The material structure described by Cu5Si2S7 is Enargite-like structured and crystallizes in the monoclinic Cc space group. There are five inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(3), one S(4), one S(5), and one S(7) atom to form CuS4 tetrahedra that share  a cornercorner with one Cu(2)S4 tetrahedra,  a cornercorner with one Cu(3)S4 tetrahedra, corners with two equivalent Cu(5)S4 tetrahedra, corners with two equivalent Si(2)S4 tetrahedra, corners with three equivalent Cu(4)S4 tetrahedra, and corners with three equivalent Si(1)S4 tetrahedra. In the second Cu site, Cu(2) is bonded to one S(1), one S(2), one S(6), and one S(7) atom to form CuS4 tetrahedra that share  a cornercorner with one Cu(1)S4 tetrahedra,  a cornercorner with one Cu(4)S4 tetrahedra, corners with two equivalent Si(1)S4 tetrahedra, corners with two equivalent Si(2)S4 tetrahedra, corners with three equivalent Cu(3)S4 tetrahedra, and corners with three equivalent Cu(5)S4 tetrahedra. In the third Cu site, Cu(3) is bonded to one S(1), one S(2), one S(4), and one S(6) atom to form CuS4 tetrahedra that share  a cornercorner with one Cu(1)S4 tetrahedra,  a cornercorner with one Si(1)S4 tetrahedra, corners with two equivalent Cu(4)S4 tetrahedra, corners with two equivalent Cu(5)S4 tetrahedra, corners with three equivalent Cu(2)S4 tetrahedra, and corners with three equivalent Si(2)S4 tetrahedra. In the fourth Cu site, Cu(4) is bonded to one S(3), one S(4), one S(5), and one S(6) atom to form CuS4 tetrahedra that share  a cornercorner with one Cu(2)S4 tetrahedra,  a cornercorner with one Cu(5)S4 tetrahedra, corners with two equivalent Cu(3)S4 tetrahedra, corners with two equivalent Si(1)S4 tetrahedra, corners with three equivalent Cu(1)S4 tetrahedra, and corners with three equivalent Si(2)S4 tetrahedra. In the fifth Cu site, Cu(5) is bonded to one S(1), one S(2), one S(3), and one S(7) atom to form CuS4 tetrahedra that share  a cornercorner with one Cu(4)S4 tetrahedra,  a cornercorner with one Si(2)S4 tetrahedra, corners with two equivalent Cu(1)S4 tetrahedra, corners with two equivalent Cu(3)S4 tetrahedra, corners with three equivalent Cu(2)S4 tetrahedra, and corners with three equivalent Si(1)S4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one S(1), one S(3), one S(5), and one S(7) atom to form SiS4 tetrahedra that share  a cornercorner with one Cu(3)S4 tetrahedra,  a cornercorner with one Si(2)S4 tetrahedra, corners with two equivalent Cu(2)S4 tetrahedra, corners with two equivalent Cu(4)S4 tetrahedra, corners with three equivalent Cu(1)S4 tetrahedra, and corners with three equivalent Cu(5)S4 tetrahedra. In the second Si site, Si(2) is bonded to one S(2), one S(4), one S(5), and one S(6) atom to form SiS4 tetrahedra that share  a cornercorner with one Cu(5)S4 tetrahedra,  a cornercorner with one Si(1)S4 tetrahedra, corners with two equivalent Cu(1)S4 tetrahedra, corners with two equivalent Cu(2)S4 tetrahedra, corners with three equivalent Cu(3)S4 tetrahedra, and corners with three equivalent Cu(4)S4 tetrahedra. There are seven inequivalent S sites. In the first S site, S(3) is bonded to one Cu(1), one Cu(4), one Cu(5), and one Si(1) atom to form SCu3Si tetrahedra that share  a cornercorner with one S(2)Cu3Si tetrahedra,  a cornercorner with one S(6)Cu3Si tetrahedra, corners with two equivalent S(1)Cu3Si tetrahedra, corners with two equivalent S(4)Cu3Si tetrahedra, corners with three equivalent S(5)Cu2Si2 tetrahedra, and corners with three equivalent S(7)Cu3Si tetrahedra. In the second S site, S(4) is bonded to one Cu(1), one Cu(3), one Cu(4), and one Si(2) atom to form SCu3Si tetrahedra