The compound described by K3Ta2AsSe11 crystallizes in the monoclinic Cc space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 9-coordinate geometry to one Se(10), one Se(11), one Se(2), one Se(3), one Se(8), two equivalent Se(4), and two equivalent Se(6) atoms. In the second K site, K(2) is bonded in a 7-coordinate geometry to one Se(11), one Se(3), one Se(6), one Se(8), one Se(9), and two equivalent Se(1) atoms. In the third K site, K(3) is bonded in a 7-coordinate geometry to one As(1), one Se(2), one Se(6), one Se(7), one Se(9), and two equivalent Se(4) atoms. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one Se(10), one Se(3), one Se(5), one Se(6), one Se(7), one Se(8), and one Se(9) atom to form distorted face-sharing TaSe7 pentagonal bipyramids. In the second Ta site, Ta(2) is bonded to one Se(1), one Se(10), one Se(11), one Se(2), one Se(3), one Se(4), and one Se(7) atom to form distorted face-sharing TaSe7 pentagonal bipyramids. As(1) is bonded in a 4-coordinate geometry to one K(3), one Se(1), one Se(5), and one Se(9) atom. There are eleven inequivalent Se sites. In the first Se site, Se(8) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Ta(1), and one Se(3) atom. In the second Se site, Se(9) is bonded in a distorted L-shaped geometry to one K(2), one K(3), one Ta(1), and one As(1) atom. In the third Se site, Se(10) is bonded in a 4-coordinate geometry to one K(1), one Ta(1), one Ta(2), and one Se(11) atom. In the fourth Se site, Se(11) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Ta(2), and one Se(10) atom. In the fifth Se site, Se(1) is bonded in a 4-coordinate geometry to two equivalent K(2), one Ta(2), and one As(1) atom. In the sixth Se site, Se(2) is bonded in a 4-coordinate geometry to one K(1), one K(3), one Ta(2), and one Se(7) atom. In the seventh Se site, Se(3) is bonded in a 5-coordinate geometry to one K(1), one K(2), one Ta(1), one Ta(2), and one Se(8) atom. In the eighth Se site, Se(4) is bonded in a 5-coordinate geometry to two equivalent K(1), two equivalent K(3), and one Ta(2) atom. In the ninth Se site, Se(5) is bonded in an L-shaped geometry to one Ta(1) and one As(1) atom. In the tenth Se site, Se(6) is bonded in a distorted single-bond geometry to one K(2), one K(3), two equivalent K(1), and one Ta(1) atom. In the eleventh Se site, Se(7) is bonded in a 2-coordinate geometry to one K(3), one Ta(1), one Ta(2), and one Se(2) atom. is represented by the CIF file [CIF]
data_K3Ta2AsSe11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.106
_cell_length_b   10.106
_cell_length_c   10.100
_cell_angle_alpha   82.586
_cell_angle_beta   82.586
_cell_angle_gamma   82.237
_symmetry_Int_Tables_number   1
_cell_volume   1006.905
_cell_formula_units_Z   2
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  0.666  0.800  0.917  1.0
  K  K1  1  0.433  0.270  0.166  1.0
  K  K2  1  0.800  0.666  0.417  1.0
  K  K3  1  0.901  0.054  0.253  1.0
  K  K4  1  0.270  0.433  0.666  1.0
  K  K5  1  0.054  0.901  0.753  1.0
  Ta  Ta6  1  0.826  0.410  0.831  1.0
  Ta  Ta7  1  0.707  0.160  0.646  1.0
  Ta  Ta8  1  0.410  0.826  0.331  1.0
  Ta  Ta9  1  0.160  0.707  0.146  1.0
  As  As10  1  0.046  0.349  0.098  1.0
  As  As11  1  0.349  0.046  0.598  1.0
  Se  Se12  1  0.201  0.506  0.993  1.0
  Se  Se13  1  0.815  0.313  0.438  1.0
  Se  Se14  1  0.639  0.443  0.668  1.0
  Se  Se15  1  0.941  0.785  0.089  1.0
  Se  Se16  1  0.785  0.941  0.589  1.0
  Se  Se17  1  0.441  0.814  0.588  1.0
  Se  Se18  1  0.598  0.940  0.245  1.0
  Se  Se19  1  0.944  0.259  0.627  1.0
  Se  Se20  1  0.259  0.944  0.127  1.0
  Se  Se21  1  0.313  0.815  0.938  1.0
  Se  Se22  1  0.814  0.441  0.088  1.0
  Se  Se23  1  0.574  0.494  0.893  1.0
  Se  Se24  1  0.226  0.034  0.404  1.0
  Se  Se25  1  0.034  0.226  0.904  1.0
  Se  Se26  1  0.142  0.739  0.403  1.0
  Se  Se27  1  0.133  0.516  0.343  1.0
  Se  Se28  1  0.443  0.639  0.168  1.0
  Se  Se29  1  0.516  0.133  0.843  1.0
  Se  Se30  1  0.506  0.201  0.493  1.0
  Se  Se31  1  0.940  0.598  0.745  1.0
  Se  Se32  1  0.739  0.142  0.903  1.0
  Se  Se33  1  0.494  0.574  0.393  1.0
[/CIF]
