The crystal structure described by Mg(CuS)2 crystallizes in the trigonal R3m space group. Mg(1) is bonded to one S(2) and three equivalent S(1) atoms to form distorted MgS4 tetrahedra that share corners with four equivalent Cu(1)S4 tetrahedra, corners with six equivalent Mg(1)S4 tetrahedra, and edges with three equivalent Cu(1)S4 tetrahedra. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(2) and three equivalent S(1) atoms to form CuS4 tetrahedra that share corners with four equivalent Mg(1)S4 tetrahedra, corners with six equivalent Cu(1)S4 tetrahedra, and edges with three equivalent Mg(1)S4 tetrahedra. In the second Cu site, Cu(2) is bonded in a trigonal planar geometry to three equivalent S(2) atoms. There are two inequivalent S sites. In the first S site, S(1) is bonded to three equivalent Mg(1) and three equivalent Cu(1) atoms to form distorted SMg3Cu3 octahedra that share corners with six equivalent S(2)MgCu4 trigonal bipyramids and edges with six equivalent S(1)Mg3Cu3 octahedra. In the second S site, S(2) is bonded to one Mg(1), one Cu(1), and three equivalent Cu(2) atoms to form SMgCu4 trigonal bipyramids that share corners with six equivalent S(1)Mg3Cu3 octahedra and corners with six equivalent S(2)MgCu4 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 62-67°. is represented by the CIF file [CIF]
data_Mg(CuS)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.883
_cell_length_b   3.883
_cell_length_c   7.147
_cell_angle_alpha   105.777
_cell_angle_beta   105.777
_cell_angle_gamma   59.922
_symmetry_Int_Tables_number   1
_cell_volume   88.538
_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
  Mg  Mg0  1  0.622  0.622  0.867  1.0
  Cu  Cu1  1  0.392  0.392  0.177  1.0
  Cu  Cu2  1  0.843  0.843  0.529  1.0
  S  S3  1  0.013  0.013  0.039  1.0
  S  S4  1  0.504  0.504  0.513  1.0
[/CIF]
.
The crystal structure described by Mg(CuS)2 crystallizes in the trigonal R3m space group. Mg(1) is bonded to one S(2) and three equivalent S(1) atoms to form distorted MgS4 tetrahedra that share corners with four equivalent Cu(1)S4 tetrahedra, corners with six equivalent Mg(1)S4 tetrahedra, and edges with three equivalent Cu(1)S4 tetrahedra. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(2) and three equivalent S(1) atoms to form CuS4 tetrahedra that share corners with four equivalent Mg(1)S4 tetrahedra, corners with six equivalent Cu(1)S4 tetrahedra, and edges with three equivalent Mg(1)S4 tetrahedra. In the second Cu site, Cu(2) is bonded in a trigonal planar geometry to three equivalent S(2) atoms. There are two inequivalent S sites. In the first S site, S(1) is bonded to three equivalent Mg(1) and three equivalent Cu(1) atoms to form distorted SMg3Cu3 octahedra that share corners with six equivalent S(2)MgCu4 trigonal bipyramids and edges with six equivalent S(1)Mg3Cu3 octahedra. In the second S site, S(2) is bonded to one Mg(1), one Cu(1), and three equivalent Cu(2) atoms to form SMgCu4 trigonal bipyramids that share corners with six equivalent S(1)Mg3Cu3 octahedra and corners with six equivalent S(2)MgCu4 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 62-67°. is represented by the CIF file [CIF]
data_Mg(CuS)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.883
_cell_length_b   3.883
_cell_length_c   7.147
_cell_angle_alpha   105.777
_cell_angle_beta   105.777
_cell_angle_gamma   59.922
_symmetry_Int_Tables_number   1
_cell_volume   88.538
_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
  Mg  Mg0  1  0.622  0.622  0.867  1.0
  Cu  Cu1  1  0.392  0.392  0.177  1.0
  Cu  Cu2  1  0.843  0.843  0.529  1.0
  S  S3  1  0.013  0.013  0.039  1.0
  S  S4  1  0.504  0.504  0.513  1.0
[/CIF]
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