data_YSiB4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.57
_cell_length_b   4.57
_cell_length_c   4.57
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   YSiB4
_chemical_formula_sum   'Y1 Si1 B4'
_cell_volume   67.32
_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
  Y  Y5  1  0.61  0.61  0.61  1.0
  Si  Si4  1  0.0  0.0  0.0  1.0
  B  B0  1  0.25  0.25  0.21  1.0
  B  B1  1  0.25  0.21  0.25  1.0
  B  B2  1  0.21  0.25  0.25  1.0
  B  B3  1  0.21  0.21  0.21  1.0

data_YSiB4
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.57
_cell_length_b   4.57
_cell_length_c   11.18
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   YSiB4
_chemical_formula_sum   'Y3 Si3 B12'
_cell_volume   201.95
_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
  Y  Y0  3  0.0  0.0  0.39  1.0
  Si  Si1  3  0.0  0.0  0.0  1.0
  B  B2  9  0.03  0.01  0.76  1.0
  B  B3  3  0.0  0.0  0.79  1.0

Y Si B B B B
Y Si B B B B 0 5 o o + 0 5 o + o 0 5 + o o 0 4 o o + 0 4 o + o 0 4 + o o 0 3 o o + 0 3 o + o 0 3 + o o 0 2 o o + 0 2 o + o 0 2 + o o 0 1 o + + 0 1 + o + 0 1 + + o 1 5 o - o 1 5 - o o 1 5 o o - 1 5 o o o 1 4 o - o 1 4 - o o 1 4 o o - 1 4 o o o 1 3 o - o 1 3 - o o 1 3 o o - 1 3 o o o 1 2 o - o 1 2 - o o 1 2 o o - 1 2 o o o 2 3 o o o 2 4 o o o 2 5 o o o 3 4 o o o 3 5 o o o 4 5 o o o 
YB4Si crystallizes in the trigonal R3m space group. Y(1) is bonded in a distorted hexagonal planar geometry to three equivalent B(1) and three equivalent Si(1) atoms. All Y(1)-B(1) bond lengths are 2.59 Å. All Y(1)-Si(1) bond lengths are 2.70 Å. There are two inequivalent B sites. In the first B site, B(2) is bonded in a 4-coordinate geometry to three equivalent B(1) and one Si(1) atom. All B(2)-B(1) bond lengths are 0.31 Å. The B(2)-Si(1) bond length is 2.34 Å. In the second B site, B(1) is bonded in a 2-coordinate geometry to one Y(1), one B(2), and two equivalent B(1) atoms. Both B(1)-B(1) bond lengths are 0.18 Å. Si(1) is bonded to three equivalent Y(1) and one B(2) atom to form corner-sharing SiY3B tetrahedra.