The structure described by K2MgNb2(CuS2)4 crystallizes in the triclinic P1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one Mg(1), one S(1), one S(3), one S(4), one S(5), and two equivalent S(7) atoms. In the second K site, K(2) is bonded in a 6-coordinate geometry to one S(2), one S(3), one S(4), one S(6), and two equivalent S(8) atoms. Mg(1) is bonded in a 3-coordinate geometry to one K(1), one S(3), one S(4), and one S(6) atom. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 4-coordinate geometry to one S(1), one S(3), one S(6), and one S(8) atom. In the second Nb site, Nb(2) is bonded to one S(2), one S(4), one S(5), and one S(7) atom to form distorted NbS4 tetrahedra that share  an edgeedge with one Cu(1)S4 tetrahedra,  an edgeedge with one Cu(2)S4 tetrahedra, and edges with two equivalent Cu(4)S4 tetrahedra. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(1), one S(2), one S(5), and one S(6) atom to form distorted CuS4 tetrahedra that share corners with two equivalent Cu(2)S4 tetrahedra, corners with two equivalent Cu(4)S4 tetrahedra, and  an edgeedge with one Nb(2)S4 tetrahedra. In the second Cu site, Cu(2) is bonded to one S(1), one S(2), one S(7), and one S(8) atom to form distorted CuS4 tetrahedra that share corners with two equivalent Cu(1)S4 tetrahedra, corners with two equivalent Cu(4)S4 tetrahedra, and  an edgeedge with one Nb(2)S4 tetrahedra. In the third Cu site, Cu(3) is bonded in a 4-coordinate geometry to one S(1), one S(3), one S(6), and one S(8) atom. In the fourth Cu site, Cu(4) is bonded to one S(2), one S(4), one S(5), and one S(7) atom to form distorted CuS4 tetrahedra that share corners with two equivalent Cu(1)S4 tetrahedra, corners with two equivalent Cu(2)S4 tetrahedra, and edges with two equivalent Nb(2)S4 tetrahedra. There are eight inequivalent S sites. In the first S site, S(1) is bonded in a distorted trigonal bipyramidal geometry to one K(1), one Nb(1), one Cu(1), one Cu(2), and one Cu(3) atom. In the second S site, S(2) is bonded in a distorted pentagonal planar geometry to one K(2), one Nb(2), one Cu(1), one Cu(2), and one Cu(4) atom. In the third S site, S(3) is bonded in a 5-coordinate geometry to one K(1), one K(2), one Mg(1), one Nb(1), and one Cu(3) atom. In the fourth S site, S(4) is bonded in a 5-coordinate geometry to one K(1), one K(2), one Mg(1), one Nb(2), and one Cu(4) atom. In the fifth S site, S(5) is bonded in a 4-coordinate geometry to one K(1), one Nb(2), one Cu(1), and one Cu(4) atom. In the sixth S site, S(6) is bonded in a 5-coordinate geometry to one K(2), one Mg(1), one Nb(1), one Cu(1), and one Cu(3) atom. In the seventh S site, S(7) is bonded in a 5-coordinate geometry to two equivalent K(1), one Nb(2), one Cu(2), and one Cu(4) atom. In the eighth S site, S(8) is bonded in a 5-coordinate geometry to two equivalent K(2), one Nb(1), one Cu(2), and one Cu(3) atom. is represented by the CIF card [CIF]
data_K2MgNb2(CuS2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.534
_cell_length_b   7.874
_cell_length_c   9.948
_cell_angle_alpha   83.041
_cell_angle_beta   103.764
_cell_angle_gamma   85.772
_symmetry_Int_Tables_number   1
_cell_volume   415.548
_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
  K  K0  1  0.684  0.815  0.705  1.0
  K  K1  1  0.864  0.191  0.319  1.0
  Mg  Mg2  1  0.372  0.549  0.440  1.0
  Nb  Nb3  1  0.611  0.753  0.253  1.0
  Nb  Nb4  1  0.390  0.257  0.777  1.0
  Cu  Cu5  1  0.454  0.475  0.983  1.0
  Cu  Cu6  1  0.485  0.992  0.007  1.0
  Cu  Cu7  1  0.081  0.755  0.195  1.0
  Cu  Cu8  1  0.897  0.266  0.791  1.0
  S  S9  1  0.713  0.723  0.034  1.0
  S  S10  1  0.715  0.236  0.979  1.0
  S  S11  1  0.979  0.740  0.430  1.0
  S  S12  1  0.568  0.270  0.584  1.0
  S  S13  1  0.136  0.500  0.785  1.0
  S  S14  1  0.365  0.512  0.196  1.0
  S  S15  1  0.171  0.020  0.801  1.0
  S  S16  1  0.328  0.997  0.207  1.0
[/CIF]
