The material described by SiB4 crystallizes in the trigonal R-3m space group. There are two inequivalent B sites. In the first B site, B(1) is bonded in a 6-coordinate geometry to two equivalent B(1), three equivalent B(2), one Si(1), and one Si(2) atom. In the second B site, B(2) is bonded in a 6-coordinate geometry to three equivalent B(1) and three equivalent B(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 4-coordinate geometry to three equivalent B(1) and one Si(2) atom. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to six equivalent B(1) and two equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_SiB4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.492
_cell_length_b   5.492
_cell_length_c   5.492
_cell_angle_alpha   68.969
_cell_angle_beta   68.969
_cell_angle_gamma   68.969
_symmetry_Int_Tables_number   1
_cell_volume   139.188
_cell_formula_units_Z   3
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  0.326  0.326  0.326  1.0
  Si  Si1  1  0.674  0.674  0.674  1.0
  Si  Si2  1  0.500  0.500  0.500  1.0
  B  B3  1  0.275  0.823  0.823  1.0
  B  B4  1  0.823  0.823  0.275  1.0
  B  B5  1  0.823  0.275  0.823  1.0
  B  B6  1  0.177  0.725  0.177  1.0
  B  B7  1  0.177  0.177  0.725  1.0
  B  B8  1  0.725  0.177  0.177  1.0
  B  B9  1  0.677  0.986  0.986  1.0
  B  B10  1  0.986  0.986  0.677  1.0
  B  B11  1  0.986  0.677  0.986  1.0
  B  B12  1  0.014  0.323  0.014  1.0
  B  B13  1  0.014  0.014  0.323  1.0
  B  B14  1  0.323  0.014  0.014  1.0
[/CIF]
.
The material described by SiB4 crystallizes in the trigonal R-3m space group. There are two inequivalent B sites. In the first B site, B(1) is bonded in a 6-coordinate geometry to two equivalent B(1), three equivalent B(2), one Si(1), and one Si(2) atom. In the second B site, B(2) is bonded in a 6-coordinate geometry to three equivalent B(1) and three equivalent B(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 4-coordinate geometry to three equivalent B(1) and one Si(2) atom. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to six equivalent B(1) and two equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_SiB4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.492
_cell_length_b   5.492
_cell_length_c   5.492
_cell_angle_alpha   68.969
_cell_angle_beta   68.969
_cell_angle_gamma   68.969
_symmetry_Int_Tables_number   1
_cell_volume   139.188
_cell_formula_units_Z   3
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  0.326  0.326  0.326  1.0
  Si  Si1  1  0.674  0.674  0.674  1.0
  Si  Si2  1  0.500  0.500  0.500  1.0
  B  B3  1  0.275  0.823  0.823  1.0
  B  B4  1  0.823  0.823  0.275  1.0
  B  B5  1  0.823  0.275  0.823  1.0
  B  B6  1  0.177  0.725  0.177  1.0
  B  B7  1  0.177  0.177  0.725  1.0
  B  B8  1  0.725  0.177  0.177  1.0
  B  B9  1  0.677  0.986  0.986  1.0
  B  B10  1  0.986  0.986  0.677  1.0
  B  B11  1  0.986  0.677  0.986  1.0
  B  B12  1  0.014  0.323  0.014  1.0
  B  B13  1  0.014  0.014  0.323  1.0
  B  B14  1  0.323  0.014  0.014  1.0
[/CIF]
.