The material described by K2V8O21 crystallizes in the monoclinic C2/m space group. K(1) is bonded in a 9-coordinate geometry to one O(10), one O(6), one O(7), two equivalent O(4), two equivalent O(5), and two equivalent O(8) atoms. There are four inequivalent V sites. In the first V site, V(1) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(3), and three equivalent O(9) atoms. In the second V site, V(2) is bonded in a 6-coordinate geometry to one O(1), one O(11), one O(4), one O(9), and two equivalent O(3) atoms. In the third V site, V(3) is bonded in a 5-coordinate geometry to one O(5), one O(8), and three equivalent O(2) atoms. In the fourth V site, V(4) is bonded in a 5-coordinate geometry to one O(1), one O(5), one O(6), and two equivalent O(7) atoms. There are eleven inequivalent O sites. In the first O site, O(11) is bonded in a linear geometry to two equivalent V(2) atoms. In the second O site, O(1) is bonded in a distorted trigonal planar geometry to one V(1), one V(2), and one V(4) atom. In the third O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to three equivalent V(3) atoms. In the fourth O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one V(1) and two equivalent V(2) atoms. In the fifth O site, O(4) is bonded in a single-bond geometry to two equivalent K(1) and one V(2) atom. In the sixth O site, O(5) is bonded in a distorted bent 120 degrees geometry to two equivalent K(1), one V(3), and one V(4) atom. In the seventh O site, O(6) is bonded in a single-bond geometry to one K(1) and one V(4) atom. In the eighth O site, O(7) is bonded in a bent 150 degrees geometry to one K(1) and two equivalent V(4) atoms. In the ninth O site, O(8) is bonded in a distorted single-bond geometry to two equivalent K(1) and one V(3) atom. In the tenth O site, O(9) is bonded in a 4-coordinate geometry to one V(2) and three equivalent V(1) atoms. In the eleventh O site, O(10) is bonded in a single-bond geometry to one K(1) and one V(1) atom. is represented by the CIF file [CIF]
data_K2V8O21
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.725
_cell_length_b   7.725
_cell_length_c   14.816
_cell_angle_alpha   88.914
_cell_angle_beta   88.914
_cell_angle_gamma   26.683
_symmetry_Int_Tables_number   1
_cell_volume   396.950
_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
  K  K0  1  0.527  0.527  0.688  1.0
  K  K1  1  0.473  0.473  0.312  1.0
  V  V2  1  0.688  0.688  0.928  1.0
  V  V3  1  0.090  0.090  0.076  1.0
  V  V4  1  0.832  0.832  0.521  1.0
  V  V5  1  0.189  0.189  0.271  1.0
  V  V6  1  0.910  0.910  0.924  1.0
  V  V7  1  0.168  0.168  0.479  1.0
  V  V8  1  0.312  0.312  0.072  1.0
  V  V9  1  0.811  0.811  0.729  1.0
  O  O10  1  0.787  0.787  0.859  1.0
  O  O11  1  0.291  0.291  0.528  1.0
  O  O12  1  0.383  0.383  0.950  1.0
  O  O13  1  0.956  0.956  0.824  1.0
  O  O14  1  0.044  0.044  0.176  1.0
  O  O15  1  0.888  0.888  0.623  1.0
  O  O16  1  0.286  0.286  0.315  1.0
  O  O17  1  0.338  0.338  0.739  1.0
  O  O18  1  0.907  0.907  0.442  1.0
  O  O19  1  0.194  0.194  0.966  1.0
  O  O20  1  0.390  0.390  0.144  1.0
  O  O21  1  0.112  0.112  0.377  1.0
  O  O22  1  0.709  0.709  0.472  1.0
  O  O23  1  0.714  0.714  0.685  1.0
  O  O24  1  0.000  0.000  0.000  1.0
  O  O25  1  0.617  0.617  0.050  1.0
  O  O26  1  0.213  0.213  0.141  1.0
  O  O27  1  0.662  0.662  0.261  1.0
  O  O28  1  0.093  0.093  0.558  1.0
  O  O29  1  0.610  0.610  0.856  1.0
  O  O30  1  0.806  0.806  0.034  1.0
[/CIF]
