The structure described by Ba2Ti3AlO8 crystallizes in the tetragonal P4/mmm space group. Ba(1) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms to form BaO12 cuboctahedra that share corners with eight equivalent Ba(1)O12 cuboctahedra, faces with five equivalent Ba(1)O12 cuboctahedra, faces with four equivalent Ti(2)O6 octahedra, and faces with four equivalent Ti(1)O5 square pyramids. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(3) and four equivalent O(1) atoms to form TiO5 square pyramids that share  a cornercorner with one Ti(2)O6 octahedra, corners with four equivalent Ti(1)O5 square pyramids, and faces with four equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. In the second Ti site, Ti(2) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form TiO6 octahedra that share corners with four equivalent Ti(2)O6 octahedra, corners with two equivalent Ti(1)O5 square pyramids, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. Al(1) is bonded in a body-centered cubic geometry to eight equivalent O(1) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ba(1), two equivalent Ti(1), and two equivalent Al(1) atoms. In the second O site, O(2) is bonded in a distorted linear geometry to four equivalent Ba(1) and two equivalent Ti(2) atoms. In the third O site, O(3) is bonded to four equivalent Ba(1), one Ti(1), and one Ti(2) atom to form a mixture of distorted corner and edge-sharing OBa4Ti2 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. is represented by the CIF card [CIF]
data_Ba2Ti3AlO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.971
_cell_length_b   3.971
_cell_length_c   11.449
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   180.540
_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
  Ba  Ba0  1  0.500  0.500  0.174  1.0
  Ba  Ba1  1  0.500  0.500  0.826  1.0
  Ti  Ti2  1  0.000  0.000  0.355  1.0
  Ti  Ti3  1  0.000  0.000  0.000  1.0
  Ti  Ti4  1  0.000  0.000  0.645  1.0
  Al  Al5  1  0.500  0.500  0.500  1.0
  O  O6  1  0.000  0.500  0.383  1.0
  O  O7  1  0.500  0.000  0.383  1.0
  O  O8  1  0.500  0.000  0.000  1.0
  O  O9  1  0.000  0.000  0.187  1.0
  O  O10  1  0.000  0.500  0.617  1.0
  O  O11  1  0.500  0.000  0.617  1.0
  O  O12  1  0.000  0.000  0.813  1.0
  O  O13  1  0.000  0.500  0.000  1.0
[/CIF]
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The structure described by Ba2Ti3AlO8 crystallizes in the tetragonal P4/mmm space group. Ba(1) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms to form BaO12 cuboctahedra that share corners with eight equivalent Ba(1)O12 cuboctahedra, faces with five equivalent Ba(1)O12 cuboctahedra, faces with four equivalent Ti(2)O6 octahedra, and faces with four equivalent Ti(1)O5 square pyramids. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(3) and four equivalent O(1) atoms to form TiO5 square pyramids that share  a cornercorner with one Ti(2)O6 octahedra, corners with four equivalent Ti(1)O5 square pyramids, and faces with four equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. In the second Ti site, Ti(2) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form TiO6 octahedra that share corners with four equivalent Ti(2)O6 octahedra, corners with two equivalent Ti(1)O5 square pyramids, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. Al(1) is bonded in a body-centered cubic geometry to eight equivalent O(1) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ba(1), two equivalent Ti(1), and two equivalent Al(1) atoms. In the second O site, O(2) is bonded in a distorted linear geometry to four equivalent Ba(1) and two equivalent Ti(2) atoms. In the third O site, O(3) is bonded to four equivalent Ba(1), one Ti(1), and one Ti(2) atom to form a mixture of distorted corner and edge-sharing OBa4Ti2 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. is represented by the CIF card [CIF]
data_Ba2Ti3AlO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.971
_cell_length_b   3.971
_cell_length_c   11.449
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   180.540
_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
  Ba  Ba0  1  0.500  0.500  0.174  1.0
  Ba  Ba1  1  0.500  0.500  0.826  1.0
  Ti  Ti2  1  0.000  0.000  0.355  1.0
  Ti  Ti3  1  0.000  0.000  0.000  1.0
  Ti  Ti4  1  0.000  0.000  0.645  1.0
  Al  Al5  1  0.500  0.500  0.500  1.0
  O  O6  1  0.000  0.500  0.383  1.0
  O  O7  1  0.500  0.000  0.383  1.0
  O  O8  1  0.500  0.000  0.000  1.0
  O  O9  1  0.000  0.000  0.187  1.0
  O  O10  1  0.000  0.500  0.617  1.0
  O  O11  1  0.500  0.000  0.617  1.0
  O  O12  1  0.000  0.000  0.813  1.0
  O  O13  1  0.000  0.500  0.000  1.0
[/CIF]
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