The structure described by Rb4MgNb2(CuS4)2 crystallizes in the triclinic P1 space group. There are four inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 9-coordinate geometry to one Mg(1), one S(2), one S(3), one S(5), one S(8), two equivalent S(6), and two equivalent S(7) atoms. In the second Rb site, Rb(2) is bonded in a 7-coordinate geometry to one S(1), one S(4), one S(6), two equivalent S(5), and two equivalent S(8) atoms. In the third Rb site, Rb(3) is bonded in a 6-coordinate geometry to one S(1), one S(4), two equivalent S(2), and two equivalent S(3) atoms. In the fourth Rb site, Rb(4) is bonded in a 7-coordinate geometry to one S(2), one S(5), one S(8), two equivalent S(1), and two equivalent S(4) atoms. Mg(1) is bonded in a 3-coordinate geometry to one Rb(1), one S(3), one S(6), and one S(7) atom. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one S(5), one S(6), one S(7), and one S(8) atom to form NbS4 tetrahedra that share edges with two equivalent Cu(1)S4 tetrahedra. In the second Nb site, Nb(2) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form NbS4 tetrahedra that share edges with two equivalent Cu(2)S4 tetrahedra. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(5), one S(6), one S(7), and one S(8) atom to form distorted CuS4 tetrahedra that share edges with two equivalent Nb(1)S4 tetrahedra. In the second Cu site, Cu(2) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form distorted CuS4 tetrahedra that share 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 6-coordinate geometry to one Rb(2), one Rb(3), two equivalent Rb(4), one Nb(2), and one Cu(2) atom. In the second S site, S(2) is bonded in a 6-coordinate geometry to one Rb(1), one Rb(4), two equivalent Rb(3), one Nb(2), and one Cu(2) atom. In the third S site, S(3) is bonded in a 3-coordinate geometry to one Rb(1), two equivalent Rb(3), one Mg(1), one Nb(2), and one Cu(2) atom. In the fourth S site, S(4) is bonded in a 6-coordinate geometry to one Rb(2), one Rb(3), two equivalent Rb(4), one Nb(2), and one Cu(2) atom. In the fifth S site, S(5) is bonded in a 6-coordinate geometry to one Rb(1), one Rb(4), two equivalent Rb(2), one Nb(1), and one Cu(1) atom. In the sixth S site, S(6) is bonded in a 6-coordinate geometry to one Rb(2), two equivalent Rb(1), one Mg(1), one Nb(1), and one Cu(1) atom. In the seventh S site, S(7) is bonded in a 4-coordinate geometry to two equivalent Rb(1), one Mg(1), one Nb(1), and one Cu(1) atom. In the eighth S site, S(8) is bonded in a 6-coordinate geometry to one Rb(1), one Rb(4), two equivalent Rb(2), one Nb(1), and one Cu(1) atom. is represented by the CIF card [CIF]
data_Rb4MgNb2(CuS4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.642
_cell_length_b   7.715
_cell_length_c   12.424
_cell_angle_alpha   83.607
_cell_angle_beta   79.217
_cell_angle_gamma   66.762
_symmetry_Int_Tables_number   1
_cell_volume   487.683
_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
  Rb  Rb0  1  0.816  0.695  0.386  1.0
  Rb  Rb1  1  0.444  0.736  0.100  1.0
  Rb  Rb2  1  0.130  0.265  0.644  1.0
  Rb  Rb3  1  0.529  0.259  0.907  1.0
  Mg  Mg4  1  0.734  0.158  0.458  1.0
  Nb  Nb5  1  0.399  0.221  0.254  1.0
  Nb  Nb6  1  0.604  0.760  0.745  1.0
  Cu  Cu7  1  0.896  0.241  0.233  1.0
  Cu  Cu8  1  0.109  0.751  0.750  1.0
  S  S9  1  0.218  0.939  0.853  1.0
  S  S10  1  0.505  0.571  0.642  1.0
  S  S11  1  0.782  0.963  0.633  1.0
  S  S12  1  0.902  0.565  0.856  1.0
  S  S13  1  0.094  0.438  0.148  1.0
  S  S14  1  0.495  0.434  0.350  1.0
  S  S15  1  0.185  0.036  0.363  1.0
  S  S16  1  0.776  0.047  0.142  1.0
[/CIF]
.
