The structure described by Cr10Co4CuSe20 crystallizes in the monoclinic C2/m space group. There are five inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one Se(1), one Se(6), two equivalent Se(3), and two equivalent Se(8) atoms to form distorted CrSe6 octahedra that share corners with two equivalent Co(2)Se6 octahedra, corners with four equivalent Co(1)Se6 octahedra, edges with two equivalent Cr(1)Se6 octahedra, edges with four equivalent Cr(3)Se6 octahedra, and  a faceface with one Co(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 49-53°. In the second Cr site, Cr(2) is bonded to three equivalent Se(2) and three equivalent Se(7) atoms to form distorted CrSe6 octahedra that share corners with six equivalent Co(2)Se6 octahedra, edges with six equivalent Cr(2)Se6 octahedra, and  a faceface with one Co(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 49-53°. In the third Cr site, Cr(3) is bonded to one Se(3), one Se(8), two equivalent Se(1), and two equivalent Se(6) atoms to form distorted CrSe6 octahedra that share corners with two equivalent Co(1)Se6 octahedra, corners with four equivalent Co(2)Se6 octahedra, edges with two equivalent Cr(3)Se6 octahedra, edges with four equivalent Cr(1)Se6 octahedra, and  a faceface with one Co(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 49-53°. In the fourth Cr site, Cr(4) is bonded to one Se(4), one Se(9), two equivalent Se(10), and two equivalent Se(5) atoms to form distorted CrSe6 octahedra that share corners with two equivalent Cu(1)Se6 octahedra, corners with four equivalent Co(1)Se6 octahedra, edges with two equivalent Cr(4)Se6 octahedra, edges with four equivalent Cr(5)Se6 octahedra, and  a faceface with one Cu(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 50-53°. In the fifth Cr site, Cr(5) is bonded to one Se(10), one Se(5), two equivalent Se(4), and two equivalent Se(9) atoms to form distorted CrSe6 octahedra that share corners with two equivalent Co(1)Se6 octahedra, corners with four equivalent Cu(1)Se6 octahedra, edges with two equivalent Cr(5)Se6 octahedra, edges with four equivalent Cr(4)Se6 octahedra, and  a faceface with one Co(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 48-52°. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one Se(3), one Se(5), two equivalent Se(6), and two equivalent Se(9) atoms to form CoSe6 octahedra that share corners with two equivalent Cr(3)Se6 octahedra, corners with two equivalent Cr(5)Se6 octahedra, corners with four equivalent Cr(1)Se6 octahedra, corners with four equivalent Cr(4)Se6 octahedra, edges with two equivalent Co(1)Se6 octahedra,  a faceface with one Cr(3)Se6 octahedra, and  a faceface with one Cr(5)Se6 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. In the second Co site, Co(2) is bonded to one Se(1), one Se(2), two equivalent Se(7), and two equivalent Se(8) atoms to form CoSe6 octahedra that share corners with two equivalent Cr(1)Se6 octahedra, corners with four equivalent Cr(3)Se6 octahedra, corners with six equivalent Cr(2)Se6 octahedra, edges with two equivalent Co(2)Se6 octahedra,  a faceface with one Cr(1)Se6 octahedra, and  a faceface with one Cr(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 49-53°. Cu(1) is bonded to two equivalent Se(4) and four equivalent Se(10) atoms to form CuSe6 octahedra that share corners with four equivalent Cr(4)Se6 octahedra, corners with eight equivalent Cr(5)Se6 octahedra, edges with two