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The material described by K2V8O21 crystallizes in the monoclinic C2/m space group. K(1) is bonded in a 9-coordinate geometry to one O(10), one O(6), one O(7), two equivalent O(4), two equivalent O(5), and two equivalent O(8) atoms. There are four inequivalent V sites. In the first V site, V(1) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(3), and three equivalent O(9) atoms. In the second V site, V(2) is bonded in a 6-coordinate geometry to one O(1), one O(11), one O(4), one O(9), and two equivalent O(3) atoms. In the third V site, V(3) is bonded in a 5-coordinate geometry to one O(5), one O(8), and three equivalent O(2) atoms. In the fourth V site, V(4) is bonded in a 5-coordinate geometry to one O(1), one O(5), one O(6), and two equivalent O(7) atoms. There are eleven inequivalent O sites. In the first O site, O(11) is bonded in a linear geometry to two equivalent V(2) atoms. In the second O site, O(1) is bonded in a distorted trigonal planar geometry to one V(1), one V(2), and one V(4) atom. In the third O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to three equivalent V(3) atoms. In the fourth O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one V(1) and two equivalent V(2) atoms. In the fifth O site, O(4) is bonded in a single-bond geometry to two equivalent K(1) and one V(2) atom. In the sixth O site, O(5) is bonded in a distorted bent 120 degrees geometry to two equivalent K(1), one V(3), and one V(4) atom. In the seventh O site, O(6) is bonded in a single-bond geometry to one K(1) and one V(4) atom. In the eighth O site, O(7) is bonded in a bent 150 degrees geometry to one K(1) and two equivalent V(4) atoms. In the ninth O site, O(8) is bonded in a distorted single-bond geometry to two equivalent K(1) and one V(3) atom. In the tenth O site, O(9) is bonded in a 4-coordinate geometry to one V(2) and three equivalent V(1) atoms. In the eleventh O site, O(10) is bonded in a single-bond geometry to one K(1) and one V(1) atom. is represented by the CIF file [CIF]
data_K2V8O21
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.725
_cell_length_b   7.725
_cell_length_c   14.816
_cell_angle_alpha   88.914
_cell_angle_beta   88.914
_cell_angle_gamma   26.683
_symmetry_Int_Tables_number   1
_cell_volume   396.950
_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
  K  K0  1  0.527  0.527  0.688  1.0
  K  K1  1  0.473  0.473  0.312  1.0
  V  V2  1  0.688  0.688  0.928  1.0
  V  V3  1  0.090  0.090  0.076  1.0
  V  V4  1  0.832  0.832  0.521  1.0
  V  V5  1  0.189  0.189  0.271  1.0
  V  V6  1  0.910  0.910  0.924  1.0
  V  V7  1  0.168  0.168  0.479  1.0
  V  V8  1  0.312  0.312  0.072  1.0
  V  V9  1  0.811  0.811  0.729  1.0
  O  O10  1  0.787  0.787  0.859  1.0
  O  O11  1  0.291  0.291  0.528  1.0
  O  O12  1  0.383  0.383  0.950  1.0
  O  O13  1  0.956  0.956  0.824  1.0
  O  O14  1  0.044  0.044  0.176  1.0
  O  O15  1  0.888  0.888  0.623  1.0
  O  O16  1  0.286  0.286  0.315  1.0
  O  O17  1  0.338  0.338  0.739  1.0
  O  O18  1  0.907  0.907  0.442  1.0
  O  O19  1  0.194  0.194  0.966  1.0
  O  O20  1  0.390  0.390  0.144  1.0
  O  O21  1  0.112  0.112  0.377  1.0
  O  O22  1  0.709  0.709  0.472  1.0
  O  O23  1  0.714  0.714  0.685  1.0
  O  O24  1  0.000  0.000  0.000  1.0
  O  O25  1  0.617  0.617  0.050  1.0
  O  O26  1  0.213  0.213  0.141  1.0
  O  O27  1  0.662  0.662  0.261  1.0
  O  O28  1  0.093  0.093  0.558  1.0
  O  O29  1  0.610  0.610  0.856  1.0
  O  O30  1  0.806  0.806  0.034  1.0
[/CIF]
.