The material described by V8Tl2O21 crystallizes in the monoclinic C2/m space group. There are four inequivalent V sites. In the first V site, V(1) is bonded in a 5-coordinate geometry to one O(1), one O(8), and three equivalent O(7) atoms. In the second V site, V(2) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(3), one O(9), and two equivalent O(5) atoms. In the third V site, V(3) is bonded in a 6-coordinate geometry to one O(10), one O(4), one O(5), and three equivalent O(3) atoms. In the fourth V site, V(4) is bonded in a 5-coordinate geometry to one O(10), one O(6), one O(8), and two equivalent O(2) atoms. Tl(1) is bonded in a 4-coordinate geometry to one O(4), one O(6), and two equivalent O(1) atoms. There are eleven inequivalent O sites. In the first O site, O(10) is bonded in a distorted trigonal planar geometry to one V(2), one V(3), and one V(4) atom. In the second O site, O(11) is bonded in a single-bond geometry to one V(2) atom. In the third O site, O(1) is bonded in a single-bond geometry to one V(1) and two equivalent Tl(1) atoms. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to two equivalent V(4) atoms. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one V(2) and three equivalent V(3) atoms. In the sixth O site, O(4) is bonded in a single-bond geometry to one V(3) and one Tl(1) atom. In the seventh O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one V(3) and two equivalent V(2) atoms. In the eighth O site, O(6) is bonded in a single-bond geometry to one V(4) and one Tl(1) atom. In the ninth O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to three equivalent V(1) atoms. In the tenth O site, O(8) is bonded in a bent 120 degrees geometry to one V(1) and one V(4) atom. In the eleventh O site, O(9) is bonded in a linear geometry to two equivalent V(2) atoms. is represented by the CIF file [CIF]
data_Tl2V8O21
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.814
_cell_length_b   7.814
_cell_length_c   14.978
_cell_angle_alpha   89.737
_cell_angle_beta   89.737
_cell_angle_gamma   26.341
_symmetry_Int_Tables_number   1
_cell_volume   405.809
_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
  Tl  Tl0  1  0.473  0.473  0.313  1.0
  Tl  Tl1  1  0.527  0.527  0.687  1.0
  V  V2  1  0.170  0.170  0.476  1.0
  V  V3  1  0.092  0.092  0.074  1.0
  V  V4  1  0.312  0.312  0.072  1.0
  V  V5  1  0.191  0.191  0.268  1.0
  V  V6  1  0.908  0.908  0.926  1.0
  V  V7  1  0.809  0.809  0.732  1.0
  V  V8  1  0.830  0.830  0.524  1.0
  V  V9  1  0.688  0.688  0.928  1.0
  O  O10  1  0.906  0.906  0.449  1.0
  O  O11  1  0.336  0.336  0.742  1.0
  O  O12  1  0.194  0.194  0.967  1.0
  O  O13  1  0.390  0.390  0.143  1.0
  O  O14  1  0.664  0.664  0.258  1.0
  O  O15  1  0.382  0.382  0.952  1.0
  O  O16  1  0.806  0.806  0.033  1.0
  O  O17  1  0.713  0.713  0.687  1.0
  O  O18  1  0.710  0.710  0.470  1.0
  O  O19  1  0.116  0.116  0.373  1.0
  O  O20  1  0.094  0.094  0.551  1.0
  O  O21  1  0.000  0.000  0.000  1.0
  O  O22  1  0.215  0.215  0.140  1.0
  O  O23  1  0.618  0.618  0.048  1.0
  O  O24  1  0.952  0.952  0.827  1.0
  O  O25  1  0.884  0.884  0.627  1.0
  O  O26  1  0.290  0.290  0.530  1.0
  O  O27  1  0.785  0.785  0.860  1.0
  O  O28  1  0.610  0.610  0.857  1.0
  O  O29  1  0.048  0.048  0.173  1.0
  O  O30  1  0.287  0.287  0.313  1.0
[/CIF]
.
