The material described by Ta11Co2Se8 crystallizes in the orthorhombic Pnnm space group. There are six inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 5-coordinate geometry to two equivalent Co(1), one Se(3), and two equivalent Se(1) atoms. In the second Ta site, Ta(2) is bonded in a 4-coordinate geometry to one Co(1), two equivalent Se(2), and two equivalent Se(4) atoms. In the third Ta site, Ta(3) is bonded in a 5-coordinate geometry to two equivalent Co(1), one Se(4), and two equivalent Se(1) atoms. In the fourth Ta site, Ta(4) is bonded in a 5-coordinate geometry to one Co(1), one Se(2), one Se(4), and two equivalent Se(3) atoms. In the fifth Ta site, Ta(5) is bonded in a 5-coordinate geometry to two equivalent Co(1), one Se(2), and two equivalent Se(4) atoms. In the sixth Ta site, Ta(6) is bonded in a distorted square co-planar geometry to two equivalent Co(1) and two equivalent Se(1) atoms. Co(1) is bonded in a 9-coordinate geometry to one Ta(2), one Ta(4), one Ta(6), two equivalent Ta(1), two equivalent Ta(3), and two equivalent Ta(5) atoms. There are four inequivalent Se sites. In the first Se site, Se(3) is bonded in a 3-coordinate geometry to one Ta(1) and two equivalent Ta(4) atoms. In the second Se site, Se(4) is bonded to one Ta(3), one Ta(4), two equivalent Ta(2), and two equivalent Ta(5) atoms to form distorted edge-sharing SeTa6 pentagonal pyramids. In the third Se site, Se(1) is bonded in a 5-coordinate geometry to one Ta(6), two equivalent Ta(1), and two equivalent Ta(3) atoms. In the fourth Se site, Se(2) is bonded in a 4-coordinate geometry to one Ta(4), one Ta(5), and two equivalent Ta(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ta11(CoSe4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.438
_cell_length_b   12.195
_cell_length_c   19.641
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   823.412
_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
  Ta  Ta0  1  0.500  0.820  0.053  1.0
  Ta  Ta1  1  0.500  0.180  0.947  1.0
  Ta  Ta2  1  0.000  0.680  0.553  1.0
  Ta  Ta3  1  0.000  0.320  0.447  1.0
  Ta  Ta4  1  0.500  0.446  0.742  1.0
  Ta  Ta5  1  0.500  0.554  0.258  1.0
  Ta  Ta6  1  0.000  0.946  0.758  1.0
  Ta  Ta7  1  0.000  0.054  0.242  1.0
  Ta  Ta8  1  0.500  0.061  0.116  1.0
  Ta  Ta9  1  0.500  0.939  0.884  1.0
  Ta  Ta10  1  0.000  0.561  0.384  1.0
  Ta  Ta11  1  0.000  0.439  0.616  1.0
  Ta  Ta12  1  0.500  0.174  0.353  1.0
  Ta  Ta13  1  0.500  0.826  0.647  1.0
  Ta  Ta14  1  0.000  0.674  0.147  1.0
  Ta  Ta15  1  0.000  0.326  0.853  1.0
  Ta  Ta16  1  0.500  0.153  0.788  1.0
  Ta  Ta17  1  0.500  0.847  0.212  1.0
  Ta  Ta18  1  0.000  0.653  0.712  1.0
  Ta  Ta19  1  0.000  0.347  0.288  1.0
  Ta  Ta20  1  0.500  0.500  0.500  1.0
  Ta  Ta21  1  0.000  0.000  0.000  1.0
  Co  Co22  1  0.000  0.093  0.872  1.0
  Co  Co23  1  0.000  0.907  0.128  1.0
  Co  Co24  1  0.500  0.593  0.628  1.0
  Co  Co25  1  0.500  0.407  0.372  1.0
  Se  Se26  1  0.500  0.296  0.555  1.0
  Se  Se27  1  0.500  0.704  0.445  1.0
  Se  Se28  1  0.000  0.796  0.945  1.0
  Se  Se29  1  0.000  0.204  0.055  1.0
  Se  Se30  1  0.500  0.040  0.674  1.0
  Se  Se31  1  0.500  0.960  0.326  1.0
  Se  Se32  1  0.000  0.540  0.826  1.0
  Se  Se33  1  0.000  0.460  0.174  1.0
  Se  Se34  1  0.500  0.390  0.946  1.0
  Se  Se35  1  0.500  0.610  0.054  1.0
  Se  Se36  1  0.000  0.890  0.554  1.0
  Se  Se37  1  0.000  0.110  0.446  1.0
  Se  Se38  1  0.000  0.284  0.714  1.0
  Se  Se39  1  0.000  0.716  0.286  1.0
  Se  Se40  1  0.500  0.784  0.786  1.0
  Se  Se41  1  0.500  0.216  0.214  1.0
[/CIF]
