The material described by K4Mo6Se25O crystallizes in the monoclinic Cm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one Se(10), one Se(12), one Se(14), one Se(2), one Se(3), one Se(9), and two equivalent Se(5) atoms. In the second K site, K(2) is bonded in a 6-coordinate geometry to one Se(1), one Se(10), one Se(11), one Se(13), one Se(9), and two equivalent Se(6) atoms. There are four inequivalent Mo sites. In the first Mo site, Mo(1) is bonded in a distorted single-bond geometry to one Se(12), one Se(2), two equivalent Se(16), two equivalent Se(3), and one O(1) atom. In the second Mo site, Mo(2) is bonded in a 7-coordinate geometry to one Se(1), one Se(11), one Se(17), two equivalent Se(15), and two equivalent Se(4) atoms. In the third Mo site, Mo(3) is bonded in a distorted single-bond geometry to one Se(13), one Se(16), one Se(3), one Se(6), one Se(7), one Se(9), and one O(1) atom. In the fourth Mo site, Mo(4) is bonded to one Se(10), one Se(14), one Se(15), one Se(17), one Se(4), one Se(5), and one Se(8) atom to form distorted face-sharing MoSe7 pentagonal bipyramids. There are seventeen inequivalent Se sites. In the first Se site, Se(1) is bonded in a 4-coordinate geometry to two equivalent K(2), one Mo(2), and one Se(11) atom. In the second Se site, Se(2) is bonded in a 4-coordinate geometry to two equivalent K(1), one Mo(1), and one Se(12) atom. In the third Se site, Se(3) is bonded in a 3-coordinate geometry to one K(1), one Mo(1), one Mo(3), and one Se(16) atom. In the fourth Se site, Se(4) is bonded in a 3-coordinate geometry to one Mo(2), one Mo(4), and one Se(15) atom. In the fifth Se site, Se(5) is bonded in a 4-coordinate geometry to two equivalent K(1), one Mo(4), and one Se(10) atom. In the sixth Se site, Se(6) is bonded in a 4-coordinate geometry to two equivalent K(2), one Mo(3), and one Se(9) atom. In the seventh Se site, Se(7) is bonded in a 3-coordinate geometry to two equivalent Mo(3) and one Se(13) atom. In the eighth Se site, Se(8) is bonded in a 3-coordinate geometry to two equivalent Mo(4) and one Se(14) atom. In the ninth Se site, Se(9) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Mo(3), and one Se(6) atom. In the tenth Se site, Se(10) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Mo(4), and one Se(5) atom. In the eleventh Se site, Se(11) is bonded in a 4-coordinate geometry to two equivalent K(2), one Mo(2), and one Se(1) atom. In the twelfth Se site, Se(12) is bonded in a 4-coordinate geometry to two equivalent K(1), one Mo(1), and one Se(2) atom. In the thirteenth Se site, Se(13) is bonded in a 5-coordinate geometry to two equivalent K(2), two equivalent Mo(3), and one Se(7) atom. In the fourteenth Se site, Se(14) is bonded in a 5-coordinate geometry to two equivalent K(1), two equivalent Mo(4), and one Se(8) atom. In the fifteenth Se site, Se(15) is bonded in a 3-coordinate geometry to one Mo(2), one Mo(4), and one Se(4) atom. In the sixteenth Se site, Se(16) is bonded in a 3-coordinate geometry to one Mo(1), one Mo(3), and one Se(3) atom. In the seventeenth Se site, Se(17) is bonded in a 3-coordinate geometry to one Mo(2) and two equivalent Mo(4) atoms. O(1) is bonded in a trigonal non-coplanar geometry to one Mo(1) and two equivalent Mo(3) atoms. is represented by the CIF file [CIF]
data_K4Mo6Se25O
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.834
