The structure described by Si is Theoretical Carbon Structure-like structured and crystallizes in the cubic I-43m space group. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one Si(1), one Si(3), and two equivalent Si(4) atoms to form corner-sharing SiSi4 tetrahedra. In the second Si site, Si(4) is bonded to four equivalent Si(1) atoms to form distorted corner-sharing SiSi4 tetrahedra. In the third Si site, Si(2) is bonded to four equivalent Si(3) atoms to form corner-sharing SiSi4 tetrahedra. In the fourth Si site, Si(3) is bonded to one Si(2) and three equivalent Si(1) atoms to form corner-sharing SiSi4 tetrahedra. is represented by the CIF card [CIF]
data_Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.704
_cell_length_b   8.704
_cell_length_c   8.704
_cell_angle_alpha   109.471
_cell_angle_beta   109.471
_cell_angle_gamma   109.471
_symmetry_Int_Tables_number   1
_cell_volume   507.627
_cell_formula_units_Z   23
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
  Si  Si0  1  0.831  0.559  0.559  1.0
  Si  Si1  1  0.169  0.728  0.728  1.0
  Si  Si2  1  0.000  0.441  0.272  1.0
  Si  Si3  1  0.559  0.559  0.831  1.0
  Si  Si4  1  0.000  0.272  0.441  1.0
  Si  Si5  1  0.728  0.728  0.169  1.0
  Si  Si6  1  0.441  0.272  0.000  1.0
  Si  Si7  1  0.272  0.441  0.000  1.0
  Si  Si8  1  0.559  0.831  0.559  1.0
  Si  Si9  1  0.272  0.000  0.441  1.0
  Si  Si10  1  0.441  0.000  0.272  1.0
  Si  Si11  1  0.728  0.169  0.728  1.0
  Si  Si12  1  0.000  0.000  0.000  1.0
  Si  Si13  1  0.728  0.728  0.728  1.0
  Si  Si14  1  0.272  0.000  0.000  1.0
  Si  Si15  1  0.000  0.272  0.000  1.0
  Si  Si16  1  0.000  0.000  0.272  1.0
  Si  Si17  1  0.250  0.750  0.500  1.0
  Si  Si18  1  0.750  0.250  0.500  1.0
  Si  Si19  1  0.750  0.500  0.250  1.0
  Si  Si20  1  0.250  0.500  0.750  1.0
  Si  Si21  1  0.500  0.250  0.750  1.0
  Si  Si22  1  0.500  0.750  0.250  1.0
[/CIF]
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The structure described by Si is Theoretical Carbon Structure-like structured and crystallizes in the cubic I-43m space group. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one Si(1), one Si(3), and two equivalent Si(4) atoms to form corner-sharing SiSi4 tetrahedra. In the second Si site, Si(4) is bonded to four equivalent Si(1) atoms to form distorted corner-sharing SiSi4 tetrahedra. In the third Si site, Si(2) is bonded to four equivalent Si(3) atoms to form corner-sharing SiSi4 tetrahedra. In the fourth Si site, Si(3) is bonded to one Si(2) and three equivalent Si(1) atoms to form corner-sharing SiSi4 tetrahedra. is represented by the CIF card [CIF]
data_Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.704
_cell_length_b   8.704
_cell_length_c   8.704
_cell_angle_alpha   109.471
_cell_angle_beta   109.471
_cell_angle_gamma   109.471
_symmetry_Int_Tables_number   1
_cell_volume   507.627
_cell_formula_units_Z   23
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
  Si  Si0  1  0.831  0.559  0.559  1.0
  Si  Si1  1  0.169  0.728  0.728  1.0
  Si  Si2  1  0.000  0.441  0.272  1.0
  Si  Si3  1  0.559  0.559  0.831  1.0
  Si  Si4  1  0.000  0.272  0.441  1.0
  Si  Si5  1  0.728  0.728  0.169  1.0
  Si  Si6  1  0.441  0.272  0.000  1.0
  Si  Si7  1  0.272  0.441  0.000  1.0
  Si  Si8  1  0.559  0.831  0.559  1.0
  Si  Si9  1  0.272  0.000  0.441  1.0
  Si  Si10  1  0.441  0.000  0.272  1.0
  Si  Si11  1  0.728  0.169  0.728  1.0
  Si  Si12  1  0.000  0.000  0.000  1.0
  Si  Si13  1  0.728  0.728  0.728  1.0
  Si  Si14  1  0.272  0.000  0.000  1.0
  Si  Si15  1  0.000  0.272  0.000  1.0
  Si  Si16  1  0.000  0.000  0.272  1.0
  Si  Si17  1  0.250  0.750  0.500  1.0
  Si  Si18  1  0.750  0.250  0.500  1.0
  Si  Si19  1  0.750  0.500  0.250  1.0
  Si  Si20  1  0.250  0.500  0.750  1.0
  Si  Si21  1  0.500  0.250  0.750  1.0
  Si  Si22  1  0.500  0.750  0.250  1.0
[/CIF]
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