The structure described by Ba3TiTa4O15 crystallizes in the tetragonal P4/mbm space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to one O(5), two equivalent O(2), and four equivalent O(1) atoms. In the second Ba site, Ba(2) is bonded to four equivalent O(3) and eight equivalent O(4) atoms to form BaO12 cuboctahedra that share faces with two equivalent Ba(2)O12 cuboctahedra and faces with eight equivalent Ta(1)O6 octahedra. Ti(1) is bonded to two equivalent O(5) and four equivalent O(1) atoms to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra and corners with four equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-34°. Ta(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form TaO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra, corners with five equivalent Ta(1)O6 octahedra, and faces with two equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 3-40°. There are five inequivalent O sites. In the first O site, O(4) is bonded in a distorted linear geometry to two equivalent Ba(2) and two equivalent Ta(1) atoms. In the second O site, O(5) is bonded in a linear geometry to two equivalent Ba(1) and two equivalent Ti(1) atoms. In the third O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent Ba(1), one Ti(1), and one Ta(1) atom. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Ba(1) and two equivalent Ta(1) atoms. In the fifth O site, O(3) is bonded in a distorted linear geometry to one Ba(2) and two equivalent Ta(1) atoms. is represented by the CIF card [CIF]
data_Ba3Ta4TiO15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.729
_cell_length_b   12.729
_cell_length_c   3.988
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   646.155
_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
  Ba  Ba0  1  0.666  0.166  0.000  1.0
  Ba  Ba1  1  0.334  0.834  0.000  1.0
  Ba  Ba2  1  0.166  0.334  0.000  1.0
  Ba  Ba3  1  0.834  0.666  0.000  1.0
  Ba  Ba4  1  0.500  0.500  0.000  1.0
  Ba  Ba5  1  0.000  0.000  0.000  1.0
  Ta  Ta6  1  0.573  0.717  0.500  1.0
  Ta  Ta7  1  0.427  0.283  0.500  1.0
  Ta  Ta8  1  0.073  0.783  0.500  1.0
  Ta  Ta9  1  0.927  0.217  0.500  1.0
  Ta  Ta10  1  0.283  0.573  0.500  1.0
  Ta  Ta11  1  0.717  0.427  0.500  1.0
  Ta  Ta12  1  0.217  0.073  0.500  1.0
  Ta  Ta13  1  0.783  0.927  0.500  1.0
  Ti  Ti14  1  0.500  0.000  0.500  1.0
  Ti  Ti15  1  0.000  0.500  0.500  1.0
  O  O16  1  0.845  0.506  0.500  1.0
  O  O17  1  0.155  0.494  0.500  1.0
  O  O18  1  0.345  0.994  0.500  1.0
  O  O19  1  0.655  0.006  0.500  1.0
  O  O20  1  0.494  0.845  0.500  1.0
  O  O21  1  0.506  0.155  0.500  1.0
  O  O22  1  0.006  0.345  0.500  1.0
  O  O23  1  0.994  0.655  0.500  1.0
  O  O24  1  0.784  0.284  0.500  1.0
  O  O25  1  0.216  0.716  0.500  1.0
  O  O26  1  0.284  0.216  0.500  1.0
  O  O27  1  0.716  0.784  0.500  1.0
  O  O28  1  0.578  0.707  0.000  1.0
  O  O29  1  0.422  0.293  0.000  1.0
  O  O30  1  0.078  0.793  0.000  1.0
  O  O31  1  0.922  0.207  0.000  1.0
  O  O32  1  0.293  0.578  0.000  1.0
  O  O33  1  0.707  0.422  0.000  1.0
  O  O34  1  0.207  0.078  0.000  1.0
  O  O35  1  0.793  0.922  0.000  1.0
  O  O36  1  0.642  0.568  0.500  1.0
  O  O37  1  0.358  0.432  0.500  1.0
  O  O38  1  0.142  0.932  0.500  1.0
  O  O39  1  0.858  0.068  0.500  1.0
  O  O40  1  0.432  0.642  0.500  1.0
  O  O41  1  0.568  0.358  0.500  1.0
  O  O42  1  0.068  0.142  0.500  1.0
  O  O43  1  0.932  0.858  0.500  1.0
  O  O44  1  0.500  0.000  0.000  1.0
  O  O45  1  0.000  0.500  0.000  1.0
[/CIF]
.
