The material described by Na2SrAl4(B2O7)2 crystallizes in the trigonal P3 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(5) atoms. In the second Na site, Na(2) is bonded to three equivalent O(3) and three equivalent O(5) atoms to form distorted NaO6 octahedra that share corners with three equivalent Al(2)O4 tetrahedra and corners with three equivalent Al(4)O4 tetrahedra. Sr(1) is bonded to three equivalent O(4) and three equivalent O(6) atoms to form SrO6 octahedra that share corners with three equivalent Al(1)O4 tetrahedra and corners with three equivalent Al(3)O4 tetrahedra. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(2) and three equivalent O(6) atoms to form AlO4 tetrahedra that share corners with three equivalent Sr(1)O6 octahedra and  a cornercorner with one Al(4)O4 tetrahedra. The corner-sharing octahedral tilt angles are 66°. In the second Al site, Al(2) is bonded to one O(1) and three equivalent O(5) atoms to form AlO4 tetrahedra that share corners with three equivalent Na(2)O6 octahedra and  a cornercorner with one Al(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 69°. In the third Al site, Al(3) is bonded to one O(1) and three equivalent O(4) atoms to form AlO4 tetrahedra that share corners with three equivalent Sr(1)O6 octahedra and  a cornercorner with one Al(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 65°. In the fourth Al site, Al(4) is bonded to one O(2) and three equivalent O(3) atoms to form AlO4 tetrahedra that share corners with three equivalent Na(2)O6 octahedra and  a cornercorner with one Al(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 68°. There are four inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to three equivalent O(5) atoms. In the second B site, B(2) is bonded in a trigonal planar geometry to three equivalent O(6) atoms. In the third B site, B(3) is bonded in a trigonal planar geometry to three equivalent O(3) atoms. In the fourth B site, B(4) is bonded in a trigonal planar geometry to three equivalent O(4) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to three equivalent Na(1), one Al(2), and one Al(3) atom. In the second O site, O(2) is bonded in a linear geometry to one Al(1) and one Al(4) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Na(2), one Al(4), and one B(3) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Sr(1), one Al(3), and one B(4) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Al(2), and one B(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Sr(1), one Al(1), and one B(2) atom. is represented by the CIF file [CIF]
data_Na2SrAl4(B2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.953
_cell_length_b   4.953
_cell_length_c   15.990
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   339.691
_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
  Na  Na0  1  0.000  0.000  0.294  1.0
  Na  Na1  1  0.000  0.000  0.522  1.0
  Sr  Sr2  1  0.000  0.000  0.991  1.0
  Al  Al3  1  0.333  0.667  0.849  1.0
  Al  Al4  1  0.667  0.333  0.361  1.0
  Al  Al5  1  0.667  0.333  0.145  1.0
  Al  Al6  1  0.333  0.667  0.637  1.0
  B  B7  1  0.333  0.667  0.390  1.0
  B  B8  1  0.667  0.333  0.898  1.0
  B  B9  1  0.667  0.333  0.596  1.0
  B  B10  1  0.333  0.667  0.105  1.0
  O  O11  1  0.667  0.333  0.251  1.0
  O  O12  1  0.333  0.667  0.745  1.0
  O  O13  1  0.611  0.031  0.594  1.0
  O  O14  1  0.420  0.389  0.594  1.0
  O  O15  1  0.969  0.580  0.594  1.0
  O  O16  1  0.377  0.966  0.103  1.0
  O  O17  1  0.589  0.623  0.103  1.0
  O  O18  1  0.034  0.411  0.103  1.0
  O  O19  1  0.359  0.959  0.388  1.0
  O  O20  1  0.599  0.641  0.388  1.0
  O  O21  1  0.042  0.401  0.388  1.0
  O  O22  1  0.590  0.025  0.903  1.0
  O  O23  1  0.435  0.410  0.903  1.0
  O  O24  1  0.975  0.565  0.903  1.0
[/CIF]