_cell_length_b   10.834
_cell_length_c   11.968
_cell_angle_alpha   72.870
_cell_angle_beta   72.870
_cell_angle_gamma   108.225
_symmetry_Int_Tables_number   1
_cell_volume   1153.665
_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  0.821  0.479  0.621  1.0
  K  K1  1  0.820  0.483  0.120  1.0
  K  K2  1  0.479  0.821  0.621  1.0
  K  K3  1  0.483  0.820  0.120  1.0
  Mo  Mo4  1  0.975  0.975  0.507  1.0
  Mo  Mo5  1  0.990  0.990  0.006  1.0
  Mo  Mo6  1  0.142  0.333  0.362  1.0
  Mo  Mo7  1  0.150  0.313  0.875  1.0
  Mo  Mo8  1  0.333  0.142  0.362  1.0
  Mo  Mo9  1  0.313  0.150  0.875  1.0
  Se  Se10  1  0.805  0.805  0.968  1.0
  Se  Se11  1  0.792  0.792  0.469  1.0
  Se  Se12  1  0.857  0.160  0.453  1.0
  Se  Se13  1  0.863  0.166  0.972  1.0
  Se  Se14  1  0.160  0.857  0.453  1.0
  Se  Se15  1  0.166  0.863  0.972  1.0
  Se  Se16  1  0.135  0.498  0.688  1.0
  Se  Se17  1  0.132  0.517  0.173  1.0
  Se  Se18  1  0.498  0.135  0.688  1.0
  Se  Se19  1  0.517  0.132  0.173  1.0
  Se  Se20  1  0.340  0.340  0.451  1.0
  Se  Se21  1  0.341  0.341  0.968  1.0
  Se  Se22  1  0.139  0.584  0.346  1.0
  Se  Se23  1  0.140  0.559  0.862  1.0
  Se  Se24  1  0.584  0.139  0.346  1.0
  Se  Se25  1  0.559  0.140  0.862  1.0
  Se  Se26  1  0.757  0.757  0.188  1.0
  Se  Se27  1  0.744  0.744  0.691  1.0
  Se  Se28  1  0.428  0.428  0.223  1.0
  Se  Se29  1  0.434  0.434  0.742  1.0
  Se  Se30  1  0.966  0.161  0.119  1.0
  Se  Se31  1  0.955  0.161  0.606  1.0
  Se  Se32  1  0.161  0.966  0.119  1.0
  Se  Se33  1  0.161  0.955  0.606  1.0
  Se  Se34  1  0.149  0.149  0.761  1.0
  O  O35  1  0.149  0.149  0.344  1.0
[/CIF]
.
The material described by K4Mo6Se25O crystallizes in the monoclinic Cm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one Se(10), one Se(12), one Se(14), one Se(2), one Se(3), one Se(9), and two equivalent Se(5) atoms. In the second K site, K(2) is bonded in a 6-coordinate geometry to one Se(1), one Se(10), one Se(11), one Se(13), one Se(9), and two equivalent Se(6) atoms. There are four inequivalent Mo sites. In the first Mo site, Mo(1) is bonded in a distorted single-bond geometry to one Se(12), one Se(2), two equivalent Se(16), two equivalent Se(3), and one O(1) atom. In the second Mo site, Mo(2) is bonded in a 7-coordinate geometry to one Se(1), one Se(11), one Se(17), two equivalent Se(15), and two equivalent Se(4) atoms. In the third Mo site, Mo(3) is bonded in a distorted single-bond geometry to one Se(13), one Se(16), one Se(3), one Se(6), one Se(7), one Se(9), and one O(1) atom. In the fourth Mo site, Mo(4) is bonded to one Se(10), one Se(14), one Se(15), one Se(17), one Se(4), one Se(5), and one Se(8) atom to form distorted face-sharing MoSe7 pentagonal bipyramids. There are seventeen inequivalent Se sites. In the first Se site, Se(1) is bonded in a 4-coordinate geometry to two equivalent K(2), one Mo(2), and one Se(11) atom. In the second Se site, Se(2) is bonded in a 4-coordinate geometry to two equivalent K(1), one Mo(1), and one Se(12) atom. In the third Se site, Se(3) is bonded in a 3-coordinate geometry to one K(1), one Mo(1), one Mo(3), and one Se(16) atom. In the fourth Se site, Se(4) is bonded in a 3-coordinate geometry to one Mo(2), one Mo(4), and one Se(15) atom. In the fifth Se site, Se(5) is bonded in a 4-coordinate