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The compound described by K3Ta2AsSe11 crystallizes in the monoclinic Cc space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 9-coordinate geometry to one Se(10), one Se(11), one Se(2), one Se(3), one Se(8), two equivalent Se(4), and two equivalent Se(6) atoms. In the second K site, K(2) is bonded in a 7-coordinate geometry to one Se(11), one Se(3), one Se(6), one Se(8), one Se(9), and two equivalent Se(1) atoms. In the third K site, K(3) is bonded in a 7-coordinate geometry to one As(1), one Se(2), one Se(6), one Se(7), one Se(9), and two equivalent Se(4) atoms. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one Se(10), one Se(3), one Se(5), one Se(6), one Se(7), one Se(8), and one Se(9) atom to form distorted face-sharing TaSe7 pentagonal bipyramids. In the second Ta site, Ta(2) is bonded to one Se(1), one Se(10), one Se(11), one Se(2), one Se(3), one Se(4), and one Se(7) atom to form distorted face-sharing TaSe7 pentagonal bipyramids. As(1) is bonded in a 4-coordinate geometry to one K(3), one Se(1), one Se(5), and one Se(9) atom. There are eleven inequivalent Se sites. In the first Se site, Se(8) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Ta(1), and one Se(3) atom. In the second Se site, Se(9) is bonded in a distorted L-shaped geometry to one K(2), one K(3), one Ta(1), and one As(1) atom. In the third Se site, Se(10) is bonded in a 4-coordinate geometry to one K(1), one Ta(1), one Ta(2), and one Se(11) atom. In the fourth Se site, Se(11) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Ta(2), and one Se(10) atom. In the fifth Se site, Se(1) is bonded in a 4-coordinate geometry to two equivalent K(2), one Ta(2), and one As(1) atom. In the sixth Se site, Se(2) is bonded in a 4-coordinate geometry to one K(1), one K(3), one Ta(2), and one Se(7) atom. In the seventh Se site, Se(3) is bonded in a 5-coordinate geometry to one K(1), one K(2), one Ta(1), one Ta(2), and one Se(8) atom. In the eighth Se site, Se(4) is bonded in a 5-coordinate geometry to two equivalent K(1), two equivalent K(3), and one Ta(2) atom. In the ninth Se site, Se(5) is bonded in an L-shaped geometry to one Ta(1) and one As(1) atom. In the tenth Se site, Se(6) is bonded in a distorted single-bond geometry to one K(2), one K(3), two equivalent K(1), and one Ta(1) atom. In the eleventh Se site, Se(7) is bonded in a 2-coordinate geometry to one K(3), one Ta(1), one Ta(2), and one Se(2) atom. is represented by the CIF file [CIF]
data_K3Ta2AsSe11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.106
_cell_length_b   10.106
_cell_length_c   10.100
_cell_angle_alpha   82.586
_cell_angle_beta   82.586
_cell_angle_gamma   82.237
_symmetry_Int_Tables_number   1
_cell_volume   1006.905
_cell_formula_units_Z   2
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  0.666  0.800  0.917  1.0
  K  K1  1  0.433  0.270  0.166  1.0
  K  K2  1  0.800  0.666  0.417  1.0
  K  K3  1  0.901  0.054  0.253  1.0
  K  K4  1  0.270  0.433  0.666  1.0
  K  K5  1  0.054  0.901  0.753  1.0
  Ta  Ta6  1  0.826  0.410  0.831  1.0
  Ta  Ta7  1  0.707  0.160  0.646  1.0
  Ta  Ta8  1  0.410  0.826  0.331  1.0
  Ta  Ta9  1  0.160  0.707  0.146  1.0
  As  As10  1  0.046  0.349  0.098  1.0
  As  As11  1  0.349  0.046  0.598  1.0
  Se  Se12  1  0.201  0.506  0.993  1.0
  Se  Se13  1  0.815  0.313  0.438  1.0
  Se  Se14  1  0.639  0.443  0.668  1.0
  Se  Se15  1  0.941  0.785  0.089  1.0
  Se  Se16  1  0.785  0.941  0.589  1.0
  Se  Se17  1  0.441  0.814  0.588  1.0
  Se  Se18  1  0.598  0.940  0.245  1.0
  Se  Se19  1  0.944  0.259  0.627  1.0
  Se  Se20  1  0.259  0.944  0.127  1.0
  Se  Se21  1  0.313  0.815  0.938  1.0
  Se  Se22  1  0.814  0.441  0.088  1.0
  Se  Se23  1  0.574  0.494  0.893  1.0
  Se  Se24  1  0.226  0.034  0.404  1.0
  Se  Se25  1  0.034  0.226  0.904  1.0
  Se  Se26  1  0.142  0.739  0.403  1.0
  Se  Se27  1  0.133  0.516  0.343  1.0
  Se  Se28  1  0.443  0.639  0.168  1.0
  Se  Se29  1  0.516  0.133  0.843  1.0
  Se  Se30  1  0.506  0.201  0.493  1.0
  Se  Se31  1  0.940  0.598  0.745  1.0
  Se  Se32  1  0.739  0.142  0.903  1.0
  Se  Se33  1  0.494  0.574  0.393  1.0
[/CIF]
.