equivalent Cu(1)Se6 octahedra, and faces with two equivalent Cr(4)Se6 octahedra. The corner-sharing octahedral tilt angles range from 50-52°. There are ten inequivalent Se sites. In the first Se site, Se(3) is bonded in a rectangular see-saw-like geometry to one Cr(3), two equivalent Cr(1), and one Co(1) atom. In the second Se site, Se(4) is bonded in a rectangular see-saw-like geometry to one Cr(4), two equivalent Cr(5), and one Cu(1) atom. In the third Se site, Se(5) is bonded in a rectangular see-saw-like geometry to one Cr(5), two equivalent Cr(4), and one Co(1) atom. In the fourth Se site, Se(6) is bonded to one Cr(1), two equivalent Cr(3), and two equivalent Co(1) atoms to form a mixture of distorted edge and corner-sharing SeCr3Co2 square pyramids. In the fifth Se site, Se(7) is bonded to three equivalent Cr(2) and two equivalent Co(2) atoms to form a mixture of distorted edge and corner-sharing SeCr3Co2 square pyramids. In the sixth Se site, Se(8) is bonded to one Cr(3), two equivalent Cr(1), and two equivalent Co(2) atoms to form a mixture of distorted edge and corner-sharing SeCr3Co2 square pyramids. In the seventh Se site, Se(9) is bonded to one Cr(4), two equivalent Cr(5), and two equivalent Co(1) atoms to form a mixture of distorted edge and corner-sharing SeCr3Co2 square pyramids. In the eighth Se site, Se(10) is bonded in a 5-coordinate geometry to one Cr(5), two equivalent Cr(4), and two equivalent Cu(1) atoms. In the ninth Se site, Se(1) is bonded in a rectangular see-saw-like geometry to one Cr(1), two equivalent Cr(3), and one Co(2) atom. In the tenth Se site, Se(2) is bonded in a rectangular see-saw-like geometry to three equivalent Cr(2) and one Co(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cr10Co4CuSe20
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   27.980
_cell_length_b   27.980
_cell_length_c   6.365
_cell_angle_alpha   84.899
_cell_angle_beta   84.899
_cell_angle_gamma   7.508
_symmetry_Int_Tables_number   1
_cell_volume   648.492
_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  0.352  0.352  0.626  1.0
  Cr  Cr1  1  0.752  0.752  0.226  1.0
  Cr  Cr2  1  0.152  0.152  0.827  1.0
  Cr  Cr3  1  0.552  0.552  0.428  1.0
  Cr  Cr4  1  0.951  0.951  0.027  1.0
  Cr  Cr5  1  0.848  0.848  0.173  1.0
  Cr  Cr6  1  0.248  0.248  0.774  1.0
  Cr  Cr7  1  0.648  0.648  0.374  1.0
  Cr  Cr8  1  0.049  0.049  0.973  1.0
  Cr  Cr9  1  0.448  0.448  0.572  1.0
  Co  Co10  1  0.900  0.900  0.101  1.0
  Co  Co11  1  0.300  0.300  0.700  1.0
  Co  Co12  1  0.700  0.700  0.300  1.0
  Co  Co13  1  0.100  0.100  0.899  1.0
  Cu  Cu14  1  0.500  0.500  0.500  1.0
  Se  Se15  1  0.323  0.323  0.348  1.0
  Se  Se16  1  0.723  0.723  0.948  1.0
  Se  Se17  1  0.123  0.123  0.549  1.0
  Se  Se18  1  0.524  0.524  0.141  1.0
  Se  Se19  1  0.923  0.923  0.749  1.0
  Se  Se20  1  0.877  0.877  0.451  1.0
  Se  Se21  1  0.277  0.277  0.052  1.0
  Se  Se22  1  0.677  0.677  0.652  1.0
  Se  Se23  1  0.077  0.077  0.251  1.0
  Se  Se24  1  0.476  0.476  0.859  1.0
  Se  Se25  1  0.374  0.374  0.971  1.0
  Se  Se26  1  0.774  0.774  0.570  1.0
  Se  Se27  1  0.174  0.174  0.171  1.0
  Se  Se28  1  0.575  0.575  0.771  1.0
  Se  Se29  1  0.972  0.972  0.366  1.0
  Se  Se30  1  0.826  0.826  0.829  1.0
  Se  Se31  1  0.226  0.226  0.430  1.0
  Se  Se32  1  0.626  0.626  0.029  1.0
  Se  Se33  1  0.028  0.028  0.634  1.0
  Se  Se34  1  0.425  0.425  0.229  1.0
[/CIF]
.
