The crystal structure described by Cr8NiCu3S16 is Spinel-derived structured and crystallizes in the trigonal R3m space group. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to three equivalent S(3) and three equivalent S(7) atoms to form CrS6 octahedra that share corners with three equivalent Ni(1)S4 tetrahedra, corners with three equivalent Cu(2)S4 tetrahedra, edges with three equivalent Cr(3)S6 octahedra, and edges with three equivalent Cr(4)S6 octahedra. In the second Cr site, Cr(2) is bonded to three equivalent S(4) and three equivalent S(8) atoms to form CrS6 octahedra that share corners with three equivalent Cu(1)S4 tetrahedra, corners with three equivalent Cu(3)S4 tetrahedra, edges with three equivalent Cr(3)S6 octahedra, and edges with three equivalent Cr(4)S6 octahedra. In the third Cr site, Cr(3) is bonded to one S(1), one S(6), two equivalent S(4), and two equivalent S(7) atoms to form CrS6 octahedra that share  a cornercorner with one Ni(1)S4 tetrahedra,  a cornercorner with one Cu(3)S4 tetrahedra, corners with two equivalent Cu(1)S4 tetrahedra, corners with two equivalent Cu(2)S4 tetrahedra,  an edgeedge with one Cr(1)S6 octahedra,  an edgeedge with one Cr(2)S6 octahedra, and edges with four equivalent Cr(3)S6 octahedra. In the fourth Cr site, Cr(4) is bonded to one S(2), one S(5), two equivalent S(3), and two equivalent S(8) atoms to form CrS6 octahedra that share  a cornercorner with one Cu(1)S4 tetrahedra,  a cornercorner with one Cu(2)S4 tetrahedra, corners with two equivalent Ni(1)S4 tetrahedra, corners with two equivalent Cu(3)S4 tetrahedra,  an edgeedge with one Cr(1)S6 octahedra,  an edgeedge with one Cr(2)S6 octahedra, and edges with four equivalent Cr(4)S6 octahedra. Ni(1) is bonded to one S(1) and three equivalent S(3) atoms to form NiS4 tetrahedra that share corners with three equivalent Cr(1)S6 octahedra, corners with three equivalent Cr(3)S6 octahedra, and corners with six equivalent Cr(4)S6 octahedra. The corner-sharing octahedral tilt angles are 57°. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(2) and three equivalent S(4) atoms to form CuS4 tetrahedra that share corners with three equivalent Cr(2)S6 octahedra, corners with three equivalent Cr(4)S6 octahedra, and corners with six equivalent Cr(3)S6 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. In the second Cu site, Cu(2) is bonded to one S(5) and three equivalent S(7) atoms to form CuS4 tetrahedra that share corners with three equivalent Cr(1)S6 octahedra, corners with three equivalent Cr(4)S6 octahedra, and corners with six equivalent Cr(3)S6 octahedra. The corner-sharing octahedral tilt angles are 57°. In the third Cu site, Cu(3) is bonded to one S(6) and three equivalent S(8) atoms to form CuS4 tetrahedra that share corners with three equivalent Cr(2)S6 octahedra, corners with three equivalent Cr(3)S6 octahedra, and corners with six equivalent Cr(4)S6 octahedra. The corner-sharing octahedral tilt angles are 57°. There are eight inequivalent S sites. In the first S site, S(1) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Cr(3) and one Ni(1) atom. In the second S site, S(2) is bonded to three equivalent Cr(4) and one Cu(1) atom to form distorted corner-sharing SCr3Cu trigonal pyramids. In the third S site, S(3) is bonded in a distorted rectangular see-saw-like geometry to one Cr(1), two equivalent Cr(4), and one Ni(1) atom. In the fourth S site, S(4) is bonded to one Cr(2), two equivalent Cr(3), and one Cu(1) atom to form a mixture of distorted corner and edge-sharing SCr3Cu trigonal pyramids. In the fifth S site, S(5) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Cr(4) and one Cu(2) atom. In the sixth S site, S(6) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Cr(3) and one Cu(3) atom. In the seventh S site, S(7) is bonded in a distorted rectangular see-saw-like geometry to one Cr(1), two equivalent Cr(3), and one Cu(2) atom. In the eighth S site, S(8) is bonded in a distorted rectangular see-saw-like geometry to one Cr(2), two equivalent Cr(4), and one Cu(3) atom. is represented by the CIF file [CIF]
