The compound described by Cu7Si2 crystallizes in the trigonal P-3m1 space group. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 11-coordinate geometry to one Cu(2), three equivalent Cu(3), three equivalent Cu(4), and four equivalent Si(1) atoms. In the second Cu site, Cu(2) is bonded in a 11-coordinate geometry to one Cu(1), three equivalent Cu(2), six equivalent Cu(3), and one Si(1) atom. In the third Cu site, Cu(3) is bonded in a 14-coordinate geometry to one Cu(3), one Cu(4), three equivalent Cu(1), six equivalent Cu(2), and three equivalent Si(1) atoms. In the fourth Cu site, Cu(4) is bonded in a 14-coordinate geometry to two equivalent Cu(3), six equivalent Cu(1), and six equivalent Si(1) atoms. Si(1) is bonded in a 11-coordinate geometry to one Cu(2), three equivalent Cu(3), three equivalent Cu(4), and four equivalent Cu(1) atoms. is represented by the CIF file [CIF]
data_Cu7Si2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.085
_cell_length_b   4.085
_cell_length_c   7.587
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   109.637
_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  0.333  0.667  0.155  1.0
  Cu  Cu1  1  0.667  0.333  0.845  1.0
  Cu  Cu2  1  0.333  0.667  0.496  1.0
  Cu  Cu3  1  0.667  0.333  0.504  1.0
  Cu  Cu4  1  0.000  0.000  0.330  1.0
  Cu  Cu5  1  0.000  0.000  0.670  1.0
  Cu  Cu6  1  0.000  0.000  0.000  1.0
  Si  Si7  1  0.333  0.667  0.809  1.0
  Si  Si8  1  0.667  0.333  0.191  1.0
[/CIF]
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The compound described by Cu7Si2 crystallizes in the trigonal P-3m1 space group. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 11-coordinate geometry to one Cu(2), three equivalent Cu(3), three equivalent Cu(4), and four equivalent Si(1) atoms. In the second Cu site, Cu(2) is bonded in a 11-coordinate geometry to one Cu(1), three equivalent Cu(2), six equivalent Cu(3), and one Si(1) atom. In the third Cu site, Cu(3) is bonded in a 14-coordinate geometry to one Cu(3), one Cu(4), three equivalent Cu(1), six equivalent Cu(2), and three equivalent Si(1) atoms. In the fourth Cu site, Cu(4) is bonded in a 14-coordinate geometry to two equivalent Cu(3), six equivalent Cu(1), and six equivalent Si(1) atoms. Si(1) is bonded in a 11-coordinate geometry to one Cu(2), three equivalent Cu(3), three equivalent Cu(4), and four equivalent Cu(1) atoms. is represented by the CIF file [CIF]
data_Cu7Si2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.085
_cell_length_b   4.085
_cell_length_c   7.587
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   109.637
_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  0.333  0.667  0.155  1.0
  Cu  Cu1  1  0.667  0.333  0.845  1.0
  Cu  Cu2  1  0.333  0.667  0.496  1.0
  Cu  Cu3  1  0.667  0.333  0.504  1.0
  Cu  Cu4  1  0.000  0.000  0.330  1.0
  Cu  Cu5  1  0.000  0.000  0.670  1.0
  Cu  Cu6  1  0.000  0.000  0.000  1.0
  Si  Si7  1  0.333  0.667  0.809  1.0
  Si  Si8  1  0.667  0.333  0.191  1.0
[/CIF]
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