The material described by K2(NbSe2)3 crystallizes in the orthorhombic Amm2 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to two equivalent Se(4) and four equivalent Se(3) atoms. In the second K site, K(2) is bonded in a 6-coordinate geometry to two equivalent Se(2) and four equivalent Se(1) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one Se(2), one Se(4), two equivalent Se(1), and two equivalent Se(3) atoms to form distorted edge-sharing NbSe6 pentagonal pyramids. In the second Nb site, Nb(2) is bonded to one Se(2), one Se(4), two equivalent Se(1), and two equivalent Se(3) atoms to form distorted edge-sharing NbSe6 pentagonal pyramids. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent K(2), one Nb(2), and two equivalent Nb(1) atoms to form a mixture of distorted corner, edge, and face-sharing SeK2Nb3 trigonal bipyramids. In the second Se site, Se(2) is bonded to two equivalent K(2), one Nb(2), and two equivalent Nb(1) atoms to form a mixture of distorted corner, edge, and face-sharing SeK2Nb3 trigonal bipyramids. In the third Se site, Se(3) is bonded to two equivalent K(1), one Nb(2), and two equivalent Nb(1) atoms to form a mixture of distorted corner, edge, and face-sharing SeK2Nb3 square pyramids. In the fourth Se site, Se(4) is bonded to two equivalent K(1), one Nb(2), and two equivalent Nb(1) atoms to form a mixture of distorted corner, edge, and face-sharing SeK2Nb3 square pyramids. is represented by the CIF file [CIF]
data_K2(NbSe2)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.169
_cell_length_b   6.169
_cell_length_c   16.502
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   119.999
_symmetry_Int_Tables_number   1
_cell_volume   543.958
_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  0.000  0.667  0.500  1.0
  K  K1  1  0.667  0.000  0.500  1.0
  K  K2  1  0.667  0.333  0.000  1.0
  K  K3  1  0.333  0.667  0.000  1.0
  Nb  Nb4  1  0.668  0.333  0.250  1.0
  Nb  Nb5  1  0.999  0.999  0.251  1.0
  Nb  Nb6  1  0.333  0.668  0.250  1.0
  Nb  Nb7  1  0.668  0.333  0.750  1.0
  Nb  Nb8  1  0.999  0.999  0.749  1.0
  Nb  Nb9  1  0.333  0.668  0.750  1.0
  Se  Se10  1  0.000  0.331  0.151  1.0
  Se  Se11  1  0.331  0.000  0.151  1.0
  Se  Se12  1  0.669  0.669  0.151  1.0
  Se  Se13  1  0.000  0.331  0.849  1.0
  Se  Se14  1  0.331  0.000  0.849  1.0
  Se  Se15  1  0.669  0.669  0.849  1.0
  Se  Se16  1  0.002  0.334  0.349  1.0
  Se  Se17  1  0.334  0.002  0.349  1.0
  Se  Se18  1  0.664  0.664  0.349  1.0
  Se  Se19  1  0.002  0.334  0.651  1.0
  Se  Se20  1  0.334  0.002  0.651  1.0
  Se  Se21  1  0.664  0.664  0.651  1.0
[/CIF]
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The material described by K2(NbSe2)3 crystallizes in the orthorhombic Amm2 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to two equivalent Se(4) and four equivalent Se(3) atoms. In the second K site, K(2) is bonded in a 6-coordinate geometry to two equivalent Se(2) and four equivalent Se(1) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one Se(2), one Se(4), two equivalent Se(1), and two equivalent Se(3) atoms to form distorted edge-sharing NbSe6 pentagonal pyramids. In the second Nb site, Nb(2) is bonded to one Se(2), one Se(4), two equivalent Se(1), and two equivalent Se(3) atoms to form distorted edge-sharing NbSe6 pentagonal pyramids. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded to two equivalent K(2), one Nb(2), and two equivalent Nb(1) atoms to form a mixture of distorted corner, edge, and face-sharing SeK2Nb3 trigonal bipyramids. In the second Se site, Se(2) is bonded to two equivalent K(2), one Nb(2), and two equivalent Nb(1) atoms to form a mixture of distorted corner, edge, and face-sharing SeK2Nb3 trigonal bipyramids. In the third Se site, Se(3) is bonded to two equivalent K(1), one Nb(2), and two equivalent Nb(1) atoms to form a mixture of distorted corner, edge, and face-sharing SeK2Nb3 square pyramids. In the fourth Se site, Se(4) is bonded to two equivalent K(1), one Nb(2), and two equivalent Nb(1) atoms to form a mixture of distorted corner, edge, and face-sharing SeK2Nb3 square pyramids. is represented by the CIF file [CIF]
data_K2(NbSe2)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.169
_cell_length_b   6.169
_cell_length_c   16.502
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   119.999
_symmetry_Int_Tables_number   1
_cell_volume   543.958
_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  0.000  0.667  0.500  1.0
  K  K1  1  0.667  0.000  0.500  1.0
  K  K2  1  0.667  0.333  0.000  1.0
  K  K3  1  0.333  0.667  0.000  1.0
  Nb  Nb4  1  0.668  0.333  0.250  1.0
  Nb  Nb5  1  0.999  0.999  0.251  1.0
  Nb  Nb6  1  0.333  0.668  0.250  1.0
  Nb  Nb7  1  0.668  0.333  0.750  1.0
  Nb  Nb8  1  0.999  0.999  0.749  1.0
  Nb  Nb9  1  0.333  0.668  0.750  1.0
  Se  Se10  1  0.000  0.331  0.151  1.0
  Se  Se11  1  0.331  0.000  0.151  1.0
  Se  Se12  1  0.669  0.669  0.151  1.0
  Se  Se13  1  0.000  0.331  0.849  1.0
  Se  Se14  1  0.331  0.000  0.849  1.0
  Se  Se15  1  0.669  0.669  0.849  1.0
  Se  Se16  1  0.002  0.334  0.349  1.0
  Se  Se17  1  0.334  0.002  0.349  1.0
  Se  Se18  1  0.664  0.664  0.349  1.0
  Se  Se19  1  0.002  0.334  0.651  1.0
  Se  Se20  1  0.334  0.002  0.651  1.0
  Se  Se21  1  0.664  0.664  0.651  1.0
[/CIF]
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