that share  a cornercorner with one S(1)Cu3Si tetrahedra,  a cornercorner with one S(7)Cu3Si tetrahedra, corners with two equivalent S(2)Cu3Si tetrahedra, corners with two equivalent S(3)Cu3Si tetrahedra, corners with three equivalent S(5)Cu2Si2 tetrahedra, and corners with three equivalent S(6)Cu3Si tetrahedra. In the third S site, S(5) is bonded to one Cu(1), one Cu(4), one Si(1), and one Si(2) atom to form corner-sharing SCu2Si2 tetrahedra. In the fourth S site, S(6) is bonded to one Cu(2), one Cu(3), one Cu(4), and one Si(2) atom to form SCu3Si tetrahedra that share  a cornercorner with one S(3)Cu3Si tetrahedra,  a cornercorner with one S(7)Cu3Si tetrahedra, corners with two equivalent S(5)Cu2Si2 tetrahedra, corners with two equivalent S(1)Cu3Si tetrahedra, corners with three equivalent S(2)Cu3Si tetrahedra, and corners with three equivalent S(4)Cu3Si tetrahedra. In the fifth S site, S(7) is bonded to one Cu(1), one Cu(2), one Cu(5), and one Si(1) atom to form SCu3Si tetrahedra that share  a cornercorner with one S(4)Cu3Si tetrahedra,  a cornercorner with one S(6)Cu3Si tetrahedra, corners with two equivalent S(5)Cu2Si2 tetrahedra, corners with two equivalent S(2)Cu3Si tetrahedra, corners with three equivalent S(1)Cu3Si tetrahedra, and corners with three equivalent S(3)Cu3Si tetrahedra. In the sixth S site, S(1) is bonded to one Cu(2), one Cu(3), one Cu(5), and one Si(1) atom to form SCu3Si tetrahedra that share  a cornercorner with one S(5)Cu2Si2 tetrahedra,  a cornercorner with one S(4)Cu3Si tetrahedra, corners with two equivalent S(3)Cu3Si tetrahedra, corners with two equivalent S(6)Cu3Si tetrahedra, corners with three equivalent S(2)Cu3Si tetrahedra, and corners with three equivalent S(7)Cu3Si tetrahedra. In the seventh S site, S(2) is bonded to one Cu(2), one Cu(3), one Cu(5), and one Si(2) atom to form SCu3Si tetrahedra that share  a cornercorner with one S(5)Cu2Si2 tetrahedra,  a cornercorner with one S(3)Cu3Si tetrahedra, corners with two equivalent S(4)Cu3Si tetrahedra, corners with two equivalent S(7)Cu3Si tetrahedra, corners with three equivalent S(1)Cu3Si tetrahedra, and corners with three equivalent S(6)Cu3Si tetrahedra. is represented by the CIF card [CIF]
data_Cu5Si2S7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.704
_cell_length_b   8.704
_cell_length_c   9.546
_cell_angle_alpha   87.937
_cell_angle_beta   87.937
_cell_angle_gamma   42.441
_symmetry_Int_Tables_number   1
_cell_volume   487.668
_cell_formula_units_Z   2
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
  Cu  Cu0  1  0.785  0.456  0.299  1.0
  Cu  Cu1  1  0.456  0.785  0.799  1.0
  Cu  Cu2  1  0.482  0.190  0.727  1.0
  Cu  Cu3  1  0.190  0.482  0.227  1.0
  Cu  Cu4  1  0.079  0.734  0.875  1.0
  Cu  Cu5  1  0.734  0.079  0.375  1.0
  Cu  Cu6  1  0.228  0.874  0.163  1.0
  Cu  Cu7  1  0.874  0.228  0.663  1.0
  Cu  Cu8  1  0.941  0.593  0.580  1.0
  Cu  Cu9  1  0.593  0.941  0.080  1.0
  Si  Si10  1  0.367  0.025  0.435  1.0
  Si  Si11  1  0.025  0.367  0.935  1.0
  Si  Si12  1  0.645  0.315  0.003  1.0
  Si  Si13  1  0.315  0.645  0.503  1.0
  S  S14  1  0.970  0.623  0.029  1.0
  S  S15  1  0.623  0.970  0.529  1.0
  S  S16  1  0.564  0.204  0.161  1.0
  S  S17  1  0.204  0.564  0.661  1.0
  S  S18  1  0.834  0.495  0.749  1.0
  S  S19  1  0.495  0.834  0.249  1.0
  S  S20  1  0.671  0.361  0.462  1.0
  S  S21  1  0.361  0.671  0.962  1.0
  S  S22  1  0.257  0.919  0.590  1.0
  S  S23  1  0.919  0.257  0.090  1.0
  S  S24  1  0.113  0.776  0.321  1.0
  S  S25  1  0.776  0.113  0.821  1.0
  S  S26  1  0.377  0.079  0.886  1.0
  S  S27  1  0.079  0.377  0.386  1.0
[/CIF]
.