The structure described by Rb4MgNb2(CuS4)2 crystallizes in the triclinic P1 space group. There are four inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 9-coordinate geometry to one Mg(1), one S(2), one S(3), one S(5), one S(8), two equivalent S(6), and two equivalent S(7) atoms. In the second Rb site, Rb(2) is bonded in a 7-coordinate geometry to one S(1), one S(4), one S(6), two equivalent S(5), and two equivalent S(8) atoms. In the third Rb site, Rb(3) is bonded in a 6-coordinate geometry to one S(1), one S(4), two equivalent S(2), and two equivalent S(3) atoms. In the fourth Rb site, Rb(4) is bonded in a 7-coordinate geometry to one S(2), one S(5), one S(8), two equivalent S(1), and two equivalent S(4) atoms. Mg(1) is bonded in a 3-coordinate geometry to one Rb(1), one S(3), one S(6), and one S(7) atom. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one S(5), one S(6), one S(7), and one S(8) atom to form NbS4 tetrahedra that share edges with two equivalent Cu(1)S4 tetrahedra. In the second Nb site, Nb(2) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form NbS4 tetrahedra that share edges with two equivalent Cu(2)S4 tetrahedra. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(5), one S(6), one S(7), and one S(8) atom to form distorted CuS4 tetrahedra that share edges with two equivalent Nb(1)S4 tetrahedra. In the second Cu site, Cu(2) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form distorted CuS4 tetrahedra that share 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 6-coordinate geometry to one Rb(2), one Rb(3), two equivalent Rb(4), one Nb(2), and one Cu(2) atom. In the second S site, S(2) is bonded in a 6-coordinate geometry to one Rb(1), one Rb(4), two equivalent Rb(3), one Nb(2), and one Cu(2) atom. In the third S site, S(3) is bonded in a 3-coordinate geometry to one Rb(1), two equivalent Rb(3), one Mg(1), one Nb(2), and one Cu(2) atom. In the fourth S site, S(4) is bonded in a 6-coordinate geometry to one Rb(2), one Rb(3), two equivalent Rb(4), one Nb(2), and one Cu(2) atom. In the fifth S site, S(5) is bonded in a 6-coordinate geometry to one Rb(1), one Rb(4), two equivalent Rb(2), one Nb(1), and one Cu(1) atom. In the sixth S site, S(6) is bonded in a 6-coordinate geometry to one Rb(2), two equivalent Rb(1), one Mg(1), one Nb(1), and one Cu(1) atom. In the seventh S site, S(7) is bonded in a 4-coordinate geometry to two equivalent Rb(1), one Mg(1), one Nb(1), and one Cu(1) atom. In the eighth S site, S(8) is bonded in a 6-coordinate geometry to one Rb(1), one Rb(4), two equivalent Rb(2), one Nb(1), and one Cu(1) atom. is represented by the CIF card [CIF]
data_Rb4MgNb2(CuS4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.642
_cell_length_b   7.715
_cell_length_c   12.424
_cell_angle_alpha   83.607
_cell_angle_beta   79.217
_cell_angle_gamma   66.762
_symmetry_Int_Tables_number   1
_cell_volume   487.683
_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
  Rb  Rb0  1  0.816  0.695  0.386  1.0
  Rb  Rb1  1  0.444  0.736  0.100  1.0
  Rb  Rb2  1  0.130  0.265  0.644  1.0
  Rb  Rb3  1  0.529  0.259  0.907  1.0
  Mg  Mg4  1  0.734  0.158  0.458  1.0
  Nb  Nb5  1  0.399  0.221  0.254  1.0
  Nb  Nb6  1  0.604  0.760  0.745  1.0
  Cu  Cu7  1  0.896  0.241  0.233  1.0
  Cu  Cu8  1  0.109  0.751  0.750  1.0
  S  S9  1  0.218  0.939  0.853  1.0
  S  S10  1  0.505  0.571  0.642  1.0
  S  S11  1  0.782  0.963  0.633  1.0
  S  S12  1  0.902  0.565  0.856  1.0
  S  S13  1  0.094  0.438  0.148  1.0
  S  S14  1  0.495  0.434  0.350  1.0
  S  S15  1  0.185  0.036  0.363  1.0
  S  S16  1  0.776  0.047  0.142  1.0
[/CIF]
.