The material described by Si is Lonsdaleite structured and crystallizes in the hexagonal P6_3/mmc space group. Si(1) is bonded to four equivalent Si(1) atoms to form corner-sharing SiSi4 tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.831
_cell_length_b   3.831
_cell_length_c   6.333
_cell_angle_alpha   90.001
_cell_angle_beta   89.999
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   80.503
_cell_formula_units_Z   4
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  0.667  0.333  0.500  1.0
  Si  Si1  1  0.000  1.000  0.000  1.0
  Si  Si2  1  0.667  0.333  0.874  1.0
  Si  Si3  1  0.000  1.000  0.374  1.0
[/CIF]
.
The material described by Si is Lonsdaleite structured and crystallizes in the hexagonal P6_3/mmc space group. Si(1) is bonded to four equivalent Si(1) atoms to form corner-sharing SiSi4 tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.831
_cell_length_b   3.831
_cell_length_c   6.333
_cell_angle_alpha   90.001
_cell_angle_beta   89.999
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   80.503
_cell_formula_units_Z   4
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  0.667  0.333  0.500  1.0
  Si  Si1  1  0.000  1.000  0.000  1.0
  Si  Si2  1  0.667  0.333  0.874  1.0
  Si  Si3  1  0.000  1.000  0.374  1.0
[/CIF]
.