The structure described by Th8Y2O19 is alpha bismuth trifluoride-derived structured and crystallizes in the monoclinic C2 space group. There are four inequivalent Th sites. In the first Th site, Th(1) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(5), two equivalent O(6), and two equivalent O(7) atoms. In the second Th site, Th(2) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(2), two equivalent O(6), and two equivalent O(9) atoms. In the third Th site, Th(3) is bonded in a body-centered cubic geometry to two equivalent O(10), two equivalent O(2), two equivalent O(3), and two equivalent O(9) atoms. In the fourth Th site, Th(4) is bonded in a body-centered cubic geometry to two equivalent O(10); two equivalent O(3); and four equivalent O(4,11) atoms. Y(1) is bonded in a 6-coordinate geometry to two equivalent O(5), two equivalent O(7), and two equivalent O(8) atoms. There are ten inequivalent O sites. In the first O site, O(9) is bonded to two equivalent Th(2) and two equivalent Th(3) atoms to form a mixture of corner and edge-sharing OTh4 tetrahedra. In the second O site, O(10) is bonded to two equivalent Th(3) and two equivalent Th(4) atoms to form a mixture of corner and edge-sharing OTh4 tetrahedra. In the third O site, O(1) is bonded to two equivalent Th(1) and two equivalent Th(2) atoms to form OTh4 tetrahedra that share corners with two equivalent O(9)Th4 tetrahedra, corners with two equivalent O(7)Y2Th2 tetrahedra, corners with four equivalent O(1)Th4 tetrahedra, corners with four equivalent O(2)Th4 tetrahedra, corners with four equivalent O(5)Y2Th2 tetrahedra,  an edgeedge with one O(9)Th4 tetrahedra,  an edgeedge with one O(7)Y2Th2 tetrahedra, and edges with four equivalent O(6)Th4 tetrahedra. In the fourth O site, O(2) is bonded to two equivalent Th(2) and two equivalent Th(3) atoms to form a mixture of corner and edge-sharing OTh4 tetrahedra. In the fifth O site, O(3) is bonded to two equivalent Th(3) and two equivalent Th(4) atoms to form a mixture of corner and edge-sharing OTh4 tetrahedra. In the sixth O site, O(4,11) is bonded to four equivalent Th(4) atoms to form a mixture of corner and edge-sharing OTh4 tetrahedra. In the seventh O site, O(5) is bonded to two equivalent Th(1) and two equivalent Y(1) atoms to form OY2Th2 tetrahedra that share corners with two equivalent O(6)Th4 tetrahedra, corners with two equivalent O(8)Y4 tetrahedra, corners with four equivalent O(1)Th4 tetrahedra, corners with four equivalent O(5)Y2Th2 tetrahedra,  an edgeedge with one O(6)Th4 tetrahedra,  an edgeedge with one O(8)Y4 tetrahedra, and edges with four equivalent O(7)Y2Th2 tetrahedra. In the eighth O site, O(6) is bonded to two equivalent Th(1) and two equivalent Th(2) atoms to form OTh4 tetrahedra that share corners with two equivalent O(2)Th4 tetrahedra, corners with two equivalent O(5)Y2Th2 tetrahedra, corners with four equivalent O(6)Th4 tetrahedra, corners with four equivalent O(9)Th4 tetrahedra, corners with four equivalent O(7)Y2Th2 tetrahedra,  an edgeedge with one O(2)Th4 tetrahedra,  an edgeedge with one O(5)Y2Th2 tetrahedra, and edges with four equivalent O(1)Th4 tetrahedra. In the ninth O site, O(7) is bonded to two equivalent Th(1) and two equivalent Y(1) atoms to form OY2Th2 tetrahedra that share corners with two equivalent O(1)Th4 tetrahedra, corners with four equivalent O(6)Th4 tetrahedra, corners with four equivalent O(7)Y2Th2 tetrahedra, corners with four equivalent O(8)Y4 tetrahedra,  an edgeedge with one O(1)Th4 tetrahedra, and edges with four equivalent O(5)Y2Th2 tetrahedra. In the tenth O site, O(8) is bonded to four equivalent Y(1) atoms to form OY4 tetrahedra that share corners with four equivalent O(5)Y2Th2 tetrahedra, corners with four equivalent O(8)Y4 tetrahedra, corners with eight equivalent O(7)Y2Th2 tetrahedra, and edges with two equivalent O(5)Y2Th2 tetrahedra. is represented by the CIF file [CIF]
