data_BeSiB2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.67
_cell_length_b   3.67
_cell_length_c   3.67
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BeSiB2
_chemical_formula_sum   'Be1 Si1 B2'
_cell_volume   35.08
_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
  Be  Be2  1  0.0  0.0  0.0  1.0
  Si  Si3  1  0.3  0.3  0.3  1.0
  B  B0  1  0.6  0.6  0.6  1.0
  B  B1  1  0.9  0.9  0.9  1.0

data_BeSiB2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   3.67
_cell_length_b   3.67
_cell_length_c   9.0
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   BeSiB2
_chemical_formula_sum   'Be3 Si3 B6'
_cell_volume   105.24
_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
  Be  Be0  3  0.0  0.0  0.0  1.0
  Si  Si1  3  0.0  0.0  0.7  1.0
  B  B2  3  0.0  0.0  0.1  1.0
  B  B3  3  0.0  0.0  0.4  1.0

Be Si B B
Be Si B B 0 3 - - - 0 1 o o - 0 1 o - o 0 1 - o o 0 2 o - - 0 2 - o - 0 2 - - o 1 3 - - o 1 3 - o - 1 3 o - - 1 2 - o o 1 2 o - o 1 2 o o - 2 3 - o o 2 3 o - o 2 3 o o - 
BeB2Si crystallizes in the trigonal R3m space group. Be(1) is bonded in a single-bond geometry to one B(2), three equivalent B(1), and four equivalent Si(1) atoms. The Be(1)-B(2) bond length is 0.92 Å. All Be(1)-B(1) bond lengths are 2.21 Å. There are three shorter (2.14 Å) and one longer (2.69 Å) Be(1)-Si(1) bond length. There are two inequivalent B sites. In the first B site, B(1) is bonded in a 10-coordinate geometry to three equivalent Be(1), three equivalent B(2), and four equivalent Si(1) atoms. All B(1)-B(2) bond lengths are 2.14 Å. There are three shorter (2.14 Å) and one longer (2.69 Å) B(1)-Si(1) bond length. In the second B site, B(2) is bonded in a single-bond geometry to one Be(1), three equivalent B(1), and three equivalent Si(1) atoms. All B(2)-Si(1) bond lengths are 2.21 Å. Si(1) is bonded in a 11-coordinate geometry to four equivalent Be(1), three equivalent B(2), and four equivalent B(1) atoms.