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The structure described by K2MgNb2(CuS2)4 crystallizes in the triclinic P1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one Mg(1), one S(1), one S(3), one S(4), one S(5), and two equivalent S(7) atoms. In the second K site, K(2) is bonded in a 6-coordinate geometry to one S(2), one S(3), one S(4), one S(6), and two equivalent S(8) atoms. Mg(1) is bonded in a 3-coordinate geometry to one K(1), one S(3), one S(4), and one S(6) atom. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 4-coordinate geometry to one S(1), one S(3), one S(6), and one S(8) atom. In the second Nb site, Nb(2) is bonded to one S(2), one S(4), one S(5), and one S(7) atom to form distorted NbS4 tetrahedra that share  an edgeedge with one Cu(1)S4 tetrahedra,  an edgeedge with one Cu(2)S4 tetrahedra, and edges with two equivalent Cu(4)S4 tetrahedra. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(1), one S(2), one S(5), and one S(6) atom to form distorted CuS4 tetrahedra that share corners with two equivalent Cu(2)S4 tetrahedra, corners with two equivalent Cu(4)S4 tetrahedra, and  an edgeedge with one Nb(2)S4 tetrahedra. In the second Cu site, Cu(2) is bonded to one S(1), one S(2), one S(7), and one S(8) atom to form distorted CuS4 tetrahedra that share corners with two equivalent Cu(1)S4 tetrahedra, corners with two equivalent Cu(4)S4 tetrahedra, and  an edgeedge with one Nb(2)S4 tetrahedra. In the third Cu site, Cu(3) is bonded in a 4-coordinate geometry to one S(1), one S(3), one S(6), and one S(8) atom. In the fourth Cu site, Cu(4) is bonded to one S(2), one S(4), one S(5), and one S(7) atom to form distorted CuS4 tetrahedra that share corners with two equivalent Cu(1)S4 tetrahedra, corners with two equivalent Cu(2)S4 tetrahedra, and edges with two equivalent Nb(2)S4 tetrahedra. There are eight inequivalent S sites. In the first S site, S(1) is bonded in a distorted trigonal bipyramidal geometry to one K(1), one Nb(1), one Cu(1), one Cu(2), and one Cu(3) atom. In the second S site, S(2) is bonded in a distorted pentagonal planar geometry to one K(2), one Nb(2), one Cu(1), one Cu(2), and one Cu(4) atom. In the third S site, S(3) is bonded in a 5-coordinate geometry to one K(1), one K(2), one Mg(1), one Nb(1), and one Cu(3) atom. In the fourth S site, S(4) is bonded in a 5-coordinate geometry to one K(1), one K(2), one Mg(1), one Nb(2), and one Cu(4) atom. In the fifth S site, S(5) is bonded in a 4-coordinate geometry to one K(1), one Nb(2), one Cu(1), and one Cu(4) atom. In the sixth S site, S(6) is bonded in a 5-coordinate geometry to one K(2), one Mg(1), one Nb(1), one Cu(1), and one Cu(3) atom. In the seventh S site, S(7) is bonded in a 5-coordinate geometry to two equivalent K(1), one Nb(2), one Cu(2), and one Cu(4) atom. In the eighth S site, S(8) is bonded in a 5-coordinate geometry to two equivalent K(2), one Nb(1), one Cu(2), and one Cu(3) atom. is represented by the CIF card [CIF]
data_K2MgNb2(CuS2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.534
_cell_length_b   7.874
_cell_length_c   9.948
_cell_angle_alpha   83.041
_cell_angle_beta   103.764
_cell_angle_gamma   85.772
_symmetry_Int_Tables_number   1
_cell_volume   415.548
_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
  K  K0  1  0.684  0.815  0.705  1.0
  K  K1  1  0.864  0.191  0.319  1.0
  Mg  Mg2  1  0.372  0.549  0.440  1.0
  Nb  Nb3  1  0.611  0.753  0.253  1.0
  Nb  Nb4  1  0.390  0.257  0.777  1.0
  Cu  Cu5  1  0.454  0.475  0.983  1.0
  Cu  Cu6  1  0.485  0.992  0.007  1.0
  Cu  Cu7  1  0.081  0.755  0.195  1.0
  Cu  Cu8  1  0.897  0.266  0.791  1.0
  S  S9  1  0.713  0.723  0.034  1.0
  S  S10  1  0.715  0.236  0.979  1.0
  S  S11  1  0.979  0.740  0.430  1.0
  S  S12  1  0.568  0.270  0.584  1.0
  S  S13  1  0.136  0.500  0.785  1.0
  S  S14  1  0.365  0.512  0.196  1.0
  S  S15  1  0.171  0.020  0.801  1.0
  S  S16  1  0.328  0.997  0.207  1.0
[/CIF]
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