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The material described by Na2SrAl4(B2O7)2 crystallizes in the trigonal P3 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to three equivalent O(1) and three equivalent O(5) atoms. In the second Na site, Na(2) is bonded to three equivalent O(3) and three equivalent O(5) atoms to form distorted NaO6 octahedra that share corners with three equivalent Al(2)O4 tetrahedra and corners with three equivalent Al(4)O4 tetrahedra. Sr(1) is bonded to three equivalent O(4) and three equivalent O(6) atoms to form SrO6 octahedra that share corners with three equivalent Al(1)O4 tetrahedra and corners with three equivalent Al(3)O4 tetrahedra. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(2) and three equivalent O(6) atoms to form AlO4 tetrahedra that share corners with three equivalent Sr(1)O6 octahedra and  a cornercorner with one Al(4)O4 tetrahedra. The corner-sharing octahedral tilt angles are 66°. In the second Al site, Al(2) is bonded to one O(1) and three equivalent O(5) atoms to form AlO4 tetrahedra that share corners with three equivalent Na(2)O6 octahedra and  a cornercorner with one Al(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 69°. In the third Al site, Al(3) is bonded to one O(1) and three equivalent O(4) atoms to form AlO4 tetrahedra that share corners with three equivalent Sr(1)O6 octahedra and  a cornercorner with one Al(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 65°. In the fourth Al site, Al(4) is bonded to one O(2) and three equivalent O(3) atoms to form AlO4 tetrahedra that share corners with three equivalent Na(2)O6 octahedra and  a cornercorner with one Al(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 68°. There are four inequivalent B sites. In the first B site, B(1) is bonded in a trigonal planar geometry to three equivalent O(5) atoms. In the second B site, B(2) is bonded in a trigonal planar geometry to three equivalent O(6) atoms. In the third B site, B(3) is bonded in a trigonal planar geometry to three equivalent O(3) atoms. In the fourth B site, B(4) is bonded in a trigonal planar geometry to three equivalent O(4) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to three equivalent Na(1), one Al(2), and one Al(3) atom. In the second O site, O(2) is bonded in a linear geometry to one Al(1) and one Al(4) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Na(2), one Al(4), and one B(3) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Sr(1), one Al(3), and one B(4) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Al(2), and one B(1) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Sr(1), one Al(1), and one B(2) atom. is represented by the CIF file [CIF]
data_Na2SrAl4(B2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.953
_cell_length_b   4.953
_cell_length_c   15.990
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   339.691
_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
  Na  Na0  1  0.000  0.000  0.294  1.0
  Na  Na1  1  0.000  0.000  0.522  1.0
  Sr  Sr2  1  0.000  0.000  0.991  1.0
  Al  Al3  1  0.333  0.667  0.849  1.0
  Al  Al4  1  0.667  0.333  0.361  1.0
  Al  Al5  1  0.667  0.333  0.145  1.0
  Al  Al6  1  0.333  0.667  0.637  1.0
  B  B7  1  0.333  0.667  0.390  1.0
  B  B8  1  0.667  0.333  0.898  1.0
  B  B9  1  0.667  0.333  0.596  1.0
  B  B10  1  0.333  0.667  0.105  1.0
  O  O11  1  0.667  0.333  0.251  1.0
  O  O12  1  0.333  0.667  0.745  1.0
  O  O13  1  0.611  0.031  0.594  1.0
  O  O14  1  0.420  0.389  0.594  1.0
  O  O15  1  0.969  0.580  0.594  1.0
  O  O16  1  0.377  0.966  0.103  1.0
  O  O17  1  0.589  0.623  0.103  1.0
  O  O18  1  0.034  0.411  0.103  1.0
  O  O19  1  0.359  0.959  0.388  1.0
  O  O20  1  0.599  0.641  0.388  1.0
  O  O21  1  0.042  0.401  0.388  1.0
  O  O22  1  0.590  0.025  0.903  1.0
  O  O23  1  0.435  0.410  0.903  1.0
  O  O24  1  0.975  0.565  0.903  1.0
[/CIF]
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