0.875  1.0
  Ge  Ge13  1  0.750  0.008  0.125  1.0
  Ge  Ge14  1  0.750  0.008  0.625  1.0
  Te  Te15  1  0.250  0.006  0.201  1.0
  Te  Te16  1  0.250  0.007  0.701  1.0
  Te  Te17  1  0.250  0.007  0.049  1.0
  Te  Te18  1  0.250  0.006  0.549  1.0
  Te  Te19  1  0.750  0.994  0.304  1.0
  Te  Te20  1  0.750  0.993  0.799  1.0
  Te  Te21  1  0.750  0.994  0.446  1.0
  Te  Te22  1  0.750  0.993  0.951  1.0
  Te  Te23  1  0.250  0.629  0.459  1.0
  Te  Te24  1  0.250  0.629  0.959  1.0
  Te  Te25  1  0.250  0.629  0.291  1.0
  Te  Te26  1  0.250  0.629  0.791  1.0
  Te  Te27  1  0.750  0.371  0.041  1.0
  Te  Te28  1  0.750  0.372  0.541  1.0
  Te  Te29  1  0.750  0.372  0.209  1.0
  Te  Te30  1  0.750  0.371  0.709  1.0
  Te  Te31  1  0.250  0.640  0.125  1.0
  Te  Te32  1  0.250  0.640  0.625  1.0
  Te  Te33  1  0.750  0.356  0.375  1.0
  Te  Te34  1  0.750  0.360  0.875  1.0
[/CIF]
.