The compound described by Ba5Ta2O9Cl2 crystallizes in the hexagonal P6_3/mmc space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to three equivalent O(1) and four equivalent Cl(1) atoms. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to three equivalent O(2), six equivalent O(1), and one Cl(1) atom. In the third Ba site, Ba(3) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ba(3)O12 cuboctahedra and faces with six equivalent Ta(1)O6 octahedra. Ta(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form distorted TaO6 octahedra that share faces with three equivalent Ba(3)O12 cuboctahedra and  a faceface with one Ta(1)O6 octahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(3), two equivalent Ba(2), and one Ta(1) atom. In the second O site, O(2) is bonded to two equivalent Ba(2), two equivalent Ba(3), and two equivalent Ta(1) atoms to form distorted OBa4Ta2 octahedra that share corners with six equivalent O(2)Ba4Ta2 octahedra, corners with two equivalent Cl(1)Ba5 trigonal bipyramids, and faces with four equivalent O(2)Ba4Ta2 octahedra. The corner-sharing octahedral tilt angles range from 7-60°. Cl(1) is bonded to one Ba(2) and four equivalent Ba(1) atoms to form distorted ClBa5 trigonal bipyramids that share corners with three equivalent O(2)Ba4Ta2 octahedra, corners with six equivalent Cl(1)Ba5 trigonal bipyramids, and edges with three equivalent Cl(1)Ba5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 45°. is represented by the CIF card [CIF]
data_Ba5Ta2Cl2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.045
_cell_length_b   6.045
_cell_length_c   25.100
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   794.408
_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  0.333  0.667  0.418  1.0
  Ba  Ba1  1  0.333  0.667  0.082  1.0
  Ba  Ba2  1  0.333  0.667  0.828  1.0
  Ba  Ba3  1  0.667  0.333  0.582  1.0
  Ba  Ba4  1  0.667  0.333  0.918  1.0
  Ba  Ba5  1  0.667  0.333  0.328  1.0
  Ba  Ba6  1  0.667  0.333  0.172  1.0
  Ba  Ba7  1  0.333  0.667  0.250  1.0
  Ba  Ba8  1  0.667  0.333  0.750  1.0
  Ba  Ba9  1  0.333  0.667  0.672  1.0
  Ta  Ta10  1  0.000  0.000  0.810  1.0
  Ta  Ta11  1  0.000  0.000  0.310  1.0
  Ta  Ta12  1  0.000  0.000  0.190  1.0
  Ta  Ta13  1  0.000  0.000  0.690  1.0
  Cl  Cl14  1  0.333  0.667  0.547  1.0
  Cl  Cl15  1  0.333  0.667  0.953  1.0
  Cl  Cl16  1  0.667  0.333  0.047  1.0
  Cl  Cl17  1  0.667  0.333  0.453  1.0
  O  O18  1  0.162  0.324  0.155  1.0
  O  O19  1  0.704  0.852  0.750  1.0
  O  O20  1  0.838  0.676  0.655  1.0
  O  O21  1  0.852  0.148  0.250  1.0
  O  O22  1  0.162  0.838  0.345  1.0
  O  O23  1  0.162  0.838  0.155  1.0
  O  O24  1  0.838  0.162  0.655  1.0
  O  O25  1  0.324  0.162  0.655  1.0
  O  O26  1  0.838  0.162  0.845  1.0
  O  O27  1  0.852  0.704  0.250  1.0
  O  O28  1  0.296  0.148  0.250  1.0
  O  O29  1  0.324  0.162  0.845  1.0
  O  O30  1  0.148  0.296  0.750  1.0
  O  O31  1  0.838  0.676  0.845  1.0
  O  O32  1  0.162  0.324  0.345  1.0
  O  O33  1  0.676  0.838  0.155  1.0
  O  O34  1  0.148  0.852  0.750  1.0
  O  O35  1  0.676  0.838  0.345  1.0
[/CIF]
