The structure described by Cu9In11Se20 is Enargite-like structured and crystallizes in the tetragonal I-4 space group. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one Se(1), one Se(2), one Se(3), and one Se(4) atom to form CuSe4 tetrahedra that share  a cornercorner with one Cu(3)Se4 tetrahedra,  a cornercorner with one In(4)Se4 tetrahedra,  a cornercorner with one In(5)Se4 tetrahedra, corners with three equivalent Cu(2)Se4 tetrahedra, corners with three equivalent In(2)Se4 tetrahedra, and corners with three equivalent In(3)Se4 tetrahedra. In the second Cu site, Cu(2) is bonded to one Se(2), one Se(3), one Se(4), and one Se(5) atom to form CuSe4 tetrahedra that share  a cornercorner with one In(1)Se4 tetrahedra,  a cornercorner with one In(4)Se4 tetrahedra,  a cornercorner with one In(5)Se4 tetrahedra, corners with three equivalent Cu(1)Se4 tetrahedra, corners with three equivalent In(2)Se4 tetrahedra, and corners with three equivalent In(3)Se4 tetrahedra. In the third Cu site, Cu(3) is bonded to four equivalent Se(1) atoms to form CuSe4 tetrahedra that share corners with four equivalent Cu(1)Se4 tetrahedra, corners with four equivalent In(2)Se4 tetrahedra, and corners with four equivalent In(3)Se4 tetrahedra. There are five inequivalent In sites. In the first In site, In(1) is bonded to four equivalent Se(5) atoms to form InSe4 tetrahedra that share corners with four equivalent Cu(2)Se4 tetrahedra, corners with four equivalent In(2)Se4 tetrahedra, and corners with four equivalent In(3)Se4 tetrahedra. In the second In site, In(2) is bonded to one Se(1), one Se(2), one Se(3), and one Se(5) atom to form InSe4 tetrahedra that share  a cornercorner with one Cu(3)Se4 tetrahedra,  a cornercorner with one In(1)Se4 tetrahedra,  a cornercorner with one In(4)Se4 tetrahedra, corners with three equivalent Cu(1)Se4 tetrahedra, corners with three equivalent Cu(2)Se4 tetrahedra, and corners with three equivalent In(3)Se4 tetrahedra. In the third In site, In(3) is bonded to one Se(1), one Se(3), one Se(4), and one Se(5) atom to form InSe4 tetrahedra that share  a cornercorner with one Cu(3)Se4 tetrahedra,  a cornercorner with one In(1)Se4 tetrahedra,  a cornercorner with one In(5)Se4 tetrahedra, corners with three equivalent Cu(1)Se4 tetrahedra, corners with three equivalent Cu(2)Se4 tetrahedra, and corners with three equivalent In(2)Se4 tetrahedra. In the fourth In site, In(4) is bonded to four equivalent Se(2) atoms to form InSe4 tetrahedra that share corners with four equivalent Cu(1)Se4 tetrahedra, corners with four equivalent Cu(2)Se4 tetrahedra, and corners with four equivalent In(2)Se4 tetrahedra. In the fifth In site, In(5) is bonded to four equivalent Se(4) atoms to form InSe4 tetrahedra that share corners with four equivalent Cu(1)Se4 tetrahedra, corners with four equivalent Cu(2)Se4 tetrahedra, and corners with four equivalent In(3)Se4 tetrahedra. There are five inequivalent Se sites. In the first Se site, Se(1) is bonded to one Cu(1), one Cu(3), one In(2), and one In(3) atom to form SeIn2Cu2 tetrahedra that share corners with two equivalent Se(2)In2Cu2 tetrahedra, corners with two equivalent Se(4)In2Cu2 tetrahedra, corners with two equivalent Se(5)In3Cu tetrahedra, corners with three equivalent Se(1)In2Cu2 tetrahedra, and corners with three equivalent Se(3)In2Cu2 tetrahedra. In the second Se site, Se(2) is bonded to one Cu(1), one Cu(2), one In(2), and