The compound described by SrAl2B2O7 crystallizes in the trigonal R-3c space group. Sr(1) is bonded to six equivalent O(1) atoms to form SrO6 octahedra that share corners with six equivalent Al(1)O4 tetrahedra. Al(1) is bonded to one O(2) and three equivalent O(1) atoms to form AlO4 tetrahedra that share corners with three equivalent Sr(1)O6 octahedra and  a cornercorner with one Al(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 65°. B(1) is bonded in a trigonal planar geometry to three equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(2) is bonded in a linear geometry to two equivalent Al(1) atoms. In the second O site, O(1) is bonded in a 3-coordinate geometry to one Sr(1), one Al(1), and one B(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_SrAl2B2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   16.429
_cell_length_b   16.429
_cell_length_c   16.429
_cell_angle_alpha   17.345
_cell_angle_beta   17.345
_cell_angle_gamma   17.345
_symmetry_Int_Tables_number   1
_cell_volume   343.940
_cell_formula_units_Z   2
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  Sr0  1  0.000  0.000  0.000  1.0
  Sr  Sr1  1  0.500  0.500  0.500  1.0
  Al  Al2  1  0.215  0.215  0.215  1.0
  Al  Al3  1  0.285  0.285  0.285  1.0
  Al  Al4  1  0.785  0.785  0.785  1.0
  Al  Al5  1  0.715  0.715  0.715  1.0
  B  B6  1  0.133  0.133  0.133  1.0
  B  B7  1  0.633  0.633  0.633  1.0
  B  B8  1  0.867  0.867  0.867  1.0
  B  B9  1  0.367  0.367  0.367  1.0
  O  O10  1  0.437  0.890  0.074  1.0
  O  O11  1  0.890  0.074  0.437  1.0
  O  O12  1  0.574  0.390  0.937  1.0
  O  O13  1  0.750  0.750  0.750  1.0
  O  O14  1  0.390  0.937  0.574  1.0
  O  O15  1  0.426  0.610  0.063  1.0
  O  O16  1  0.937  0.574  0.390  1.0
  O  O17  1  0.110  0.926  0.563  1.0
  O  O18  1  0.563  0.110  0.926  1.0
  O  O19  1  0.074  0.437  0.890  1.0
  O  O20  1  0.926  0.563  0.110  1.0
  O  O21  1  0.063  0.426  0.610  1.0
  O  O22  1  0.610  0.063  0.426  1.0
  O  O23  1  0.250  0.250  0.250  1.0
[/CIF]
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The compound described by SrAl2B2O7 crystallizes in the trigonal R-3c space group. Sr(1) is bonded to six equivalent O(1) atoms to form SrO6 octahedra that share corners with six equivalent Al(1)O4 tetrahedra. Al(1) is bonded to one O(2) and three equivalent O(1) atoms to form AlO4 tetrahedra that share corners with three equivalent Sr(1)O6 octahedra and  a cornercorner with one Al(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 65°. B(1) is bonded in a trigonal planar geometry to three equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(2) is bonded in a linear geometry to two equivalent Al(1) atoms. In the second O site, O(1) is bonded in a 3-coordinate geometry to one Sr(1), one Al(1), and one B(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_SrAl2B2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   16.429
_cell_length_b   16.429
_cell_length_c   16.429
_cell_angle_alpha   17.345
_cell_angle_beta   17.345
_cell_angle_gamma   17.345
_symmetry_Int_Tables_number   1
_cell_volume   343.940
_cell_formula_units_Z   2
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  Sr0  1  0.000  0.000  0.000  1.0
  Sr  Sr1  1  0.500  0.500  0.500  1.0
  Al  Al2  1  0.215  0.215  0.215  1.0
  Al  Al3  1  0.285  0.285  0.285  1.0
  Al  Al4  1  0.785  0.785  0.785  1.0
  Al  Al5  1  0.715  0.715  0.715  1.0
  B  B6  1  0.133  0.133  0.133  1.0
  B  B7  1  0.633  0.633  0.633  1.0
  B  B8  1  0.867  0.867  0.867  1.0
  B  B9  1  0.367  0.367  0.367  1.0
  O  O10  1  0.437  0.890  0.074  1.0
  O  O11  1  0.890  0.074  0.437  1.0
  O  O12  1  0.574  0.390  0.937  1.0
  O  O13  1  0.750  0.750  0.750  1.0
  O  O14  1  0.390  0.937  0.574  1.0
  O  O15  1  0.426  0.610  0.063  1.0
  O  O16  1  0.937  0.574  0.390  1.0
  O  O17  1  0.110  0.926  0.563  1.0
  O  O18  1  0.563  0.110  0.926  1.0
  O  O19  1  0.074  0.437  0.890  1.0
  O  O20  1  0.926  0.563  0.110  1.0
  O  O21  1  0.063  0.426  0.610  1.0
  O  O22  1  0.610  0.063  0.426  1.0
  O  O23  1  0.250  0.250  0.250  1.0
[/CIF]
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