The crystal structure described by Nb4CoSe8 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 6-coordinate geometry to six equivalent Se(2) atoms. In the second Nb site, Nb(2) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form distorted NbSe6 pentagonal pyramids that share corners with four equivalent Co(1)Se6 octahedra and edges with four equivalent Nb(2)Se6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 49°. Co(1) is bonded to six equivalent Se(2) atoms to form CoSe6 octahedra that share corners with twelve equivalent Nb(2)Se6 pentagonal pyramids. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 3-coordinate geometry to three equivalent Nb(2) atoms. In the second Se site, Se(2) is bonded in a rectangular see-saw-like geometry to one Nb(1), two equivalent Nb(2), and one Co(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Nb4CoSe8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.996
_cell_length_b   6.996
_cell_length_c   12.605
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   534.270
_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
  Nb  Nb0  1  1.000  1.000  0.250  1.0
  Nb  Nb1  1  0.000  0.000  0.750  1.0
  Nb  Nb2  1  0.510  0.020  0.250  1.0
  Nb  Nb3  1  0.980  0.490  0.250  1.0
  Nb  Nb4  1  0.510  0.490  0.250  1.0
  Nb  Nb5  1  0.490  0.980  0.750  1.0
  Nb  Nb6  1  0.020  0.510  0.750  1.0
  Nb  Nb7  1  0.490  0.510  0.750  1.0
  Co  Co8  1  1.000  0.000  0.500  1.0
  Co  Co9  1  1.000  0.000  1.000  1.0
  Se  Se10  1  0.333  0.667  0.888  1.0
  Se  Se11  1  0.667  0.333  0.112  1.0
  Se  Se12  1  0.667  0.333  0.388  1.0
  Se  Se13  1  0.333  0.667  0.612  1.0
  Se  Se14  1  0.168  0.832  0.380  1.0
  Se  Se15  1  0.168  0.336  0.380  1.0
  Se  Se16  1  0.664  0.832  0.380  1.0
  Se  Se17  1  0.832  0.168  0.620  1.0
  Se  Se18  1  0.832  0.664  0.620  1.0
  Se  Se19  1  0.336  0.168  0.620  1.0
  Se  Se20  1  0.832  0.168  0.880  1.0
  Se  Se21  1  0.832  0.664  0.880  1.0
  Se  Se22  1  0.336  0.168  0.880  1.0
  Se  Se23  1  0.168  0.832  0.120  1.0
  Se  Se24  1  0.168  0.336  0.120  1.0
  Se  Se25  1  0.664  0.832  0.120  1.0
[/CIF]
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The crystal structure described by Nb4CoSe8 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 6-coordinate geometry to six equivalent Se(2) atoms. In the second Nb site, Nb(2) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form distorted NbSe6 pentagonal pyramids that share corners with four equivalent Co(1)Se6 octahedra and edges with four equivalent Nb(2)Se6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 49°. Co(1) is bonded to six equivalent Se(2) atoms to form CoSe6 octahedra that share corners with twelve equivalent Nb(2)Se6 pentagonal pyramids. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 3-coordinate geometry to three equivalent Nb(2) atoms. In the second Se site, Se(2) is bonded in a rectangular see-saw-like geometry to one Nb(1), two equivalent Nb(2), and one Co(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Nb4CoSe8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.996
_cell_length_b   6.996
_cell_length_c   12.605
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   534.270
_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
  Nb  Nb0  1  1.000  1.000  0.250  1.0
  Nb  Nb1  1  0.000  0.000  0.750  1.0
  Nb  Nb2  1  0.510  0.020  0.250  1.0
  Nb  Nb3  1  0.980  0.490  0.250  1.0
  Nb  Nb4  1  0.510  0.490  0.250  1.0
  Nb  Nb5  1  0.490  0.980  0.750  1.0
  Nb  Nb6  1  0.020  0.510  0.750  1.0
  Nb  Nb7  1  0.490  0.510  0.750  1.0
  Co  Co8  1  1.000  0.000  0.500  1.0
  Co  Co9  1  1.000  0.000  1.000  1.0
  Se  Se10  1  0.333  0.667  0.888  1.0
  Se  Se11  1  0.667  0.333  0.112  1.0
  Se  Se12  1  0.667  0.333  0.388  1.0
  Se  Se13  1  0.333  0.667  0.612  1.0
  Se  Se14  1  0.168  0.832  0.380  1.0
  Se  Se15  1  0.168  0.336  0.380  1.0
  Se  Se16  1  0.664  0.832  0.380  1.0
  Se  Se17  1  0.832  0.168  0.620  1.0
  Se  Se18  1  0.832  0.664  0.620  1.0
  Se  Se19  1  0.336  0.168  0.620  1.0
  Se  Se20  1  0.832  0.168  0.880  1.0
  Se  Se21  1  0.832  0.664  0.880  1.0
  Se  Se22  1  0.336  0.168  0.880  1.0
  Se  Se23  1  0.168  0.832  0.120  1.0
  Se  Se24  1  0.168  0.336  0.120  1.0
  Se  Se25  1  0.664  0.832  0.120  1.0
[/CIF]
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