The material described by Nb6SnSe8 crystallizes in the trigonal P-3 space group. Nb(1) is bonded in a 6-coordinate geometry to two equivalent Se(2) and four equivalent Se(1) atoms. Sn(1) is bonded in a 6-coordinate geometry to six equivalent Se(1) atoms. There are two inequivalent Se sites. In the first Se site, Se(2) is bonded to six equivalent Nb(1) atoms to form distorted face-sharing SeNb6 pentagonal pyramids. In the second Se site, Se(1) is bonded in a 4-coordinate geometry to four equivalent Nb(1) and one Sn(1) atom. is represented by the CIF file [CIF]
data_Nb6SnSe8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.112
_cell_length_b   10.112
_cell_length_c   3.499
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   309.818
_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
  Nb  Nb0  1  0.106  0.487  0.749  1.0
  Nb  Nb1  1  0.513  0.619  0.749  1.0
  Nb  Nb2  1  0.381  0.894  0.749  1.0
  Nb  Nb3  1  0.894  0.513  0.251  1.0
  Nb  Nb4  1  0.487  0.381  0.251  1.0
  Nb  Nb5  1  0.619  0.106  0.251  1.0
  Sn  Sn6  1  0.000  0.000  0.500  1.0
  Se  Se7  1  0.278  0.336  0.751  1.0
  Se  Se8  1  0.664  0.941  0.751  1.0
  Se  Se9  1  0.059  0.722  0.751  1.0
  Se  Se10  1  0.722  0.664  0.249  1.0
  Se  Se11  1  0.336  0.059  0.249  1.0
  Se  Se12  1  0.941  0.278  0.249  1.0
  Se  Se13  1  0.667  0.333  0.750  1.0
  Se  Se14  1  0.333  0.667  0.250  1.0
[/CIF]
.
The material described by Nb6SnSe8 crystallizes in the trigonal P-3 space group. Nb(1) is bonded in a 6-coordinate geometry to two equivalent Se(2) and four equivalent Se(1) atoms. Sn(1) is bonded in a 6-coordinate geometry to six equivalent Se(1) atoms. There are two inequivalent Se sites. In the first Se site, Se(2) is bonded to six equivalent Nb(1) atoms to form distorted face-sharing SeNb6 pentagonal pyramids. In the second Se site, Se(1) is bonded in a 4-coordinate geometry to four equivalent Nb(1) and one Sn(1) atom. is represented by the CIF file [CIF]
data_Nb6SnSe8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.112
_cell_length_b   10.112
_cell_length_c   3.499
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   309.818
_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
  Nb  Nb0  1  0.106  0.487  0.749  1.0
  Nb  Nb1  1  0.513  0.619  0.749  1.0
  Nb  Nb2  1  0.381  0.894  0.749  1.0
  Nb  Nb3  1  0.894  0.513  0.251  1.0
  Nb  Nb4  1  0.487  0.381  0.251  1.0
  Nb  Nb5  1  0.619  0.106  0.251  1.0
  Sn  Sn6  1  0.000  0.000  0.500  1.0
  Se  Se7  1  0.278  0.336  0.751  1.0
  Se  Se8  1  0.664  0.941  0.751  1.0
  Se  Se9  1  0.059  0.722  0.751  1.0
  Se  Se10  1  0.722  0.664  0.249  1.0
  Se  Se11  1  0.336  0.059  0.249  1.0
  Se  Se12  1  0.941  0.278  0.249  1.0
  Se  Se13  1  0.667  0.333  0.750  1.0
  Se  Se14  1  0.333  0.667  0.250  1.0
[/CIF]
.