data_Y2Th8O19
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.957
_cell_length_b   3.957
_cell_length_c   27.940
_cell_angle_alpha   89.959
_cell_angle_beta   89.959
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   437.445
_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  Y0  1  0.501  0.991  0.444  1.0
  Y  Y1  1  0.009  0.499  0.556  1.0
  Th  Th2  1  0.503  0.997  0.648  1.0
  Th  Th3  1  1.000  0.497  0.749  1.0
  Th  Th4  1  0.499  0.999  0.850  1.0
  Th  Th5  1  0.999  0.500  0.950  1.0
  Th  Th6  1  0.500  0.001  0.050  1.0
  Th  Th7  1  0.001  0.501  0.150  1.0
  Th  Th8  1  0.503  0.000  0.251  1.0
  Th  Th9  1  0.003  0.497  0.352  1.0
  O  O10  1  0.001  0.997  0.696  1.0
  O  O11  1  0.500  0.498  0.800  1.0
  O  O12  1  0.999  1.000  0.900  1.0
  O  O13  1  0.499  0.501  0.000  1.0
  O  O14  1  0.000  0.001  0.100  1.0
  O  O15  1  0.502  0.500  0.200  1.0
  O  O16  1  0.003  0.999  0.304  1.0
  O  O17  1  0.501  0.495  0.397  1.0
  O  O18  1  0.502  0.500  0.299  1.0
  O  O19  1  0.001  0.995  0.409  1.0
  O  O20  1  0.497  0.503  0.500  1.0
  O  O21  1  0.505  0.499  0.603  1.0
  O  O22  1  0.005  0.999  0.591  1.0
  O  O23  1  0.500  0.498  0.701  1.0
  O  O24  1  1.000  0.997  0.799  1.0
  O  O25  1  0.499  0.499  0.900  1.0
  O  O26  1  0.999  0.001  0.000  1.0
  O  O27  1  0.501  0.501  0.100  1.0
  O  O28  1  0.003  0.000  0.201  1.0
[/CIF]
.
The structure described by Th8Y2O19 is alpha bismuth trifluoride-derived structured and crystallizes in the monoclinic C2 space group. There are four inequivalent Th sites. In the first Th site, Th(1) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(5), two equivalent O(6), and two equivalent O(7) atoms. In the second Th site, Th(2) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(2), two equivalent O(6), and two equivalent O(9) atoms. In the third Th site, Th(3) is bonded in a body-centered cubic geometry to two equivalent O(10), two equivalent O(2), two equivalent O(3), and two equivalent O(9) atoms. In the fourth Th site, Th(4) is bonded in a body-centered cubic geometry to two equivalent O(10); two equivalent O(3); and four equivalent O(4,11) atoms. Y(1) is bonded in a 6-coordinate geometry to two equivalent O(5), two equivalent O(7), and two equivalent O(8) atoms. There are ten inequivalent O sites. In the first O site, O(9) is bonded to two equivalent Th(2) and two equivalent Th(3) atoms to form a mixture of corner and edge-sharing OTh4 tetrahedra. In the second O site, O(10) is bonded to two equivalent Th(3) and two equivalent Th(4) atoms to form a mixture of corner and edge-sharing OTh4 tetrahedra. In the third O site, O(1) is bonded to two equivalent Th(1) and two equivalent Th(2) atoms to form OTh4 tetrahedra that share corners with two equivalent O(9)Th4 tetrahedra, corners with two equivalent O(7)Y2Th2 tetrahedra, corners with four equivalent O(1)Th4 tetrahedra, corners with four equivalent O(2)Th4 tetrahedra, corners with four equivalent O(5)Y2Th2 tetrahedra,  an edgeedge with one O(9)Th4 tetrahedra,  an edgeedge with one O(7)Y2Th2 tetrahedra, and edges with four equivalent O(6)Th4 tetrahedra. In the fourth O site, O(2) is