one In(4) atom to form SeIn2Cu2 tetrahedra that share corners with two equivalent Se(1)In2Cu2 tetrahedra, corners with two equivalent Se(4)In2Cu2 tetrahedra, corners with two equivalent Se(5)In3Cu tetrahedra, corners with three equivalent Se(2)In2Cu2 tetrahedra, and corners with three equivalent Se(3)In2Cu2 tetrahedra. In the third Se site, Se(3) is bonded to one Cu(1), one Cu(2), one In(2), and one In(3) atom to form SeIn2Cu2 tetrahedra that share corners with three equivalent Se(1)In2Cu2 tetrahedra, corners with three equivalent Se(2)In2Cu2 tetrahedra, corners with three equivalent Se(4)In2Cu2 tetrahedra, and corners with three equivalent Se(5)In3Cu tetrahedra. In the fourth Se site, Se(4) is bonded to one Cu(1), one Cu(2), one In(3), and one In(5) atom to form SeIn2Cu2 tetrahedra that share corners with two equivalent Se(1)In2Cu2 tetrahedra, corners with two equivalent Se(2)In2Cu2 tetrahedra, corners with two equivalent Se(5)In3Cu tetrahedra, corners with three equivalent Se(3)In2Cu2 tetrahedra, and corners with three equivalent Se(4)In2Cu2 tetrahedra. In the fifth Se site, Se(5) is bonded to one Cu(2), one In(1), one In(2), and one In(3) atom to form SeIn3Cu tetrahedra that share corners with two equivalent Se(1)In2Cu2 tetrahedra, corners with two equivalent Se(2)In2Cu2 tetrahedra, corners with two equivalent Se(4)In2Cu2 tetrahedra, corners with three equivalent Se(3)In2Cu2 tetrahedra, and corners with three equivalent Se(5)In3Cu tetrahedra. is represented by the CIF card [CIF]
data_In11Cu9Se20
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.120
_cell_length_b   11.120
_cell_length_c   11.120
_cell_angle_alpha   106.855
_cell_angle_beta   106.855
_cell_angle_gamma   114.842
_symmetry_Int_Tables_number   1
_cell_volume   1051.463
_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
  In  In0  1  0.500  0.500  0.000  1.0
  In  In1  1  0.595  0.187  0.793  1.0
  In  In2  1  0.041  0.348  0.903  1.0
  In  In3  1  0.813  0.606  0.408  1.0
  In  In4  1  0.250  0.750  0.500  1.0
  In  In5  1  0.000  0.000  0.000  1.0
  In  In6  1  0.445  0.138  0.097  1.0
  In  In7  1  0.198  0.405  0.592  1.0
  In  In8  1  0.652  0.555  0.693  1.0
  In  In9  1  0.394  0.802  0.207  1.0
  In  In10  1  0.862  0.959  0.307  1.0
  Cu  Cu11  1  0.700  0.900  0.601  1.0
  Cu  Cu12  1  0.901  0.300  0.200  1.0
  Cu  Cu13  1  0.100  0.700  0.800  1.0
  Cu  Cu14  1  0.148  0.040  0.697  1.0
  Cu  Cu15  1  0.300  0.099  0.399  1.0
  Cu  Cu16  1  0.343  0.451  0.303  1.0
  Cu  Cu17  1  0.549  0.852  0.892  1.0
  Cu  Cu18  1  0.750  0.250  0.500  1.0
  Cu  Cu19  1  0.960  0.657  0.108  1.0
  Se  Se20  1  0.768  0.159  0.678  1.0
  Se  Se21  1  0.971  0.561  0.280  1.0
  Se  Se22  1  0.439  0.719  0.410  1.0
  Se  Se23  1  0.881  0.887  0.520  1.0
  Se  Se24  1  0.309  0.029  0.590  1.0
  Se  Se25  1  0.168  0.960  0.880  1.0
  Se  Se26  1  0.640  0.119  0.006  1.0
  Se  Se27  1  0.079  0.288  0.120  1.0
  Se  Se28  1  0.514  0.422  0.211  1.0
  Se  Se29  1  0.367  0.360  0.480  1.0
  Se  Se30  1  0.841  0.519  0.609  1.0
  Se  Se31  1  0.281  0.691  0.720  1.0
  Se  Se32  1  0.712  0.832  0.792  1.0
  Se  Se33  1  0.578  0.788  0.092  1.0
  Se  Se34  1  0.040  0.921  0.208  1.0
  Se  Se35  1  0.481  0.090  0.322  1.0
  Se  Se36  1  0.910  0.232  0.391  1.0
  Se  Se37  1  0.212  0.303  0.789  1.0
  Se  Se38  1  0.697  0.486  0.908  1.0
  Se  Se39  1  0.113  0.633  0.994  1.0
[/CIF]
.
