The structure described by Ba3TiAl10O20 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 6-coordinate geometry to two equivalent O(4) and four equivalent O(2) atoms. In the second Ba site, Ba(2) is bonded in a 9-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), and four equivalent O(5) atoms. Ti(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form TiO6 octahedra that share corners with four equivalent Al(1)O4 tetrahedra and edges with four equivalent Al(2)O6 octahedra. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form AlO4 tetrahedra that share  a cornercorner with one Ti(1)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, and corners with three equivalent Al(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 41-64°. In the second Al site, Al(2) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(6) atoms to form AlO6 octahedra that share corners with two equivalent Al(3)O4 tetrahedra, corners with four equivalent Al(1)O4 tetrahedra,  an edgeedge with one Al(2)O6 octahedra, and edges with two equivalent Ti(1)O6 octahedra. In the third Al site, Al(3) is bonded to one O(2), one O(4), one O(5), and one O(6) atom to form AlO4 tetrahedra that share  a cornercorner with one Al(2)O6 octahedra,  a cornercorner with one Al(3)O4 tetrahedra, and corners with three equivalent Al(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 51°. There are six inequivalent O sites. In the first O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Ba(2), one Al(1), and one Al(3) atom. In the second O site, O(3) is bonded to one Ba(2), one Ti(1), and two equivalent Al(2) atoms to form a mixture of distorted corner and edge-sharing OBaTiAl2 tetrahedra. In the third O site, O(4) is bonded in a 2-coordinate geometry to one Ba(1) and two equivalent Al(3) atoms. In the fourth O site, O(5) is bonded in a distorted bent 150 degrees geometry to two equivalent Ba(2), one Al(1), and one Al(3) atom. In the fifth O site, O(6) is bonded in a trigonal planar geometry to one Al(1), one Al(2), and one Al(3) atom. In the sixth O site, O(1) is bonded in a 3-coordinate geometry to one Ba(2), one Ti(1), one Al(1), and one Al(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba3TiAl10O20
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.770
_cell_length_b   9.770
_cell_length_c   5.028
_cell_angle_alpha   75.609
_cell_angle_beta   75.609
_cell_angle_gamma   72.073
_symmetry_Int_Tables_number   1
_cell_volume   434.563
_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  0.000  0.000  0.000  1.0
  Ba  Ba1  1  0.278  0.278  0.750  1.0
  Ba  Ba2  1  0.722  0.722  0.250  1.0
  Ti  Ti3  1  0.500  0.500  0.000  1.0
  Al  Al4  1  0.850  0.424  0.837  1.0
  Al  Al5  1  0.576  0.150  0.163  1.0
  Al  Al6  1  0.150  0.576  0.163  1.0
  Al  Al7  1  0.424  0.850  0.837  1.0
  Al  Al8  1  0.364  0.636  0.500  1.0
  Al  Al9  1  0.636  0.364  0.500  1.0
  Al  Al10  1  0.993  0.713  0.659  1.0
  Al  Al11  1  0.287  0.007  0.341  1.0
  Al  Al12  1  0.007  0.287  0.341  1.0
  Al  Al13  1  0.713  0.993  0.659  1.0
  O  O14  1  0.553  0.306  0.887  1.0
  O  O15  1  0.694  0.447  0.113  1.0
  O  O16  1  0.447  0.694  0.113  1.0
  O  O17  1  0.306  0.553  0.887  1.0
  O  O18  1  0.710  0.013  0.001  1.0
  O  O19  1  0.987  0.290  0.999  1.0
  O  O20  1  0.290  0.987  0.999  1.0
  O  O21  1  0.013  0.710  0.001  1.0
  O  O22  1  0.437  0.437  0.393  1.0
  O  O23  1  0.563  0.563  0.607  1.0
  O  O24  1  0.893  0.893  0.533  1.0
  O  O25  1  0.107  0.107  0.467  1.0
  O  O26  1  0.882  0.596  0.694  1.0
  O  O27  1  0.404  0.118  0.306  1.0
  O  O28  1  0.118  0.404  0.306  1.0
  O  O29  1  0.596  0.882  0.694  1.0
  O  O30  1  0.170  0.658  0.434  1.0
  O  O31  1  0.342  0.830  0.566  1.0
  O  O32  1  0.830  0.342  0.566  1.0
  O  O33  1  0.658  0.170  0.434  1.0
[/CIF]
.
