The crystal structure described by K3Cu3Nb2S8 crystallizes in the monoclinic C2/c space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one S(4), three equivalent S(1), and three equivalent S(2) atoms. In the second K site, K(2) is bonded in a body-centered cubic geometry to two equivalent S(1), two equivalent S(4), and four equivalent S(3) atoms. Nb(1) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form NbS4 tetrahedra that share  an edgeedge with one Cu(2)S4 tetrahedra and edges with two equivalent Cu(1)S4 tetrahedra. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form distorted CuS4 tetrahedra that share corners with two equivalent Cu(2)S4 tetrahedra and edges with two equivalent Nb(1)S4 tetrahedra. In the second Cu site, Cu(2) is bonded to two equivalent S(3) and two equivalent S(4) atoms to form distorted CuS4 tetrahedra that share corners with four equivalent Cu(1)S4 tetrahedra and edges with two equivalent Nb(1)S4 tetrahedra. There are four inequivalent S sites. In the first S site, S(1) is bonded to one K(2), three equivalent K(1), one Nb(1), and one Cu(1) atom to form a mixture of distorted corner and edge-sharing SK4NbCu octahedra. The corner-sharing octahedral tilt angles range from 0-70°. In the second S site, S(2) is bonded in a 5-coordinate geometry to three equivalent K(1), one Nb(1), and one Cu(1) atom. In the third S site, S(3) is bonded in a 5-coordinate geometry to two equivalent K(2), one Nb(1), one Cu(1), and one Cu(2) atom. In the fourth S site, S(4) is bonded in a 5-coordinate geometry to one K(1), one K(2), one Nb(1), one Cu(1), and one Cu(2) atom. is represented by the CIF file [CIF]
data_K3Nb2Cu3S8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.249
_cell_length_b   12.249
_cell_length_c   14.524
_cell_angle_alpha   60.544
_cell_angle_beta   60.544
_cell_angle_gamma   26.302
_symmetry_Int_Tables_number   1
_cell_volume   833.348
_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  0.267  0.347  0.595  1.0
  K  K1  1  0.653  0.733  0.905  1.0
  K  K2  1  0.733  0.653  0.405  1.0
  K  K3  1  0.000  0.000  0.500  1.0
  K  K4  1  0.000  0.000  0.000  1.0
  K  K5  1  0.347  0.267  0.095  1.0
  Nb  Nb6  1  0.842  0.408  0.721  1.0
  Nb  Nb7  1  0.408  0.842  0.221  1.0
  Nb  Nb8  1  0.592  0.158  0.779  1.0
  Nb  Nb9  1  0.158  0.592  0.279  1.0
  Cu  Cu10  1  0.340  0.904  0.720  1.0
  Cu  Cu11  1  0.660  0.096  0.280  1.0
  Cu  Cu12  1  0.904  0.340  0.220  1.0
  Cu  Cu13  1  0.279  0.721  0.250  1.0
  Cu  Cu14  1  0.096  0.660  0.780  1.0
  Cu  Cu15  1  0.721  0.279  0.750  1.0
  S  S16  1  0.186  0.126  0.313  1.0
  S  S17  1  0.324  0.259  0.390  1.0
  S  S18  1  0.518  0.559  0.839  1.0
  S  S19  1  0.126  0.186  0.813  1.0
  S  S20  1  0.874  0.814  0.187  1.0
  S  S21  1  0.135  0.044  0.129  1.0
  S  S22  1  0.559  0.518  0.339  1.0
  S  S23  1  0.441  0.482  0.661  1.0
  S  S24  1  0.044  0.135  0.629  1.0
  S  S25  1  0.259  0.324  0.890  1.0
  S  S26  1  0.482  0.441  0.161  1.0
  S  S27  1  0.676  0.741  0.610  1.0
  S  S28  1  0.814  0.874  0.687  1.0
  S  S29  1  0.741  0.676  0.110  1.0
  S  S30  1  0.956  0.865  0.371  1.0
  S  S31  1  0.865  0.956  0.871  1.0
[/CIF]