The structure described by Ba3TiTa4O15 crystallizes in the tetragonal P4/mbm space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to one O(5), two equivalent O(2), and four equivalent O(1) atoms. In the second Ba site, Ba(2) is bonded to four equivalent O(3) and eight equivalent O(4) atoms to form BaO12 cuboctahedra that share faces with two equivalent Ba(2)O12 cuboctahedra and faces with eight equivalent Ta(1)O6 octahedra. Ti(1) is bonded to two equivalent O(5) and four equivalent O(1) atoms to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra and corners with four equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-34°. Ta(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form TaO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra, corners with five equivalent Ta(1)O6 octahedra, and faces with two equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 3-40°. There are five inequivalent O sites. In the first O site, O(4) is bonded in a distorted linear geometry to two equivalent Ba(2) and two equivalent Ta(1) atoms. In the second O site, O(5) is bonded in a linear geometry to two equivalent Ba(1) and two equivalent Ti(1) atoms. In the third O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent Ba(1), one Ti(1), and one Ta(1) atom. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Ba(1) and two equivalent Ta(1) atoms. In the fifth O site, O(3) is bonded in a distorted linear geometry to one Ba(2) and two equivalent Ta(1) atoms. is represented by the CIF card [CIF]
data_Ba3Ta4TiO15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.729
_cell_length_b   12.729
_cell_length_c   3.988
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   646.155
_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
  Ba  Ba0  1  0.666  0.166  0.000  1.0
  Ba  Ba1  1  0.334  0.834  0.000  1.0
  Ba  Ba2  1  0.166  0.334  0.000  1.0
  Ba  Ba3  1  0.834  0.666  0.000  1.0
  Ba  Ba4  1  0.500  0.500  0.000  1.0
  Ba  Ba5  1  0.000  0.000  0.000  1.0
  Ta  Ta6  1  0.573  0.717  0.500  1.0
  Ta  Ta7  1  0.427  0.283  0.500  1.0
  Ta  Ta8  1  0.073  0.783  0.500  1.0
  Ta  Ta9  1  0.927  0.217  0.500  1.0
  Ta  Ta10  1  0.283  0.573  0.500  1.0
  Ta  Ta11  1  0.717  0.427  0.500  1.0
  Ta  Ta12  1  0.217  0.073  0.500  1.0
  Ta  Ta13  1  0.783  0.927  0.500  1.0
  Ti  Ti14  1  0.500  0.000  0.500  1.0
  Ti  Ti15  1  0.000  0.500  0.500  1.0
  O  O16  1  0.845  0.506  0.500  1.0
  O  O17  1  0.155  0.494  0.500  1.0
  O  O18  1  0.345  0.994  0.500  1.0
  O  O19  1  0.655  0.006  0.500  1.0
  O  O20  1  0.494  0.845  0.500  1.0
  O  O21  1  0.506  0.155  0.500  1.0
  O  O22  1  0.006  0.345  0.500  1.0
  O  O23  1  0.994  0.655  0.500  1.0
  O  O24  1  0.784  0.284  0.500  1.0
  O  O25  1  0.216  0.716  0.500  1.0
  O  O26  1  0.284  0.216  0.500  1.0
  O  O27  1  0.716  0.784  0.500  1.0
  O  O28  1  0.578  0.707  0.000  1.0
  O  O29  1  0.422  0.293  0.000  1.0
  O  O30  1  0.078  0.793  0.000  1.0
  O  O31  1  0.922  0.207  0.000  1.0
  O  O32  1  0.293  0.578  0.000  1.0
  O  O33  1  0.707  0.422  0.000  1.0
  O  O34  1  0.207  0.078  0.000  1.0
  O  O35  1  0.793  0.922  0.000  1.0
  O  O36  1  0.642  0.568  0.500  1.0
  O  O37  1  0.358  0.432  0.500  1.0
  O  O38  1  0.142  0.932  0.500  1.0
  O  O39  1  0.858  0.068  0.500  1.0
  O  O40  1  0.432  0.642  0.500  1.0
  O  O41  1  0.568  0.358  0.500  1.0
  O  O42  1  0.068  0.142  0.500  1.0
  O  O43  1  0.932  0.858  0.500  1.0
  O  O44  1  0.500  0.000  0.000  1.0
  O  O45  1  0.000  0.500  0.000  1.0
[/CIF]
.