The material structure described by Cu5Si2S7 is Enargite-like structured and crystallizes in the monoclinic Cc space group. There are five inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(3), one S(4), one S(5), and one S(7) atom to form CuS4 tetrahedra that share  a cornercorner with one Cu(2)S4 tetrahedra,  a cornercorner with one Cu(3)S4 tetrahedra, corners with two equivalent Cu(5)S4 tetrahedra, corners with two equivalent Si(2)S4 tetrahedra, corners with three equivalent Cu(4)S4 tetrahedra, and corners with three equivalent Si(1)S4 tetrahedra. In the second Cu site, Cu(2) is bonded to one S(1), one S(2), one S(6), and one S(7) atom to form CuS4 tetrahedra that share  a cornercorner with one Cu(1)S4 tetrahedra,  a cornercorner with one Cu(4)S4 tetrahedra, corners with two equivalent Si(1)S4 tetrahedra, corners with two equivalent Si(2)S4 tetrahedra, corners with three equivalent Cu(3)S4 tetrahedra, and corners with three equivalent Cu(5)S4 tetrahedra. In the third Cu site, Cu(3) is bonded to one S(1), one S(2), one S(4), and one S(6) atom to form CuS4 tetrahedra that share  a cornercorner with one Cu(1)S4 tetrahedra,  a cornercorner with one Si(1)S4 tetrahedra, corners with two equivalent Cu(4)S4 tetrahedra, corners with two equivalent Cu(5)S4 tetrahedra, corners with three equivalent Cu(2)S4 tetrahedra, and corners with three equivalent Si(2)S4 tetrahedra. In the fourth Cu site, Cu(4) is bonded to one S(3), one S(4), one S(5), and one S(6) atom to form CuS4 tetrahedra that share  a cornercorner with one Cu(2)S4 tetrahedra,  a cornercorner with one Cu(5)S4 tetrahedra, corners with two equivalent Cu(3)S4 tetrahedra, corners with two equivalent Si(1)S4 tetrahedra, corners with three equivalent Cu(1)S4 tetrahedra, and corners with three equivalent Si(2)S4 tetrahedra. In the fifth Cu site, Cu(5) is bonded to one S(1), one S(2), one S(3), and one S(7) atom to form CuS4 tetrahedra that share  a cornercorner with one Cu(4)S4 tetrahedra,  a cornercorner with one Si(2)S4 tetrahedra, corners with two equivalent Cu(1)S4 tetrahedra, corners with two equivalent Cu(3)S4 tetrahedra, corners with three equivalent Cu(2)S4 tetrahedra, and corners with three equivalent Si(1)S4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one S(1), one S(3), one S(5), and one S(7) atom to form SiS4 tetrahedra that share  a cornercorner with one Cu(3)S4 tetrahedra,  a cornercorner with one Si(2)S4 tetrahedra, corners with two equivalent Cu(2)S4 tetrahedra, corners with two equivalent Cu(4)S4 tetrahedra, corners with three equivalent Cu(1)S4 tetrahedra, and corners with three equivalent Cu(5)S4 tetrahedra. In the second Si site, Si(2) is bonded to one S(2), one S(4), one S(5), and one S(6) atom to form SiS4 tetrahedra that share  a cornercorner with one Cu(5)S4 tetrahedra,  a cornercorner with one Si(1)S4 tetrahedra, corners with two equivalent Cu(1)S4 tetrahedra, corners with two equivalent Cu(2)S4 tetrahedra, corners with three equivalent Cu(3)S4 tetrahedra, and corners with three equivalent Cu(4)S4 tetrahedra. There are seven inequivalent S sites. In the first S site, S(3) is bonded to one Cu(1), one Cu(4), one Cu(5), and one Si(1) atom to form SCu3Si tetrahedra that share  a cornercorner with one S(2)Cu3Si tetrahedra,  a cornercorner with one S(6)Cu3Si tetrahedra, corners with two equivalent S(1)Cu3Si tetrahedra, corners with two equivalent S(4)Cu3Si tetrahedra, corners with three equivalent S(5)Cu2Si2 tetrahedra, and corners with three equivalent S(7)Cu3Si tetrahedra. In the second S site, S(4) is bonded to one Cu(1), one Cu(3), one Cu(4), and one Si(2) atom to form SCu3Si tetrahedra