The material structure described by Cu7As6Se13 crystallizes in the trigonal R3 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(5) atom to form corner-sharing CuSe4 tetrahedra. In the second Cu site, Cu(2) is bonded to one Se(1), one Se(4), and two equivalent Se(3) atoms to form corner-sharing CuSe4 tetrahedra. In the third Cu site, Cu(3) is bonded in a rectangular see-saw-like geometry to one Se(5) and three equivalent Se(4) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 4-coordinate geometry to one Se(2), one Se(4), and two equivalent Se(1) atoms. In the second As site, As(2) is bonded in a trigonal non-coplanar geometry to one Se(2), one Se(3), and one Se(4) atom. There are five inequivalent Se sites. In the first Se site, Se(1) is bonded to one Cu(1), one Cu(2), and two equivalent As(1) atoms to form distorted SeCu2As2 tetrahedra that share corners with two equivalent Se(1)Cu2As2 tetrahedra, corners with three equivalent Se(3)Cu3As tetrahedra, and corners with three equivalent Se(4)Cu2As2 trigonal pyramids. In the second Se site, Se(2) is bonded in a trigonal non-coplanar geometry to one Cu(1), one As(1), and one As(2) atom. In the third Se site, Se(3) is bonded to one Cu(1), two equivalent Cu(2), and one As(2) atom to form distorted SeCu3As tetrahedra that share corners with two equivalent Se(3)Cu3As tetrahedra, corners with three equivalent Se(1)Cu2As2 tetrahedra, and corners with three equivalent Se(4)Cu2As2 trigonal pyramids. In the fourth Se site, Se(4) is bonded to one Cu(2), one Cu(3), one As(1), and one As(2) atom to form distorted SeCu2As2 trigonal pyramids that share corners with three equivalent Se(1)Cu2As2 tetrahedra, corners with three equivalent Se(3)Cu3As tetrahedra, and corners with two equivalent Se(4)Cu2As2 trigonal pyramids. In the fifth Se site, Se(5) is bonded in a rectangular see-saw-like geometry to one Cu(3) and three equivalent Cu(1) atoms. is represented by the CIF file [CIF]
data_Cu7As6Se13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.767
_cell_length_b   8.767
_cell_length_c   8.767
_cell_angle_alpha   102.363
_cell_angle_beta   102.363
_cell_angle_gamma   102.363
_symmetry_Int_Tables_number   1
_cell_volume   618.603
_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
  Cu  Cu0  1  0.936  0.144  0.206  1.0
  Cu  Cu1  1  0.144  0.206  0.936  1.0
  Cu  Cu2  1  0.206  0.936  0.144  1.0
  Cu  Cu3  1  0.372  0.278  0.587  1.0
  Cu  Cu4  1  0.278  0.587  0.372  1.0
  Cu  Cu5  1  0.587  0.372  0.278  1.0
  Cu  Cu6  1  0.754  0.754  0.754  1.0
  As  As7  1  0.986  0.844  0.497  1.0
  As  As8  1  0.844  0.497  0.986  1.0
  As  As9  1  0.497  0.986  0.844  1.0
  As  As10  1  0.643  0.059  0.527  1.0
  As  As11  1  0.059  0.527  0.643  1.0
  As  As12  1  0.527  0.643  0.059  1.0
  Se  Se13  1  0.281  0.097  0.741  1.0
  Se  Se14  1  0.097  0.741  0.281  1.0
  Se  Se15  1  0.741  0.281  0.097  1.0
  Se  Se16  1  0.952  0.328  0.787  1.0
  Se  Se17  1  0.328  0.787  0.952  1.0
  Se  Se18  1  0.787  0.952  0.328  1.0
  Se  Se19  1  0.143  0.350  0.441  1.0
  Se  Se20  1  0.350  0.441  0.143  1.0
  Se  Se21  1  0.441  0.143  0.350  1.0
  Se  Se22  1  0.574  0.510  0.796  1.0
  Se  Se23  1  0.510  0.796  0.574  1.0
  Se  Se24  1  0.796  0.574  0.510  1.0
  Se  Se25  1  0.970  0.970  0.970  1.0
[/CIF]
.