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The material described by Ta11Co2Se8 crystallizes in the orthorhombic Pnnm space group. There are six inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 5-coordinate geometry to two equivalent Co(1), one Se(3), and two equivalent Se(1) atoms. In the second Ta site, Ta(2) is bonded in a 4-coordinate geometry to one Co(1), two equivalent Se(2), and two equivalent Se(4) atoms. In the third Ta site, Ta(3) is bonded in a 5-coordinate geometry to two equivalent Co(1), one Se(4), and two equivalent Se(1) atoms. In the fourth Ta site, Ta(4) is bonded in a 5-coordinate geometry to one Co(1), one Se(2), one Se(4), and two equivalent Se(3) atoms. In the fifth Ta site, Ta(5) is bonded in a 5-coordinate geometry to two equivalent Co(1), one Se(2), and two equivalent Se(4) atoms. In the sixth Ta site, Ta(6) is bonded in a distorted square co-planar geometry to two equivalent Co(1) and two equivalent Se(1) atoms. Co(1) is bonded in a 9-coordinate geometry to one Ta(2), one Ta(4), one Ta(6), two equivalent Ta(1), two equivalent Ta(3), and two equivalent Ta(5) atoms. There are four inequivalent Se sites. In the first Se site, Se(3) is bonded in a 3-coordinate geometry to one Ta(1) and two equivalent Ta(4) atoms. In the second Se site, Se(4) is bonded to one Ta(3), one Ta(4), two equivalent Ta(2), and two equivalent Ta(5) atoms to form distorted edge-sharing SeTa6 pentagonal pyramids. In the third Se site, Se(1) is bonded in a 5-coordinate geometry to one Ta(6), two equivalent Ta(1), and two equivalent Ta(3) atoms. In the fourth Se site, Se(2) is bonded in a 4-coordinate geometry to one Ta(4), one Ta(5), and two equivalent Ta(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ta11(CoSe4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.438
_cell_length_b   12.195
_cell_length_c   19.641
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   823.412
_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
  Ta  Ta0  1  0.500  0.820  0.053  1.0
  Ta  Ta1  1  0.500  0.180  0.947  1.0
  Ta  Ta2  1  0.000  0.680  0.553  1.0
  Ta  Ta3  1  0.000  0.320  0.447  1.0
  Ta  Ta4  1  0.500  0.446  0.742  1.0
  Ta  Ta5  1  0.500  0.554  0.258  1.0
  Ta  Ta6  1  0.000  0.946  0.758  1.0
  Ta  Ta7  1  0.000  0.054  0.242  1.0
  Ta  Ta8  1  0.500  0.061  0.116  1.0
  Ta  Ta9  1  0.500  0.939  0.884  1.0
  Ta  Ta10  1  0.000  0.561  0.384  1.0
  Ta  Ta11  1  0.000  0.439  0.616  1.0
  Ta  Ta12  1  0.500  0.174  0.353  1.0
  Ta  Ta13  1  0.500  0.826  0.647  1.0
  Ta  Ta14  1  0.000  0.674  0.147  1.0
  Ta  Ta15  1  0.000  0.326  0.853  1.0
  Ta  Ta16  1  0.500  0.153  0.788  1.0
  Ta  Ta17  1  0.500  0.847  0.212  1.0
  Ta  Ta18  1  0.000  0.653  0.712  1.0
  Ta  Ta19  1  0.000  0.347  0.288  1.0
  Ta  Ta20  1  0.500  0.500  0.500  1.0
  Ta  Ta21  1  0.000  0.000  0.000  1.0
  Co  Co22  1  0.000  0.093  0.872  1.0
  Co  Co23  1  0.000  0.907  0.128  1.0
  Co  Co24  1  0.500  0.593  0.628  1.0
  Co  Co25  1  0.500  0.407  0.372  1.0
  Se  Se26  1  0.500  0.296  0.555  1.0
  Se  Se27  1  0.500  0.704  0.445  1.0
  Se  Se28  1  0.000  0.796  0.945  1.0
  Se  Se29  1  0.000  0.204  0.055  1.0
  Se  Se30  1  0.500  0.040  0.674  1.0
  Se  Se31  1  0.500  0.960  0.326  1.0
  Se  Se32  1  0.000  0.540  0.826  1.0
  Se  Se33  1  0.000  0.460  0.174  1.0
  Se  Se34  1  0.500  0.390  0.946  1.0
  Se  Se35  1  0.500  0.610  0.054  1.0
  Se  Se36  1  0.000  0.890  0.554  1.0
  Se  Se37  1  0.000  0.110  0.446  1.0
  Se  Se38  1  0.000  0.284  0.714  1.0
  Se  Se39  1  0.000  0.716  0.286  1.0
  Se  Se40  1  0.500  0.784  0.786  1.0
  Se  Se41  1  0.500  0.216  0.214  1.0
[/CIF]
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