data_Cr8Cu3NiS16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.043
_cell_length_b   12.043
_cell_length_c   12.043
_cell_angle_alpha   33.521
_cell_angle_beta   33.521
_cell_angle_gamma   33.521
_symmetry_Int_Tables_number   1
_cell_volume   474.500
_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
  Cr  Cr0  1  0.250  0.250  0.250  1.0
  Cr  Cr1  1  0.750  0.750  0.750  1.0
  Cr  Cr2  1  0.001  0.001  0.499  1.0
  Cr  Cr3  1  0.501  0.501  0.998  1.0
  Cr  Cr4  1  0.001  0.499  0.001  1.0
  Cr  Cr5  1  0.501  0.998  0.501  1.0
  Cr  Cr6  1  0.998  0.501  0.501  1.0
  Cr  Cr7  1  0.499  0.001  0.001  1.0
  Cu  Cu8  1  0.438  0.438  0.438  1.0
  Cu  Cu9  1  0.562  0.562  0.562  1.0
  Cu  Cu10  1  0.063  0.063  0.063  1.0
  Ni  Ni11  1  0.937  0.937  0.937  1.0
  S  S12  1  0.872  0.872  0.872  1.0
  S  S13  1  0.371  0.371  0.371  1.0
  S  S14  1  0.134  0.134  0.610  1.0
  S  S15  1  0.636  0.636  0.107  1.0
  S  S16  1  0.134  0.610  0.134  1.0
  S  S17  1  0.636  0.107  0.636  1.0
  S  S18  1  0.610  0.134  0.134  1.0
  S  S19  1  0.107  0.636  0.636  1.0
  S  S20  1  0.629  0.629  0.629  1.0
  S  S21  1  0.129  0.129  0.129  1.0
  S  S22  1  0.364  0.364  0.894  1.0
  S  S23  1  0.864  0.864  0.393  1.0
  S  S24  1  0.364  0.894  0.364  1.0
  S  S25  1  0.864  0.393  0.864  1.0
  S  S26  1  0.894  0.364  0.364  1.0
  S  S27  1  0.393  0.864  0.864  1.0
[/CIF]
.
The crystal structure described by Cr8NiCu3S16 is Spinel-derived structured and crystallizes in the trigonal R3m space group. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to three equivalent S(3) and three equivalent S(7) atoms to form CrS6 octahedra that share corners with three equivalent Ni(1)S4 tetrahedra, corners with three equivalent Cu(2)S4 tetrahedra, edges with three equivalent Cr(3)S6 octahedra, and edges with three equivalent Cr(4)S6 octahedra. In the second Cr site, Cr(2) is bonded to three equivalent S(4) and three equivalent S(8) atoms to form CrS6 octahedra that share corners with three equivalent Cu(1)S4 tetrahedra, corners with three equivalent Cu(3)S4 tetrahedra, edges with three equivalent Cr(3)S6 octahedra, and edges with three equivalent Cr(4)S6 octahedra. In the third Cr site, Cr(3) is bonded to one S(1), one S(6), two equivalent S(4), and two equivalent S(7) atoms to form CrS6 octahedra that share  a cornercorner with one Ni(1)S4 tetrahedra,  a cornercorner with one Cu(3)S4 tetrahedra, corners with two equivalent Cu(1)S4 tetrahedra, corners with two equivalent Cu(2)S4 tetrahedra,  an edgeedge with one Cr(1)S6 octahedra,  an edgeedge with one Cr(2)S6 octahedra, and edges with four equivalent Cr(3)S6 octahedra. In the fourth Cr site, Cr(4) is bonded to one S(2), one S(5), two equivalent S(3), and two equivalent S(8) atoms to form CrS6 octahedra that share  a cornercorner with one Cu(1)S4 tetrahedra,  a cornercorner with one Cu(2)S4 tetrahedra, corners with two equivalent Ni(1)S4 tetrahedra, corners with two equivalent Cu(3)S4 tetrahedra,  an edgeedge with one Cr(1)S6 octahedra,  an edgeedge with one Cr(2)S6 octahedra, and edges with four equivalent Cr(4)S6 octahedra. Ni(1) is bonded to one S(1) and three equivalent S(3) atoms to form NiS4 tetrahedra that share corners with three equivalent Cr(1)S6 octahedra, corners with three equivalent Cr(3)S6 octahedra, and corners with six equivalent Cr(4)S6 octahedra. The corner-sharing octahedral tilt angles are 57°. