data_SrSiB2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.51
_cell_length_b   4.51
_cell_length_c   4.51
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrSiB2
_chemical_formula_sum   'Sr1 Si1 B2'
_cell_volume   64.72
_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
  Sr  Sr3  1  0.59  0.59  0.59  1.0
  Si  Si2  1  0.19  0.19  0.19  1.0
  B  B0  1  0.0  0.0  0.0  1.0
  B  B1  1  0.78  0.78  0.78  1.0

data_SrSiB2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.51
_cell_length_b   4.51
_cell_length_c   11.04
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   SrSiB2
_chemical_formula_sum   'Sr3 Si3 B6'
_cell_volume   194.16
_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
  Sr  Sr0  3  0.0  0.0  0.41  1.0
  Si  Si1  3  0.0  0.0  0.81  1.0
  B  B2  3  0.0  0.0  0.0  1.0
  B  B3  3  0.0  0.0  0.22  1.0

Sr Si B B
Sr Si B B 0 1 o o + 0 1 o + o 0 1 + o o 0 2 o + + 0 2 + o + 0 2 + + o 0 3 o o o 1 2 o o o 1 3 - - o 1 3 - o - 1 3 o - - 2 3 - - - 
SrB2Si crystallizes in the trigonal R3m space group. Sr(1) is bonded in a distorted single-bond geometry to one B(2), three equivalent B(1), and three equivalent Si(1) atoms. The Sr(1)-B(2) bond length is 2.06 Å. All Sr(1)-B(1) bond lengths are 2.72 Å. All Sr(1)-Si(1) bond lengths are 2.72 Å. There are two inequivalent B sites. In the first B site, B(1) is bonded to three equivalent Sr(1) and one Si(1) atom to form distorted BSr3Si tetrahedra that share corners with three equivalent Si(1)Sr3B tetrahedra, corners with six equivalent B(1)Sr3Si tetrahedra, and edges with three equivalent Si(1)Sr3B tetrahedra. The B(1)-Si(1) bond length is 2.06 Å. In the second B site, B(2) is bonded in a single-bond geometry to one Sr(1) atom. Si(1) is bonded to three equivalent Sr(1) and one B(1) atom to form SiSr3B tetrahedra that share corners with three equivalent B(1)Sr3Si tetrahedra, corners with six equivalent Si(1)Sr3B tetrahedra, and edges with three equivalent B(1)Sr3Si tetrahedra.