The structure described by Cr10Co4CuSe20 crystallizes in the monoclinic C2/m space group. There are five inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one Se(1), one Se(6), two equivalent Se(3), and two equivalent Se(8) atoms to form distorted CrSe6 octahedra that share corners with two equivalent Co(2)Se6 octahedra, corners with four equivalent Co(1)Se6 octahedra, edges with two equivalent Cr(1)Se6 octahedra, edges with four equivalent Cr(3)Se6 octahedra, and  a faceface with one Co(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 49-53°. In the second Cr site, Cr(2) is bonded to three equivalent Se(2) and three equivalent Se(7) atoms to form distorted CrSe6 octahedra that share corners with six equivalent Co(2)Se6 octahedra, edges with six equivalent Cr(2)Se6 octahedra, and  a faceface with one Co(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 49-53°. In the third Cr site, Cr(3) is bonded to one Se(3), one Se(8), two equivalent Se(1), and two equivalent Se(6) atoms to form distorted CrSe6 octahedra that share corners with two equivalent Co(1)Se6 octahedra, corners with four equivalent Co(2)Se6 octahedra, edges with two equivalent Cr(3)Se6 octahedra, edges with four equivalent Cr(1)Se6 octahedra, and  a faceface with one Co(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 49-53°. In the fourth Cr site, Cr(4) is bonded to one Se(4), one Se(9), two equivalent Se(10), and two equivalent Se(5) atoms to form distorted CrSe6 octahedra that share corners with two equivalent Cu(1)Se6 octahedra, corners with four equivalent Co(1)Se6 octahedra, edges with two equivalent Cr(4)Se6 octahedra, edges with four equivalent Cr(5)Se6 octahedra, and  a faceface with one Cu(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 50-53°. In the fifth Cr site, Cr(5) is bonded to one Se(10), one Se(5), two equivalent Se(4), and two equivalent Se(9) atoms to form distorted CrSe6 octahedra that share corners with two equivalent Co(1)Se6 octahedra, corners with four equivalent Cu(1)Se6 octahedra, edges with two equivalent Cr(5)Se6 octahedra, edges with four equivalent Cr(4)Se6 octahedra, and  a faceface with one Co(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 48-52°. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one Se(3), one Se(5), two equivalent Se(6), and two equivalent Se(9) atoms to form CoSe6 octahedra that share corners with two equivalent Cr(3)Se6 octahedra, corners with two equivalent Cr(5)Se6 octahedra, corners with four equivalent Cr(1)Se6 octahedra, corners with four equivalent Cr(4)Se6 octahedra, edges with two equivalent Co(1)Se6 octahedra,  a faceface with one Cr(3)Se6 octahedra, and  a faceface with one Cr(5)Se6 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. In the second Co site, Co(2) is bonded to one Se(1), one Se(2), two equivalent Se(7), and two equivalent Se(8) atoms to form CoSe6 octahedra that share corners with two equivalent Cr(1)Se6 octahedra, corners with four equivalent Cr(3)Se6 octahedra, corners with six equivalent Cr(2)Se6 octahedra, edges with two equivalent Co(2)Se6 octahedra,  a faceface with one Cr(1)Se6 octahedra, and  a faceface with one Cr(2)Se6 octahedra. The corner-sharing octahedral tilt angles range from 49-53°. Cu(1) is bonded to two equivalent Se(4) and four equivalent Se(10) atoms to form CuSe6 octahedra that share corners with four equivalent Cr(4)Se6 octahedra, corners with eight equivalent Cr(5)Se6 octahedra, edges with