that share  a cornercorner with one S(1)Cu3Si tetrahedra,  a cornercorner with one S(7)Cu3Si tetrahedra, corners with two equivalent S(2)Cu3Si tetrahedra, corners with two equivalent S(3)Cu3Si tetrahedra, corners with three equivalent S(5)Cu2Si2 tetrahedra, and corners with three equivalent S(6)Cu3Si tetrahedra. In the third S site, S(5) is bonded to one Cu(1), one Cu(4), one Si(1), and one Si(2) atom to form corner-sharing SCu2Si2 tetrahedra. In the fourth S site, S(6) is bonded to one Cu(2), one Cu(3), one Cu(4), and one Si(2) atom to form SCu3Si tetrahedra that share  a cornercorner with one S(3)Cu3Si tetrahedra,  a cornercorner with one S(7)Cu3Si tetrahedra, corners with two equivalent S(5)Cu2Si2 tetrahedra, corners with two equivalent S(1)Cu3Si tetrahedra, corners with three equivalent S(2)Cu3Si tetrahedra, and corners with three equivalent S(4)Cu3Si tetrahedra. In the fifth S site, S(7) is bonded to one Cu(1), one Cu(2), one Cu(5), and one Si(1) atom to form SCu3Si tetrahedra that share  a cornercorner with one S(4)Cu3Si tetrahedra,  a cornercorner with one S(6)Cu3Si tetrahedra, corners with two equivalent S(5)Cu2Si2 tetrahedra, corners with two equivalent S(2)Cu3Si tetrahedra, corners with three equivalent S(1)Cu3Si tetrahedra, and corners with three equivalent S(3)Cu3Si tetrahedra. In the sixth S site, S(1) is bonded to one Cu(2), one Cu(3), one Cu(5), and one Si(1) atom to form SCu3Si tetrahedra that share  a cornercorner with one S(5)Cu2Si2 tetrahedra,  a cornercorner with one S(4)Cu3Si tetrahedra, corners with two equivalent S(3)Cu3Si tetrahedra, corners with two equivalent S(6)Cu3Si tetrahedra, corners with three equivalent S(2)Cu3Si tetrahedra, and corners with three equivalent S(7)Cu3Si tetrahedra. In the seventh S site, S(2) is bonded to one Cu(2), one Cu(3), one Cu(5), and one Si(2) atom to form SCu3Si tetrahedra that share  a cornercorner with one S(5)Cu2Si2 tetrahedra,  a cornercorner with one S(3)Cu3Si tetrahedra, corners with two equivalent S(4)Cu3Si tetrahedra, corners with two equivalent S(7)Cu3Si tetrahedra, corners with three equivalent S(1)Cu3Si tetrahedra, and corners with three equivalent S(6)Cu3Si tetrahedra. is represented by the CIF card [CIF]
data_Cu5Si2S7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.704
_cell_length_b   8.704
_cell_length_c   9.546
_cell_angle_alpha   87.937
_cell_angle_beta   87.937
_cell_angle_gamma   42.441
_symmetry_Int_Tables_number   1
_cell_volume   487.668
_cell_formula_units_Z   2
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
  Cu  Cu0  1  0.785  0.456  0.299  1.0
  Cu  Cu1  1  0.456  0.785  0.799  1.0
  Cu  Cu2  1  0.482  0.190  0.727  1.0
  Cu  Cu3  1  0.190  0.482  0.227  1.0
  Cu  Cu4  1  0.079  0.734  0.875  1.0
  Cu  Cu5  1  0.734  0.079  0.375  1.0
  Cu  Cu6  1  0.228  0.874  0.163  1.0
  Cu  Cu7  1  0.874  0.228  0.663  1.0
  Cu  Cu8  1  0.941  0.593  0.580  1.0
  Cu  Cu9  1  0.593  0.941  0.080  1.0
  Si  Si10  1  0.367  0.025  0.435  1.0
  Si  Si11  1  0.025  0.367  0.935  1.0
  Si  Si12  1  0.645  0.315  0.003  1.0
  Si  Si13  1  0.315  0.645  0.503  1.0
  S  S14  1  0.970  0.623  0.029  1.0
  S  S15  1  0.623  0.970  0.529  1.0
  S  S16  1  0.564  0.204  0.161  1.0
  S  S17  1  0.204  0.564  0.661  1.0
  S  S18  1  0.834  0.495  0.749  1.0
  S  S19  1  0.495  0.834  0.249  1.0
  S  S20  1  0.671  0.361  0.462  1.0
  S  S21  1  0.361  0.671  0.962  1.0
  S  S22  1  0.257  0.919  0.590  1.0
  S  S23  1  0.919  0.257  0.090  1.0
  S  S24  1  0.113  0.776  0.321  1.0
  S  S25  1  0.776  0.113  0.821  1.0
  S  S26  1  0.377  0.079  0.886  1.0
  S  S27  1  0.079  0.377  0.386  1.0
[/CIF]
.