The material described by V8Tl2O21 crystallizes in the monoclinic C2/m space group. There are four inequivalent V sites. In the first V site, V(1) is bonded in a 5-coordinate geometry to one O(1), one O(8), and three equivalent O(7) atoms. In the second V site, V(2) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(3), one O(9), and two equivalent O(5) atoms. In the third V site, V(3) is bonded in a 6-coordinate geometry to one O(10), one O(4), one O(5), and three equivalent O(3) atoms. In the fourth V site, V(4) is bonded in a 5-coordinate geometry to one O(10), one O(6), one O(8), and two equivalent O(2) atoms. Tl(1) is bonded in a 4-coordinate geometry to one O(4), one O(6), and two equivalent O(1) atoms. There are eleven inequivalent O sites. In the first O site, O(10) is bonded in a distorted trigonal planar geometry to one V(2), one V(3), and one V(4) atom. In the second O site, O(11) is bonded in a single-bond geometry to one V(2) atom. In the third O site, O(1) is bonded in a single-bond geometry to one V(1) and two equivalent Tl(1) atoms. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to two equivalent V(4) atoms. In the fifth O site, O(3) is bonded in a 4-coordinate geometry to one V(2) and three equivalent V(3) atoms. In the sixth O site, O(4) is bonded in a single-bond geometry to one V(3) and one Tl(1) atom. In the seventh O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one V(3) and two equivalent V(2) atoms. In the eighth O site, O(6) is bonded in a single-bond geometry to one V(4) and one Tl(1) atom. In the ninth O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to three equivalent V(1) atoms. In the tenth O site, O(8) is bonded in a bent 120 degrees geometry to one V(1) and one V(4) atom. In the eleventh O site, O(9) is bonded in a linear geometry to two equivalent V(2) atoms. is represented by the CIF file [CIF]
data_Tl2V8O21
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.814
_cell_length_b   7.814
_cell_length_c   14.978
_cell_angle_alpha   89.737
_cell_angle_beta   89.737
_cell_angle_gamma   26.341
_symmetry_Int_Tables_number   1
_cell_volume   405.809
_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
  Tl  Tl0  1  0.473  0.473  0.313  1.0
  Tl  Tl1  1  0.527  0.527  0.687  1.0
  V  V2  1  0.170  0.170  0.476  1.0
  V  V3  1  0.092  0.092  0.074  1.0
  V  V4  1  0.312  0.312  0.072  1.0
  V  V5  1  0.191  0.191  0.268  1.0
  V  V6  1  0.908  0.908  0.926  1.0
  V  V7  1  0.809  0.809  0.732  1.0
  V  V8  1  0.830  0.830  0.524  1.0
  V  V9  1  0.688  0.688  0.928  1.0
  O  O10  1  0.906  0.906  0.449  1.0
  O  O11  1  0.336  0.336  0.742  1.0
  O  O12  1  0.194  0.194  0.967  1.0
  O  O13  1  0.390  0.390  0.143  1.0
  O  O14  1  0.664  0.664  0.258  1.0
  O  O15  1  0.382  0.382  0.952  1.0
  O  O16  1  0.806  0.806  0.033  1.0
  O  O17  1  0.713  0.713  0.687  1.0
  O  O18  1  0.710  0.710  0.470  1.0
  O  O19  1  0.116  0.116  0.373  1.0
  O  O20  1  0.094  0.094  0.551  1.0
  O  O21  1  0.000  0.000  0.000  1.0
  O  O22  1  0.215  0.215  0.140  1.0
  O  O23  1  0.618  0.618  0.048  1.0
  O  O24  1  0.952  0.952  0.827  1.0
  O  O25  1  0.884  0.884  0.627  1.0
  O  O26  1  0.290  0.290  0.530  1.0
  O  O27  1  0.785  0.785  0.860  1.0
  O  O28  1  0.610  0.610  0.857  1.0
  O  O29  1  0.048  0.048  0.173  1.0
  O  O30  1  0.287  0.287  0.313  1.0
[/CIF]
.