geometry to two equivalent K(1), one Mo(4), and one Se(10) atom. In the sixth Se site, Se(6) is bonded in a 4-coordinate geometry to two equivalent K(2), one Mo(3), and one Se(9) atom. In the seventh Se site, Se(7) is bonded in a 3-coordinate geometry to two equivalent Mo(3) and one Se(13) atom. In the eighth Se site, Se(8) is bonded in a 3-coordinate geometry to two equivalent Mo(4) and one Se(14) atom. In the ninth Se site, Se(9) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Mo(3), and one Se(6) atom. In the tenth Se site, Se(10) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Mo(4), and one Se(5) atom. In the eleventh Se site, Se(11) is bonded in a 4-coordinate geometry to two equivalent K(2), one Mo(2), and one Se(1) atom. In the twelfth Se site, Se(12) is bonded in a 4-coordinate geometry to two equivalent K(1), one Mo(1), and one Se(2) atom. In the thirteenth Se site, Se(13) is bonded in a 5-coordinate geometry to two equivalent K(2), two equivalent Mo(3), and one Se(7) atom. In the fourteenth Se site, Se(14) is bonded in a 5-coordinate geometry to two equivalent K(1), two equivalent Mo(4), and one Se(8) atom. In the fifteenth Se site, Se(15) is bonded in a 3-coordinate geometry to one Mo(2), one Mo(4), and one Se(4) atom. In the sixteenth Se site, Se(16) is bonded in a 3-coordinate geometry to one Mo(1), one Mo(3), and one Se(3) atom. In the seventeenth Se site, Se(17) is bonded in a 3-coordinate geometry to one Mo(2) and two equivalent Mo(4) atoms. O(1) is bonded in a trigonal non-coplanar geometry to one Mo(1) and two equivalent Mo(3) atoms. is represented by the CIF file [CIF]
data_K4Mo6Se25O
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.834
_cell_length_b   10.834
_cell_length_c   11.968
_cell_angle_alpha   72.870
_cell_angle_beta   72.870
_cell_angle_gamma   108.225
_symmetry_Int_Tables_number   1
_cell_volume   1153.665
_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  0.821  0.479  0.621  1.0
  K  K1  1  0.820  0.483  0.120  1.0
  K  K2  1  0.479  0.821  0.621  1.0
  K  K3  1  0.483  0.820  0.120  1.0
  Mo  Mo4  1  0.975  0.975  0.507  1.0
  Mo  Mo5  1  0.990  0.990  0.006  1.0
  Mo  Mo6  1  0.142  0.333  0.362  1.0
  Mo  Mo7  1  0.150  0.313  0.875  1.0
  Mo  Mo8  1  0.333  0.142  0.362  1.0
  Mo  Mo9  1  0.313  0.150  0.875  1.0
  Se  Se10  1  0.805  0.805  0.968  1.0
  Se  Se11  1  0.792  0.792  0.469  1.0
  Se  Se12  1  0.857  0.160  0.453  1.0
  Se  Se13  1  0.863  0.166  0.972  1.0
  Se  Se14  1  0.160  0.857  0.453  1.0
  Se  Se15  1  0.166  0.863  0.972  1.0
  Se  Se16  1  0.135  0.498  0.688  1.0
  Se  Se17  1  0.132  0.517  0.173  1.0
  Se  Se18  1  0.498  0.135  0.688  1.0
  Se  Se19  1  0.517  0.132  0.173  1.0
  Se  Se20  1  0.340  0.340  0.451  1.0
  Se  Se21  1  0.341  0.341  0.968  1.0
  Se  Se22  1  0.139  0.584  0.346  1.0
  Se  Se23  1  0.140  0.559  0.862  1.0
  Se  Se24  1  0.584  0.139  0.346  1.0
  Se  Se25  1  0.559  0.140  0.862  1.0
  Se  Se26  1  0.757  0.757  0.188  1.0
  Se  Se27  1  0.744  0.744  0.691  1.0
  Se  Se28  1  0.428  0.428  0.223  1.0
  Se  Se29  1  0.434  0.434  0.742  1.0
  Se  Se30  1  0.966  0.161  0.119  1.0
  Se  Se31  1  0.955  0.161  0.606  1.0
  Se  Se32  1  0.161  0.966  0.119  1.0
  Se  Se33  1  0.161  0.955  0.606  1.0
  Se  Se34  1  0.149  0.149  0.761  1.0
  O  O35  1  0.149  0.149  0.344  1.0
[/CIF]
.