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The crystal structure described by K3Cu3Nb2S8 crystallizes in the monoclinic C2/c space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one S(4), three equivalent S(1), and three equivalent S(2) atoms. In the second K site, K(2) is bonded in a body-centered cubic geometry to two equivalent S(1), two equivalent S(4), and four equivalent S(3) atoms. Nb(1) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form NbS4 tetrahedra that share  an edgeedge with one Cu(2)S4 tetrahedra and edges with two equivalent Cu(1)S4 tetrahedra. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form distorted CuS4 tetrahedra that share corners with two equivalent Cu(2)S4 tetrahedra and edges with two equivalent Nb(1)S4 tetrahedra. In the second Cu site, Cu(2) is bonded to two equivalent S(3) and two equivalent S(4) atoms to form distorted CuS4 tetrahedra that share corners with four equivalent Cu(1)S4 tetrahedra and edges with two equivalent Nb(1)S4 tetrahedra. There are four inequivalent S sites. In the first S site, S(1) is bonded to one K(2), three equivalent K(1), one Nb(1), and one Cu(1) atom to form a mixture of distorted corner and edge-sharing SK4NbCu octahedra. The corner-sharing octahedral tilt angles range from 0-70°. In the second S site, S(2) is bonded in a 5-coordinate geometry to three equivalent K(1), one Nb(1), and one Cu(1) atom. In the third S site, S(3) is bonded in a 5-coordinate geometry to two equivalent K(2), one Nb(1), one Cu(1), and one Cu(2) atom. In the fourth S site, S(4) is bonded in a 5-coordinate geometry to one K(1), one K(2), one Nb(1), one Cu(1), and one Cu(2) atom. is represented by the CIF file [CIF]
data_K3Nb2Cu3S8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.249
_cell_length_b   12.249
_cell_length_c   14.524
_cell_angle_alpha   60.544
_cell_angle_beta   60.544
_cell_angle_gamma   26.302
_symmetry_Int_Tables_number   1
_cell_volume   833.348
_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  0.267  0.347  0.595  1.0
  K  K1  1  0.653  0.733  0.905  1.0
  K  K2  1  0.733  0.653  0.405  1.0
  K  K3  1  0.000  0.000  0.500  1.0
  K  K4  1  0.000  0.000  0.000  1.0
  K  K5  1  0.347  0.267  0.095  1.0
  Nb  Nb6  1  0.842  0.408  0.721  1.0
  Nb  Nb7  1  0.408  0.842  0.221  1.0
  Nb  Nb8  1  0.592  0.158  0.779  1.0
  Nb  Nb9  1  0.158  0.592  0.279  1.0
  Cu  Cu10  1  0.340  0.904  0.720  1.0
  Cu  Cu11  1  0.660  0.096  0.280  1.0
  Cu  Cu12  1  0.904  0.340  0.220  1.0
  Cu  Cu13  1  0.279  0.721  0.250  1.0
  Cu  Cu14  1  0.096  0.660  0.780  1.0
  Cu  Cu15  1  0.721  0.279  0.750  1.0
  S  S16  1  0.186  0.126  0.313  1.0
  S  S17  1  0.324  0.259  0.390  1.0
  S  S18  1  0.518  0.559  0.839  1.0
  S  S19  1  0.126  0.186  0.813  1.0
  S  S20  1  0.874  0.814  0.187  1.0
  S  S21  1  0.135  0.044  0.129  1.0
  S  S22  1  0.559  0.518  0.339  1.0
  S  S23  1  0.441  0.482  0.661  1.0
  S  S24  1  0.044  0.135  0.629  1.0
  S  S25  1  0.259  0.324  0.890  1.0
  S  S26  1  0.482  0.441  0.161  1.0
  S  S27  1  0.676  0.741  0.610  1.0
  S  S28  1  0.814  0.874  0.687  1.0
  S  S29  1  0.741  0.676  0.110  1.0
  S  S30  1  0.956  0.865  0.371  1.0
  S  S31  1  0.865  0.956  0.871  1.0
[/CIF]
.