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(2) and three equivalent S(4) atoms to form CuS4 tetrahedra that share corners with three equivalent Cr(2)S6 octahedra, corners with three equivalent Cr(4)S6 octahedra, and corners with six equivalent Cr(3)S6 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. In the second Cu site, Cu(2) is bonded to one S(5) and three equivalent S(7) atoms to form CuS4 tetrahedra that share corners with three equivalent Cr(1)S6 octahedra, corners with three equivalent Cr(4)S6 octahedra, and corners with six equivalent Cr(3)S6 octahedra. The corner-sharing octahedral tilt angles are 57°. In the third Cu site, Cu(3) is bonded to one S(6) and three equivalent S(8) atoms to form CuS4 tetrahedra that share corners with three equivalent Cr(2)S6 octahedra, corners with three equivalent Cr(3)S6 octahedra, and corners with six equivalent Cr(4)S6 octahedra. The corner-sharing octahedral tilt angles are 57°. There are eight inequivalent S sites. In the first S site, S(1) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Cr(3) and one Ni(1) atom. In the second S site, S(2) is bonded to three equivalent Cr(4) and one Cu(1) atom to form distorted corner-sharing SCr3Cu trigonal pyramids. In the third S site, S(3) is bonded in a distorted rectangular see-saw-like geometry to one Cr(1), two equivalent Cr(4), and one Ni(1) atom. In the fourth S site, S(4) is bonded to one Cr(2), two equivalent Cr(3), and one Cu(1) atom to form a mixture of distorted corner and edge-sharing SCr3Cu trigonal pyramids. In the fifth S site, S(5) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Cr(4) and one Cu(2) atom. In the sixth S site, S(6) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Cr(3) and one Cu(3) atom. In the seventh S site, S(7) is bonded in a distorted rectangular see-saw-like geometry to one Cr(1), two equivalent Cr(3), and one Cu(2) atom. In the eighth S site, S(8) is bonded in a distorted rectangular see-saw-like geometry to one Cr(2), two equivalent Cr(4), and one Cu(3) atom. is represented by the CIF file [CIF]
data_Cr8Cu3NiS16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.043
_cell_length_b   12.043
_cell_length_c   12.043
_cell_angle_alpha   33.521
_cell_angle_beta   33.521
_cell_angle_gamma   33.521
_symmetry_Int_Tables_number   1
_cell_volume   474.500
_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
  Cr  Cr0  1  0.250  0.250  0.250  1.0
  Cr  Cr1  1  0.750  0.750  0.750  1.0
  Cr  Cr2  1  0.001  0.001  0.499  1.0
  Cr  Cr3  1  0.501  0.501  0.998  1.0
  Cr  Cr4  1  0.001  0.499  0.001  1.0
  Cr  Cr5  1  0.501  0.998  0.501  1.0
  Cr  Cr6  1  0.998  0.501  0.501  1.0
  Cr  Cr7  1  0.499  0.001  0.001  1.0
  Cu  Cu8  1  0.438  0.438  0.438  1.0
  Cu  Cu9  1  0.562  0.562  0.562  1.0
  Cu  Cu10  1  0.063  0.063  0.063  1.0
  Ni  Ni11  1  0.937  0.937  0.937  1.0
  S  S12  1  0.872  0.872  0.872  1.0
  S  S13  1  0.371  0.371  0.371  1.0
  S  S14  1  0.134  0.134  0.610  1.0
  S  S15  1  0.636  0.636  0.107  1.0
  S  S16  1  0.134  0.610  0.134  1.0
  S  S17  1  0.636  0.107  0.636  1.0
  S  S18  1  0.610  0.134  0.134  1.0
  S  S19  1  0.107  0.636  0.636  1.0
  S  S20  1  0.629  0.629  0.629  1.0
  S  S21  1  0.129  0.129  0.129  1.0
  S  S22  1  0.364  0.364  0.894  1.0
  S  S23  1  0.864  0.864  0.393  1.0
  S  S24  1  0.364  0.894  0.364  1.0
  S  S25  1  0.864  0.393  0.864  1.0
  S  S26  1  0.894  0.364  0.364  1.0
  S  S27  1  0.393  0.864  0.864  1.0
[/CIF]
.