bonded to two equivalent Th(2) and two equivalent Th(3) atoms to form a mixture of corner and edge-sharing OTh4 tetrahedra. In the fifth O site, O(3) is bonded to two equivalent Th(3) and two equivalent Th(4) atoms to form a mixture of corner and edge-sharing OTh4 tetrahedra. In the sixth O site, O(4,11) is bonded to four equivalent Th(4) atoms to form a mixture of corner and edge-sharing OTh4 tetrahedra. In the seventh O site, O(5) is bonded to two equivalent Th(1) and two equivalent Y(1) atoms to form OY2Th2 tetrahedra that share corners with two equivalent O(6)Th4 tetrahedra, corners with two equivalent O(8)Y4 tetrahedra, corners with four equivalent O(1)Th4 tetrahedra, corners with four equivalent O(5)Y2Th2 tetrahedra,  an edgeedge with one O(6)Th4 tetrahedra,  an edgeedge with one O(8)Y4 tetrahedra, and edges with four equivalent O(7)Y2Th2 tetrahedra. In the eighth O site, O(6) is bonded to two equivalent Th(1) and two equivalent Th(2) atoms to form OTh4 tetrahedra that share corners with two equivalent O(2)Th4 tetrahedra, corners with two equivalent O(5)Y2Th2 tetrahedra, corners with four equivalent O(6)Th4 tetrahedra, corners with four equivalent O(9)Th4 tetrahedra, corners with four equivalent O(7)Y2Th2 tetrahedra,  an edgeedge with one O(2)Th4 tetrahedra,  an edgeedge with one O(5)Y2Th2 tetrahedra, and edges with four equivalent O(1)Th4 tetrahedra. In the ninth O site, O(7) is bonded to two equivalent Th(1) and two equivalent Y(1) atoms to form OY2Th2 tetrahedra that share corners with two equivalent O(1)Th4 tetrahedra, corners with four equivalent O(6)Th4 tetrahedra, corners with four equivalent O(7)Y2Th2 tetrahedra, corners with four equivalent O(8)Y4 tetrahedra,  an edgeedge with one O(1)Th4 tetrahedra, and edges with four equivalent O(5)Y2Th2 tetrahedra. In the tenth O site, O(8) is bonded to four equivalent Y(1) atoms to form OY4 tetrahedra that share corners with four equivalent O(5)Y2Th2 tetrahedra, corners with four equivalent O(8)Y4 tetrahedra, corners with eight equivalent O(7)Y2Th2 tetrahedra, and edges with two equivalent O(5)Y2Th2 tetrahedra. is represented by the CIF file [CIF]
data_Y2Th8O19
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.957
_cell_length_b   3.957
_cell_length_c   27.940
_cell_angle_alpha   89.959
_cell_angle_beta   89.959
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   437.445
_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  Y0  1  0.501  0.991  0.444  1.0
  Y  Y1  1  0.009  0.499  0.556  1.0
  Th  Th2  1  0.503  0.997  0.648  1.0
  Th  Th3  1  1.000  0.497  0.749  1.0
  Th  Th4  1  0.499  0.999  0.850  1.0
  Th  Th5  1  0.999  0.500  0.950  1.0
  Th  Th6  1  0.500  0.001  0.050  1.0
  Th  Th7  1  0.001  0.501  0.150  1.0
  Th  Th8  1  0.503  0.000  0.251  1.0
  Th  Th9  1  0.003  0.497  0.352  1.0
  O  O10  1  0.001  0.997  0.696  1.0
  O  O11  1  0.500  0.498  0.800  1.0
  O  O12  1  0.999  1.000  0.900  1.0
  O  O13  1  0.499  0.501  0.000  1.0
  O  O14  1  0.000  0.001  0.100  1.0
  O  O15  1  0.502  0.500  0.200  1.0
  O  O16  1  0.003  0.999  0.304  1.0
  O  O17  1  0.501  0.495  0.397  1.0
  O  O18  1  0.502  0.500  0.299  1.0
  O  O19  1  0.001  0.995  0.409  1.0
  O  O20  1  0.497  0.503  0.500  1.0
  O  O21  1  0.505  0.499  0.603  1.0
  O  O22  1  0.005  0.999  0.591  1.0
  O  O23  1  0.500  0.498  0.701  1.0
  O  O24  1  1.000  0.997  0.799  1.0
  O  O25  1  0.499  0.499  0.900  1.0
  O  O26  1  0.999  0.001  0.000  1.0
  O  O27  1  0.501  0.501  0.100  1.0
  O  O28  1  0.003  0.000  0.201  1.0
[/CIF]
.