The structure described by Ba3TiAl10O20 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 6-coordinate geometry to two equivalent O(4) and four equivalent O(2) atoms. In the second Ba site, Ba(2) is bonded in a 9-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), and four equivalent O(5) atoms. Ti(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form TiO6 octahedra that share corners with four equivalent Al(1)O4 tetrahedra and edges with four equivalent Al(2)O6 octahedra. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form AlO4 tetrahedra that share  a cornercorner with one Ti(1)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, and corners with three equivalent Al(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 41-64°. In the second Al site, Al(2) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(6) atoms to form AlO6 octahedra that share corners with two equivalent Al(3)O4 tetrahedra, corners with four equivalent Al(1)O4 tetrahedra,  an edgeedge with one Al(2)O6 octahedra, and edges with two equivalent Ti(1)O6 octahedra. In the third Al site, Al(3) is bonded to one O(2), one O(4), one O(5), and one O(6) atom to form AlO4 tetrahedra that share  a cornercorner with one Al(2)O6 octahedra,  a cornercorner with one Al(3)O4 tetrahedra, and corners with three equivalent Al(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 51°. There are six inequivalent O sites. In the first O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Ba(2), one Al(1), and one Al(3) atom. In the second O site, O(3) is bonded to one Ba(2), one Ti(1), and two equivalent Al(2) atoms to form a mixture of distorted corner and edge-sharing OBaTiAl2 tetrahedra. In the third O site, O(4) is bonded in a 2-coordinate geometry to one Ba(1) and two equivalent Al(3) atoms. In the fourth O site, O(5) is bonded in a distorted bent 150 degrees geometry to two equivalent Ba(2), one Al(1), and one Al(3) atom. In the fifth O site, O(6) is bonded in a trigonal planar geometry to one Al(1), one Al(2), and one Al(3) atom. In the sixth O site, O(1) is bonded in a 3-coordinate geometry to one Ba(2), one Ti(1), one Al(1), and one Al(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba3TiAl10O20
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.770
_cell_length_b   9.770
_cell_length_c   5.028
_cell_angle_alpha   75.609
_cell_angle_beta   75.609
_cell_angle_gamma   72.073
_symmetry_Int_Tables_number   1
_cell_volume   434.563
_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  0.000  0.000  0.000  1.0
  Ba  Ba1  1  0.278  0.278  0.750  1.0
  Ba  Ba2  1  0.722  0.722  0.250  1.0
  Ti  Ti3  1  0.500  0.500  0.000  1.0
  Al  Al4  1  0.850  0.424  0.837  1.0
  Al  Al5  1  0.576  0.150  0.163  1.0
  Al  Al6  1  0.150  0.576  0.163  1.0
  Al  Al7  1  0.424  0.850  0.837  1.0
  Al  Al8  1  0.364  0.636  0.500  1.0
  Al  Al9  1  0.636  0.364  0.500  1.0
  Al  Al10  1  0.993  0.713  0.659  1.0
  Al  Al11  1  0.287  0.007  0.341  1.0
  Al  Al12  1  0.007  0.287  0.341  1.0
  Al  Al13  1  0.713  0.993  0.659  1.0
  O  O14  1  0.553  0.306  0.887  1.0
  O  O15  1  0.694  0.447  0.113  1.0
  O  O16  1  0.447  0.694  0.113  1.0
  O  O17  1  0.306  0.553  0.887  1.0
  O  O18  1  0.710  0.013  0.001  1.0
  O  O19  1  0.987  0.290  0.999  1.0
  O  O20  1  0.290  0.987  0.999  1.0
  O  O21  1  0.013  0.710  0.001  1.0
  O  O22  1  0.437  0.437  0.393  1.0
  O  O23  1  0.563  0.563  0.607  1.0
  O  O24  1  0.893  0.893  0.533  1.0
  O  O25  1  0.107  0.107  0.467  1.0
  O  O26  1  0.882  0.596  0.694  1.0
  O  O27  1  0.404  0.118  0.306  1.0
  O  O28  1  0.118  0.404  0.306  1.0
  O  O29  1  0.596  0.882  0.694  1.0
  O  O30  1  0.170  0.658  0.434  1.0
  O  O31  1  0.342  0.830  0.566  1.0
  O  O32  1  0.830  0.342  0.566  1.0
  O  O33  1  0.658  0.170  0.434  1.0
[/CIF]
.