The structure described by Cu9In11Se20 is Enargite-like structured and crystallizes in the tetragonal I-4 space group. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one Se(1), one Se(2), one Se(3), and one Se(4) atom to form CuSe4 tetrahedra that share  a cornercorner with one Cu(3)Se4 tetrahedra,  a cornercorner with one In(4)Se4 tetrahedra,  a cornercorner with one In(5)Se4 tetrahedra, corners with three equivalent Cu(2)Se4 tetrahedra, corners with three equivalent In(2)Se4 tetrahedra, and corners with three equivalent In(3)Se4 tetrahedra. In the second Cu site, Cu(2) is bonded to one Se(2), one Se(3), one Se(4), and one Se(5) atom to form CuSe4 tetrahedra that share  a cornercorner with one In(1)Se4 tetrahedra,  a cornercorner with one In(4)Se4 tetrahedra,  a cornercorner with one In(5)Se4 tetrahedra, corners with three equivalent Cu(1)Se4 tetrahedra, corners with three equivalent In(2)Se4 tetrahedra, and corners with three equivalent In(3)Se4 tetrahedra. In the third Cu site, Cu(3) is bonded to four equivalent Se(1) atoms to form CuSe4 tetrahedra that share corners with four equivalent Cu(1)Se4 tetrahedra, corners with four equivalent In(2)Se4 tetrahedra, and corners with four equivalent In(3)Se4 tetrahedra. There are five inequivalent In sites. In the first In site, In(1) is bonded to four equivalent Se(5) atoms to form InSe4 tetrahedra that share corners with four equivalent Cu(2)Se4 tetrahedra, corners with four equivalent In(2)Se4 tetrahedra, and corners with four equivalent In(3)Se4 tetrahedra. In the second In site, In(2) is bonded to one Se(1), one Se(2), one Se(3), and one Se(5) atom to form InSe4 tetrahedra that share  a cornercorner with one Cu(3)Se4 tetrahedra,  a cornercorner with one In(1)Se4 tetrahedra,  a cornercorner with one In(4)Se4 tetrahedra, corners with three equivalent Cu(1)Se4 tetrahedra, corners with three equivalent Cu(2)Se4 tetrahedra, and corners with three equivalent In(3)Se4 tetrahedra. In the third In site, In(3) is bonded to one Se(1), one Se(3), one Se(4), and one Se(5) atom to form InSe4 tetrahedra that share  a cornercorner with one Cu(3)Se4 tetrahedra,  a cornercorner with one In(1)Se4 tetrahedra,  a cornercorner with one In(5)Se4 tetrahedra, corners with three equivalent Cu(1)Se4 tetrahedra, corners with three equivalent Cu(2)Se4 tetrahedra, and corners with three equivalent In(2)Se4 tetrahedra. In the fourth In site, In(4) is bonded to four equivalent Se(2) atoms to form InSe4 tetrahedra that share corners with four equivalent Cu(1)Se4 tetrahedra, corners with four equivalent Cu(2)Se4 tetrahedra, and corners with four equivalent In(2)Se4 tetrahedra. In the fifth In site, In(5) is bonded to four equivalent Se(4) atoms to form InSe4 tetrahedra that share corners with four equivalent Cu(1)Se4 tetrahedra, corners with four equivalent Cu(2)Se4 tetrahedra, and corners with four equivalent In(3)Se4 tetrahedra. There are five inequivalent Se sites. In the first Se site, Se(1) is bonded to one Cu(1), one Cu(3), one In(2), and one In(3) atom to form SeIn2Cu2 tetrahedra that share corners with two equivalent Se(2)In2Cu2 tetrahedra, corners with two equivalent Se(4)In2Cu2 tetrahedra, corners with two equivalent Se(5)In3Cu tetrahedra, corners with three equivalent Se(1)In2Cu2 tetrahedra, and corners with three equivalent Se(3)In2Cu2 tetrahedra. In the second Se site, Se(2) is bonded to one Cu(1), one Cu(2), one In(2), and