data_RbSiB2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.52
_cell_length_b   4.52
_cell_length_c   4.52
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   RbSiB2
_chemical_formula_sum   'Rb1 Si1 B2'
_cell_volume   65.2
_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
  Rb  Rb2  1  0.19  0.19  0.19  1.0
  Si  Si3  1  0.0  0.0  0.0  1.0
  B  B0  1  0.6  0.6  0.6  1.0
  B  B1  1  0.79  0.79  0.79  1.0

data_RbSiB2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.52
_cell_length_b   4.52
_cell_length_c   11.07
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   RbSiB2
_chemical_formula_sum   'Rb3 Si3 B6'
_cell_volume   195.61
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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
  Rb  Rb0  3  0.0  0.0  0.81  1.0
  Si  Si1  3  0.0  0.0  0.0  1.0
  B  B2  3  0.0  0.0  0.21  1.0
  B  B3  3  0.0  0.0  0.4  1.0

Rb Si B B
Rb Si B B 0 1 o o o 0 1 o o + 0 1 + o o 0 1 o + o 0 3 - - o 0 3 - o - 0 3 o - - 0 2 - o o 0 2 o - o 0 2 o o - 1 3 - - - 1 2 - - o 1 2 - o - 1 2 o - - 2 3 o - o 2 3 - o o 2 3 o o - 2 3 o o o 
RbB2Si crystallizes in the trigonal R3m space group. Rb(1) is bonded in a 1-coordinate geometry to three equivalent B(1), three equivalent B(2), and one Si(1) atom. All Rb(1)-B(1) bond lengths are 2.72 Å. All Rb(1)-B(2) bond lengths are 2.72 Å. The Rb(1)-Si(1) bond length is 2.15 Å. There are two inequivalent B sites. In the first B site, B(1) is bonded to three equivalent Rb(1) and one B(2) atom to form distorted corner-sharing BRb3B tetrahedra. The B(1)-B(2) bond length is 2.15 Å. In the second B site, B(2) is bonded in a distorted pentagonal planar geometry to three equivalent Rb(1), one B(1), and one Si(1) atom. The B(2)-Si(1) bond length is 2.30 Å. Si(1) is bonded in a 1-coordinate geometry to one Rb(1) and one B(2) atom.