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The compound described by Ba5Ta2O9Cl2 crystallizes in the hexagonal P6_3/mmc space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to three equivalent O(1) and four equivalent Cl(1) atoms. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to three equivalent O(2), six equivalent O(1), and one Cl(1) atom. In the third Ba site, Ba(3) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ba(3)O12 cuboctahedra and faces with six equivalent Ta(1)O6 octahedra. Ta(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form distorted TaO6 octahedra that share faces with three equivalent Ba(3)O12 cuboctahedra and  a faceface with one Ta(1)O6 octahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(3), two equivalent Ba(2), and one Ta(1) atom. In the second O site, O(2) is bonded to two equivalent Ba(2), two equivalent Ba(3), and two equivalent Ta(1) atoms to form distorted OBa4Ta2 octahedra that share corners with six equivalent O(2)Ba4Ta2 octahedra, corners with two equivalent Cl(1)Ba5 trigonal bipyramids, and faces with four equivalent O(2)Ba4Ta2 octahedra. The corner-sharing octahedral tilt angles range from 7-60°. Cl(1) is bonded to one Ba(2) and four equivalent Ba(1) atoms to form distorted ClBa5 trigonal bipyramids that share corners with three equivalent O(2)Ba4Ta2 octahedra, corners with six equivalent Cl(1)Ba5 trigonal bipyramids, and edges with three equivalent Cl(1)Ba5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 45°. is represented by the CIF card [CIF]
data_Ba5Ta2Cl2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.045
_cell_length_b   6.045
_cell_length_c   25.100
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   794.408
_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  0.333  0.667  0.418  1.0
  Ba  Ba1  1  0.333  0.667  0.082  1.0
  Ba  Ba2  1  0.333  0.667  0.828  1.0
  Ba  Ba3  1  0.667  0.333  0.582  1.0
  Ba  Ba4  1  0.667  0.333  0.918  1.0
  Ba  Ba5  1  0.667  0.333  0.328  1.0
  Ba  Ba6  1  0.667  0.333  0.172  1.0
  Ba  Ba7  1  0.333  0.667  0.250  1.0
  Ba  Ba8  1  0.667  0.333  0.750  1.0
  Ba  Ba9  1  0.333  0.667  0.672  1.0
  Ta  Ta10  1  0.000  0.000  0.810  1.0
  Ta  Ta11  1  0.000  0.000  0.310  1.0
  Ta  Ta12  1  0.000  0.000  0.190  1.0
  Ta  Ta13  1  0.000  0.000  0.690  1.0
  Cl  Cl14  1  0.333  0.667  0.547  1.0
  Cl  Cl15  1  0.333  0.667  0.953  1.0
  Cl  Cl16  1  0.667  0.333  0.047  1.0
  Cl  Cl17  1  0.667  0.333  0.453  1.0
  O  O18  1  0.162  0.324  0.155  1.0
  O  O19  1  0.704  0.852  0.750  1.0
  O  O20  1  0.838  0.676  0.655  1.0
  O  O21  1  0.852  0.148  0.250  1.0
  O  O22  1  0.162  0.838  0.345  1.0
  O  O23  1  0.162  0.838  0.155  1.0
  O  O24  1  0.838  0.162  0.655  1.0
  O  O25  1  0.324  0.162  0.655  1.0
  O  O26  1  0.838  0.162  0.845  1.0
  O  O27  1  0.852  0.704  0.250  1.0
  O  O28  1  0.296  0.148  0.250  1.0
  O  O29  1  0.324  0.162  0.845  1.0
  O  O30  1  0.148  0.296  0.750  1.0
  O  O31  1  0.838  0.676  0.845  1.0
  O  O32  1  0.162  0.324  0.345  1.0
  O  O33  1  0.676  0.838  0.155  1.0
  O  O34  1  0.148  0.852  0.750  1.0
  O  O35  1  0.676  0.838  0.345  1.0
[/CIF]
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