The crystal structure described by Ba5Ta4O15 crystallizes in the trigonal P-3m1 space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to three equivalent O(1), three equivalent O(3), and six equivalent O(2) atoms to form BaO12 cuboctahedra that share corners with nine equivalent Ba(1)O12 cuboctahedra, faces with three equivalent Ba(2)O12 cuboctahedra, faces with three equivalent Ta(2)O6 octahedra, and faces with four equivalent Ta(1)O6 octahedra. In the second Ba site, Ba(2) is bonded to six equivalent O(2) and six equivalent O(3) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ba(2)O12 cuboctahedra, faces with six equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ta(2)O6 octahedra, and faces with six equivalent Ta(1)O6 octahedra. In the third Ba site, Ba(3) is bonded in a 12-coordinate geometry to three equivalent O(2) and nine equivalent O(1) atoms. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form TaO6 octahedra that share corners with three equivalent Ta(1)O6 octahedra, corners with three equivalent Ta(2)O6 octahedra, faces with three equivalent Ba(2)O12 cuboctahedra, and faces with four equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-9°. In the second Ta site, Ta(2) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form distorted TaO6 octahedra that share corners with three equivalent Ta(1)O6 octahedra,  a faceface with one Ba(2)O12 cuboctahedra, and faces with three equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 9°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ba(1), three equivalent Ba(3), and one Ta(2) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Ba(2), one Ba(3), two equivalent Ba(1), one Ta(1), and one Ta(2) atom. In the third O site, O(3) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Ta(1) atoms. is represented by the CIF card [CIF]
data_Ba5Ta4O15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.820
_cell_length_b   5.820
_cell_length_c   11.885
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   348.602
_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  0.333  0.667  0.789  1.0
  Ba  Ba1  1  0.000  0.000  0.000  1.0
  Ba  Ba2  1  0.667  0.333  0.569  1.0
  Ba  Ba3  1  0.333  0.667  0.431  1.0
  Ba  Ba4  1  0.667  0.333  0.211  1.0
  Ta  Ta5  1  0.667  0.333  0.896  1.0
  Ta  Ta6  1  0.333  0.667  0.104  1.0
  Ta  Ta7  1  1.000  1.000  0.686  1.0
  Ta  Ta8  1  0.000  0.000  0.314  1.0
  O  O9  1  0.326  0.163  0.386  1.0
  O  O10  1  0.831  0.661  0.809  1.0
  O  O11  1  0.837  0.163  0.386  1.0
  O  O12  1  0.831  0.169  0.809  1.0
  O  O13  1  0.163  0.326  0.614  1.0
  O  O14  1  0.500  0.500  0.000  1.0
  O  O15  1  1.000  0.500  0.000  1.0
  O  O16  1  0.837  0.674  0.386  1.0
  O  O17  1  0.500  1.000  0.000  1.0
  O  O18  1  0.661  0.831  0.191  1.0
  O  O19  1  0.339  0.169  0.809  1.0
  O  O20  1  0.169  0.831  0.191  1.0
  O  O21  1  0.169  0.339  0.191  1.0
  O  O22  1  0.163  0.837  0.614  1.0
  O  O23  1  0.674  0.837  0.614  1.0
[/CIF]
.
The crystal structure described by Ba5Ta4O15 crystallizes in the trigonal P-3m1 space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to three equivalent O(1), three equivalent O(3), and six equivalent O(2) atoms to form BaO12 cuboctahedra that share corners with nine equivalent Ba(1)O12 cuboctahedra, faces with three equivalent Ba(2)O12 cuboctahedra, faces with three equivalent Ta(2)O6 octahedra, and faces with four equivalent Ta(1)O6 octahedra. In the second Ba site, Ba(2) is bonded to six equivalent O(2) and six equivalent O(3) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ba(2)O12 cuboctahedra, faces with six equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ta(2)O6 octahedra, and faces with six equivalent Ta(1)O6 octahedra. In the third Ba site, Ba(3) is bonded in a 12-coordinate geometry to three equivalent O(2) and nine equivalent O(1) atoms. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form TaO6 octahedra that share corners with three equivalent Ta(1)O6 octahedra, corners with three equivalent Ta(2)O6 octahedra, faces with three equivalent Ba(2)O12 cuboctahedra, and faces with four equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-9°. In the second Ta site, Ta(2) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form distorted TaO6 octahedra that share corners with three equivalent Ta(1)O6 octahedra,  a faceface with one Ba(2)O12 cuboctahedra, and faces with three equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 9°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ba(1), three equivalent Ba(3), and one Ta(2) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Ba(2), one Ba(3), two equivalent Ba(1), one Ta(1), and one Ta(2) atom. In the third O site, O(3) is bonded in a distorted linear geometry to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Ta(1) atoms. is represented by the CIF card [CIF]
data_Ba5Ta4O15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.820
_cell_length_b   5.820
_cell_length_c   11.885
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   348.602
_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  0.333  0.667  0.789  1.0
  Ba  Ba1  1  0.000  0.000  0.000  1.0
  Ba  Ba2  1  0.667  0.333  0.569  1.0
  Ba  Ba3  1  0.333  0.667  0.431  1.0
  Ba  Ba4  1  0.667  0.333  0.211  1.0
  Ta  Ta5  1  0.667  0.333  0.896  1.0
  Ta  Ta6  1  0.333  0.667  0.104  1.0
  Ta  Ta7  1  1.000  1.000  0.686  1.0
  Ta  Ta8  1  0.000  0.000  0.314  1.0
  O  O9  1  0.326  0.163  0.386  1.0
  O  O10  1  0.831  0.661  0.809  1.0
  O  O11  1  0.837  0.163  0.386  1.0
  O  O12  1  0.831  0.169  0.809  1.0
  O  O13  1  0.163  0.326  0.614  1.0
  O  O14  1  0.500  0.500  0.000  1.0
  O  O15  1  1.000  0.500  0.000  1.0
  O  O16  1  0.837  0.674  0.386  1.0
  O  O17  1  0.500  1.000  0.000  1.0
  O  O18  1  0.661  0.831  0.191  1.0
  O  O19  1  0.339  0.169  0.809  1.0
  O  O20  1  0.169  0.831  0.191  1.0
  O  O21  1  0.169  0.339  0.191  1.0
  O  O22  1  0.163  0.837  0.614  1.0
  O  O23  1  0.674  0.837  0.614  1.0
[/CIF]
.