The material structure described by Nb4VSe8 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to six equivalent Se(2) atoms to form distorted NbSe6 pentagonal pyramids that share edges with six equivalent Nb(2)Se6 pentagonal pyramids and faces with two equivalent V(1)Se6 octahedra. 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 V(1)Se6 octahedra, edges with two equivalent Nb(1)Se6 pentagonal pyramids, and edges with four equivalent Nb(2)Se6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 48°. V(1) is bonded to six equivalent Se(2) atoms to form VSe6 octahedra that share corners with twelve equivalent Nb(2)Se6 pentagonal pyramids and faces with two equivalent Nb(1)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 V(1) atom. is represented by the CIF file [CIF]
data_Nb4VSe8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.995
_cell_length_b   6.995
_cell_length_c   12.830
_cell_angle_alpha   90.001
_cell_angle_beta   89.999
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   543.683
_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  0.000  0.000  0.250  1.0
  Nb  Nb1  1  1.000  0.000  0.750  1.0
  Nb  Nb2  1  0.508  0.016  0.250  1.0
  Nb  Nb3  1  0.492  0.984  0.750  1.0
  Nb  Nb4  1  0.984  0.492  0.250  1.0
  Nb  Nb5  1  0.016  0.508  0.750  1.0
  Nb  Nb6  1  0.508  0.492  0.250  1.0
  Nb  Nb7  1  0.492  0.508  0.750  1.0
  V  V8  1  0.000  1.000  1.000  1.0
  V  V9  1  0.000  1.000  0.500  1.0
  Se  Se10  1  0.333  0.667  0.616  1.0
  Se  Se11  1  0.667  0.333  0.384  1.0
  Se  Se12  1  0.667  0.333  0.116  1.0
  Se  Se13  1  0.333  0.667  0.884  1.0
  Se  Se14  1  0.168  0.335  0.121  1.0
  Se  Se15  1  0.832  0.665  0.879  1.0
  Se  Se16  1  0.665  0.832  0.121  1.0
  Se  Se17  1  0.832  0.665  0.621  1.0
  Se  Se18  1  0.335  0.168  0.879  1.0
  Se  Se19  1  0.168  0.335  0.379  1.0
  Se  Se20  1  0.168  0.832  0.121  1.0
  Se  Se21  1  0.335  0.168  0.621  1.0
  Se  Se22  1  0.832  0.168  0.879  1.0
  Se  Se23  1  0.665  0.832  0.379  1.0
  Se  Se24  1  0.832  0.168  0.621  1.0
  Se  Se25  1  0.168  0.832  0.379  1.0
[/CIF]
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The material structure described by Nb4VSe8 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to six equivalent Se(2) atoms to form distorted NbSe6 pentagonal pyramids that share edges with six equivalent Nb(2)Se6 pentagonal pyramids and faces with two equivalent V(1)Se6 octahedra. 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 V(1)Se6 octahedra, edges with two equivalent Nb(1)Se6 pentagonal pyramids, and edges with four equivalent Nb(2)Se6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 48°. V(1) is bonded to six equivalent Se(2) atoms to form VSe6 octahedra that share corners with twelve equivalent Nb(2)Se6 pentagonal pyramids and faces with two equivalent Nb(1)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 V(1) atom. is represented by the CIF file [CIF]
data_Nb4VSe8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.995
_cell_length_b   6.995
_cell_length_c   12.830
_cell_angle_alpha   90.001
_cell_angle_beta   89.999
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   543.683
_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  0.000  0.000  0.250  1.0
  Nb  Nb1  1  1.000  0.000  0.750  1.0
  Nb  Nb2  1  0.508  0.016  0.250  1.0
  Nb  Nb3  1  0.492  0.984  0.750  1.0
  Nb  Nb4  1  0.984  0.492  0.250  1.0
  Nb  Nb5  1  0.016  0.508  0.750  1.0
  Nb  Nb6  1  0.508  0.492  0.250  1.0
  Nb  Nb7  1  0.492  0.508  0.750  1.0
  V  V8  1  0.000  1.000  1.000  1.0
  V  V9  1  0.000  1.000  0.500  1.0
  Se  Se10  1  0.333  0.667  0.616  1.0
  Se  Se11  1  0.667  0.333  0.384  1.0
  Se  Se12  1  0.667  0.333  0.116  1.0
  Se  Se13  1  0.333  0.667  0.884  1.0
  Se  Se14  1  0.168  0.335  0.121  1.0
  Se  Se15  1  0.832  0.665  0.879  1.0
  Se  Se16  1  0.665  0.832  0.121  1.0
  Se  Se17  1  0.832  0.665  0.621  1.0
  Se  Se18  1  0.335  0.168  0.879  1.0
  Se  Se19  1  0.168  0.335  0.379  1.0
  Se  Se20  1  0.168  0.832  0.121  1.0
  Se  Se21  1  0.335  0.168  0.621  1.0
  Se  Se22  1  0.832  0.168  0.879  1.0
  Se  Se23  1  0.665  0.832  0.379  1.0
  Se  Se24  1  0.832  0.168  0.621  1.0
  Se  Se25  1  0.168  0.832  0.379  1.0
[/CIF]
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