The compound described by Cr3CuAl2S8 is Spinel-derived structured and crystallizes in the trigonal R3m space group. Cr(1) is bonded to one S(2), one S(4), two equivalent S(1), and two equivalent S(3) atoms to form CrS6 octahedra that share corners with three equivalent Cu(1)S4 tetrahedra, corners with three equivalent Al(2)S4 tetrahedra, edges with two equivalent Al(1)S6 octahedra, and edges with four equivalent Cr(1)S6 octahedra. Cu(1) is bonded to one S(4) and three equivalent S(3) atoms to form CuS4 tetrahedra that share corners with three equivalent Al(1)S6 octahedra and corners with nine equivalent Cr(1)S6 octahedra. The corner-sharing octahedral tilt angles are 56°. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to three equivalent S(1) and three equivalent S(3) atoms to form AlS6 octahedra that share corners with three equivalent Cu(1)S4 tetrahedra, corners with three equivalent Al(2)S4 tetrahedra, and edges with six equivalent Cr(1)S6 octahedra. In the second Al site, Al(2) is bonded to one S(2) and three equivalent S(1) atoms to form AlS4 tetrahedra that share corners with three equivalent Al(1)S6 octahedra and corners with nine equivalent Cr(1)S6 octahedra. The corner-sharing octahedral tilt angles are 59°. There are four inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Cr(1), one Al(1), and one Al(2) atom to form distorted SAl2Cr2 trigonal pyramids that share  a cornercorner with one S(2)AlCr3 trigonal pyramid, corners with two equivalent S(1)Al2Cr2 trigonal pyramids,  an edgeedge with one S(2)AlCr3 trigonal pyramid, and edges with two equivalent S(1)Al2Cr2 trigonal pyramids. In the second S site, S(2) is bonded to three equivalent Cr(1) and one Al(2) atom to form a mixture of distorted corner and edge-sharing SAlCr3 trigonal pyramids. In the third S site, S(3) is bonded in a rectangular see-saw-like geometry to two equivalent Cr(1), one Cu(1), and one Al(1) atom. In the fourth S site, S(4) is bonded in a rectangular see-saw-like geometry to three equivalent Cr(1) and one Cu(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Al2Cr3CuS8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.050
_cell_length_b   7.050
_cell_length_c   7.050
_cell_angle_alpha   60.046
_cell_angle_beta   60.046
_cell_angle_gamma   60.046
_symmetry_Int_Tables_number   1
_cell_volume   248.056
_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
  Al  Al0  1  0.005  0.005  0.005  1.0
  Al  Al1  1  0.625  0.625  0.625  1.0
  Cr  Cr2  1  0.489  0.004  0.004  1.0
  Cr  Cr3  1  0.004  0.004  0.489  1.0
  Cr  Cr4  1  0.004  0.489  0.004  1.0
  Cu  Cu5  1  0.375  0.375  0.375  1.0
  S  S6  1  0.225  0.758  0.758  1.0
  S  S7  1  0.758  0.758  0.225  1.0
  S  S8  1  0.758  0.225  0.758  1.0
  S  S9  1  0.758  0.758  0.758  1.0
  S  S10  1  0.774  0.242  0.242  1.0
  S  S11  1  0.242  0.242  0.774  1.0
  S  S12  1  0.242  0.774  0.242  1.0
  S  S13  1  0.241  0.241  0.241  1.0
[/CIF]
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The compound described by Cr3CuAl2S8 is Spinel-derived structured and crystallizes in the trigonal R3m space group. Cr(1) is bonded to one S(2), one S(4), two equivalent S(1), and two equivalent S(3) atoms to form CrS6 octahedra that share corners with three equivalent Cu(1)S4 tetrahedra, corners with three equivalent Al(2)S4 tetrahedra, edges with two equivalent Al(1)S6 octahedra, and edges with four equivalent Cr(1)S6 octahedra. Cu(1) is bonded to one S(4) and three equivalent S(3) atoms to form CuS4 tetrahedra that share corners with three equivalent Al(1)S6 octahedra and corners with nine equivalent Cr(1)S6 octahedra. The corner-sharing octahedral tilt angles are 56°. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to three equivalent S(1) and three equivalent S(3) atoms to form AlS6 octahedra that share corners with three equivalent Cu(1)S4 tetrahedra, corners with three equivalent Al(2)S4 tetrahedra, and edges with six equivalent Cr(1)S6 octahedra. In the second Al site, Al(2) is bonded to one S(2) and three equivalent S(1) atoms to form AlS4 tetrahedra that share corners with three equivalent Al(1)S6 octahedra and corners with nine equivalent Cr(1)S6 octahedra. The corner-sharing octahedral tilt angles are 59°. There are four inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Cr(1), one Al(1), and one Al(2) atom to form distorted SAl2Cr2 trigonal pyramids that share  a cornercorner with one S(2)AlCr3 trigonal pyramid, corners with two equivalent S(1)Al2Cr2 trigonal pyramids,  an edgeedge with one S(2)AlCr3 trigonal pyramid, and edges with two equivalent S(1)Al2Cr2 trigonal pyramids. In the second S site, S(2) is bonded to three equivalent Cr(1) and one Al(2) atom to form a mixture of distorted corner and edge-sharing SAlCr3 trigonal pyramids. In the third S site, S(3) is bonded in a rectangular see-saw-like geometry to two equivalent Cr(1), one Cu(1), and one Al(1) atom. In the fourth S site, S(4) is bonded in a rectangular see-saw-like geometry to three equivalent Cr(1) and one Cu(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Al2Cr3CuS8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.050
_cell_length_b   7.050
_cell_length_c   7.050
_cell_angle_alpha   60.046
_cell_angle_beta   60.046
_cell_angle_gamma   60.046
_symmetry_Int_Tables_number   1
_cell_volume   248.056
_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
  Al  Al0  1  0.005  0.005  0.005  1.0
  Al  Al1  1  0.625  0.625  0.625  1.0
  Cr  Cr2  1  0.489  0.004  0.004  1.0
  Cr  Cr3  1  0.004  0.004  0.489  1.0
  Cr  Cr4  1  0.004  0.489  0.004  1.0
  Cu  Cu5  1  0.375  0.375  0.375  1.0
  S  S6  1  0.225  0.758  0.758  1.0
  S  S7  1  0.758  0.758  0.225  1.0
  S  S8  1  0.758  0.225  0.758  1.0
  S  S9  1  0.758  0.758  0.758  1.0
  S  S10  1  0.774  0.242  0.242  1.0
  S  S11  1  0.242  0.242  0.774  1.0
  S  S12  1  0.242  0.774  0.242  1.0
  S  S13  1  0.241  0.241  0.241  1.0
[/CIF]
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