The material structure described by Cu7As6Se13 crystallizes in the trigonal R3 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(5) atom to form corner-sharing CuSe4 tetrahedra. In the second Cu site, Cu(2) is bonded to one Se(1), one Se(4), and two equivalent Se(3) atoms to form corner-sharing CuSe4 tetrahedra. In the third Cu site, Cu(3) is bonded in a rectangular see-saw-like geometry to one Se(5) and three equivalent Se(4) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 4-coordinate geometry to one Se(2), one Se(4), and two equivalent Se(1) atoms. In the second As site, As(2) is bonded in a trigonal non-coplanar geometry to one Se(2), one Se(3), and one Se(4) atom. There are five inequivalent Se sites. In the first Se site, Se(1) is bonded to one Cu(1), one Cu(2), and two equivalent As(1) atoms to form distorted SeCu2As2 tetrahedra that share corners with two equivalent Se(1)Cu2As2 tetrahedra, corners with three equivalent Se(3)Cu3As tetrahedra, and corners with three equivalent Se(4)Cu2As2 trigonal pyramids. In the second Se site, Se(2) is bonded in a trigonal non-coplanar geometry to one Cu(1), one As(1), and one As(2) atom. In the third Se site, Se(3) is bonded to one Cu(1), two equivalent Cu(2), and one As(2) atom to form distorted SeCu3As tetrahedra that share corners with two equivalent Se(3)Cu3As tetrahedra, corners with three equivalent Se(1)Cu2As2 tetrahedra, and corners with three equivalent Se(4)Cu2As2 trigonal pyramids. In the fourth Se site, Se(4) is bonded to one Cu(2), one Cu(3), one As(1), and one As(2) atom to form distorted SeCu2As2 trigonal pyramids that share corners with three equivalent Se(1)Cu2As2 tetrahedra, corners with three equivalent Se(3)Cu3As tetrahedra, and corners with two equivalent Se(4)Cu2As2 trigonal pyramids. In the fifth Se site, Se(5) is bonded in a rectangular see-saw-like geometry to one Cu(3) and three equivalent Cu(1) atoms. is represented by the CIF file [CIF]
data_Cu7As6Se13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.767
_cell_length_b   8.767
_cell_length_c   8.767
_cell_angle_alpha   102.363
_cell_angle_beta   102.363
_cell_angle_gamma   102.363
_symmetry_Int_Tables_number   1
_cell_volume   618.603
_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
  Cu  Cu0  1  0.936  0.144  0.206  1.0
  Cu  Cu1  1  0.144  0.206  0.936  1.0
  Cu  Cu2  1  0.206  0.936  0.144  1.0
  Cu  Cu3  1  0.372  0.278  0.587  1.0
  Cu  Cu4  1  0.278  0.587  0.372  1.0
  Cu  Cu5  1  0.587  0.372  0.278  1.0
  Cu  Cu6  1  0.754  0.754  0.754  1.0
  As  As7  1  0.986  0.844  0.497  1.0
  As  As8  1  0.844  0.497  0.986  1.0
  As  As9  1  0.497  0.986  0.844  1.0
  As  As10  1  0.643  0.059  0.527  1.0
  As  As11  1  0.059  0.527  0.643  1.0
  As  As12  1  0.527  0.643  0.059  1.0
  Se  Se13  1  0.281  0.097  0.741  1.0
  Se  Se14  1  0.097  0.741  0.281  1.0
  Se  Se15  1  0.741  0.281  0.097  1.0
  Se  Se16  1  0.952  0.328  0.787  1.0
  Se  Se17  1  0.328  0.787  0.952  1.0
  Se  Se18  1  0.787  0.952  0.328  1.0
  Se  Se19  1  0.143  0.350  0.441  1.0
  Se  Se20  1  0.350  0.441  0.143  1.0
  Se  Se21  1  0.441  0.143  0.350  1.0
  Se  Se22  1  0.574  0.510  0.796  1.0
  Se  Se23  1  0.510  0.796  0.574  1.0
  Se  Se24  1  0.796  0.574  0.510  1.0
  Se  Se25  1  0.970  0.970  0.970  1.0
[/CIF]
.