one In(4) atom to form SeIn2Cu2 tetrahedra that share corners with two equivalent Se(1)In2Cu2 tetrahedra, corners with two equivalent Se(4)In2Cu2 tetrahedra, corners with two equivalent Se(5)In3Cu tetrahedra, corners with three equivalent Se(2)In2Cu2 tetrahedra, and corners with three equivalent Se(3)In2Cu2 tetrahedra. In the third Se site, Se(3) is bonded to one Cu(1), one Cu(2), one In(2), and one In(3) atom to form SeIn2Cu2 tetrahedra that share corners with three equivalent Se(1)In2Cu2 tetrahedra, corners with three equivalent Se(2)In2Cu2 tetrahedra, corners with three equivalent Se(4)In2Cu2 tetrahedra, and corners with three equivalent Se(5)In3Cu tetrahedra. In the fourth Se site, Se(4) is bonded to one Cu(1), one Cu(2), one In(3), and one In(5) atom to form SeIn2Cu2 tetrahedra that share corners with two equivalent Se(1)In2Cu2 tetrahedra, corners with two equivalent Se(2)In2Cu2 tetrahedra, corners with two equivalent Se(5)In3Cu tetrahedra, corners with three equivalent Se(3)In2Cu2 tetrahedra, and corners with three equivalent Se(4)In2Cu2 tetrahedra. In the fifth Se site, Se(5) is bonded to one Cu(2), one In(1), one In(2), and one In(3) atom to form SeIn3Cu tetrahedra that share corners with two equivalent Se(1)In2Cu2 tetrahedra, corners with two equivalent Se(2)In2Cu2 tetrahedra, corners with two equivalent Se(4)In2Cu2 tetrahedra, corners with three equivalent Se(3)In2Cu2 tetrahedra, and corners with three equivalent Se(5)In3Cu tetrahedra. is represented by the CIF card [CIF]
data_In11Cu9Se20
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.120
_cell_length_b   11.120
_cell_length_c   11.120
_cell_angle_alpha   106.855
_cell_angle_beta   106.855
_cell_angle_gamma   114.842
_symmetry_Int_Tables_number   1
_cell_volume   1051.463
_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
  In  In0  1  0.500  0.500  0.000  1.0
  In  In1  1  0.595  0.187  0.793  1.0
  In  In2  1  0.041  0.348  0.903  1.0
  In  In3  1  0.813  0.606  0.408  1.0
  In  In4  1  0.250  0.750  0.500  1.0
  In  In5  1  0.000  0.000  0.000  1.0
  In  In6  1  0.445  0.138  0.097  1.0
  In  In7  1  0.198  0.405  0.592  1.0
  In  In8  1  0.652  0.555  0.693  1.0
  In  In9  1  0.394  0.802  0.207  1.0
  In  In10  1  0.862  0.959  0.307  1.0
  Cu  Cu11  1  0.700  0.900  0.601  1.0
  Cu  Cu12  1  0.901  0.300  0.200  1.0
  Cu  Cu13  1  0.100  0.700  0.800  1.0
  Cu  Cu14  1  0.148  0.040  0.697  1.0
  Cu  Cu15  1  0.300  0.099  0.399  1.0
  Cu  Cu16  1  0.343  0.451  0.303  1.0
  Cu  Cu17  1  0.549  0.852  0.892  1.0
  Cu  Cu18  1  0.750  0.250  0.500  1.0
  Cu  Cu19  1  0.960  0.657  0.108  1.0
  Se  Se20  1  0.768  0.159  0.678  1.0
  Se  Se21  1  0.971  0.561  0.280  1.0
  Se  Se22  1  0.439  0.719  0.410  1.0
  Se  Se23  1  0.881  0.887  0.520  1.0
  Se  Se24  1  0.309  0.029  0.590  1.0
  Se  Se25  1  0.168  0.960  0.880  1.0
  Se  Se26  1  0.640  0.119  0.006  1.0
  Se  Se27  1  0.079  0.288  0.120  1.0
  Se  Se28  1  0.514  0.422  0.211  1.0
  Se  Se29  1  0.367  0.360  0.480  1.0
  Se  Se30  1  0.841  0.519  0.609  1.0
  Se  Se31  1  0.281  0.691  0.720  1.0
  Se  Se32  1  0.712  0.832  0.792  1.0
  Se  Se33  1  0.578  0.788  0.092  1.0
  Se  Se34  1  0.040  0.921  0.208  1.0
  Se  Se35  1  0.481  0.090  0.322  1.0
  Se  Se36  1  0.910  0.232  0.391  1.0
  Se  Se37  1  0.212  0.303  0.789  1.0
  Se  Se38  1  0.697  0.486  0.908  1.0
  Se  Se39  1  0.113  0.633  0.994  1.0
[/CIF]
.