two equivalent Cu(1)Se6 octahedra, and faces with two equivalent Cr(4)Se6 octahedra. The corner-sharing octahedral tilt angles range from 50-52°. There are ten inequivalent Se sites. In the first Se site, Se(3) is bonded in a rectangular see-saw-like geometry to one Cr(3), two equivalent Cr(1), and one Co(1) atom. In the second Se site, Se(4) is bonded in a rectangular see-saw-like geometry to one Cr(4), two equivalent Cr(5), and one Cu(1) atom. In the third Se site, Se(5) is bonded in a rectangular see-saw-like geometry to one Cr(5), two equivalent Cr(4), and one Co(1) atom. In the fourth Se site, Se(6) is bonded to one Cr(1), two equivalent Cr(3), and two equivalent Co(1) atoms to form a mixture of distorted edge and corner-sharing SeCr3Co2 square pyramids. In the fifth Se site, Se(7) is bonded to three equivalent Cr(2) and two equivalent Co(2) atoms to form a mixture of distorted edge and corner-sharing SeCr3Co2 square pyramids. In the sixth Se site, Se(8) is bonded to one Cr(3), two equivalent Cr(1), and two equivalent Co(2) atoms to form a mixture of distorted edge and corner-sharing SeCr3Co2 square pyramids. In the seventh Se site, Se(9) is bonded to one Cr(4), two equivalent Cr(5), and two equivalent Co(1) atoms to form a mixture of distorted edge and corner-sharing SeCr3Co2 square pyramids. In the eighth Se site, Se(10) is bonded in a 5-coordinate geometry to one Cr(5), two equivalent Cr(4), and two equivalent Cu(1) atoms. In the ninth Se site, Se(1) is bonded in a rectangular see-saw-like geometry to one Cr(1), two equivalent Cr(3), and one Co(2) atom. In the tenth Se site, Se(2) is bonded in a rectangular see-saw-like geometry to three equivalent Cr(2) and one Co(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cr10Co4CuSe20
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   27.980
_cell_length_b   27.980
_cell_length_c   6.365
_cell_angle_alpha   84.899
_cell_angle_beta   84.899
_cell_angle_gamma   7.508
_symmetry_Int_Tables_number   1
_cell_volume   648.492
_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  0.352  0.352  0.626  1.0
  Cr  Cr1  1  0.752  0.752  0.226  1.0
  Cr  Cr2  1  0.152  0.152  0.827  1.0
  Cr  Cr3  1  0.552  0.552  0.428  1.0
  Cr  Cr4  1  0.951  0.951  0.027  1.0
  Cr  Cr5  1  0.848  0.848  0.173  1.0
  Cr  Cr6  1  0.248  0.248  0.774  1.0
  Cr  Cr7  1  0.648  0.648  0.374  1.0
  Cr  Cr8  1  0.049  0.049  0.973  1.0
  Cr  Cr9  1  0.448  0.448  0.572  1.0
  Co  Co10  1  0.900  0.900  0.101  1.0
  Co  Co11  1  0.300  0.300  0.700  1.0
  Co  Co12  1  0.700  0.700  0.300  1.0
  Co  Co13  1  0.100  0.100  0.899  1.0
  Cu  Cu14  1  0.500  0.500  0.500  1.0
  Se  Se15  1  0.323  0.323  0.348  1.0
  Se  Se16  1  0.723  0.723  0.948  1.0
  Se  Se17  1  0.123  0.123  0.549  1.0
  Se  Se18  1  0.524  0.524  0.141  1.0
  Se  Se19  1  0.923  0.923  0.749  1.0
  Se  Se20  1  0.877  0.877  0.451  1.0
  Se  Se21  1  0.277  0.277  0.052  1.0
  Se  Se22  1  0.677  0.677  0.652  1.0
  Se  Se23  1  0.077  0.077  0.251  1.0
  Se  Se24  1  0.476  0.476  0.859  1.0
  Se  Se25  1  0.374  0.374  0.971  1.0
  Se  Se26  1  0.774  0.774  0.570  1.0
  Se  Se27  1  0.174  0.174  0.171  1.0
  Se  Se28  1  0.575  0.575  0.771  1.0
  Se  Se29  1  0.972  0.972  0.366  1.0
  Se  Se30  1  0.826  0.826  0.829  1.0
  Se  Se31  1  0.226  0.226  0.430  1.0
  Se  Se32  1  0.626  0.626  0.029  1.0
  Se  Se33  1  0.028  0.028  0.634  1.0
  Se  Se34  1  0.425  0.425  0.229  1.0
[/CIF]
.