The structure described by Bi2Ta2O9 crystallizes in the orthorhombic Cmc2_1 space group. Ta(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(5) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 11-38°. Bi(1) is bonded in a 7-coordinate geometry to one O(2), two equivalent O(1), and four equivalent O(4) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Ta(1) and two equivalent Bi(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Ta(1) and one Bi(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to two equivalent Ta(1) atoms. In the fourth O site, O(4) is bonded to four equivalent Bi(1) atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the fifth O site, O(5) is bonded in a linear geometry to two equivalent Ta(1) atoms. is represented by the CIF file [CIF]
data_Ta2Bi2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.455
_cell_length_b   12.455
_cell_length_c   5.538
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   154.916
_symmetry_Int_Tables_number   1
_cell_volume   364.239
_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
  Ta  Ta0  1  0.824  0.670  0.043  1.0
  Ta  Ta1  1  0.176  0.330  0.543  1.0
  Ta  Ta2  1  0.330  0.176  0.543  1.0
  Ta  Ta3  1  0.670  0.824  0.043  1.0
  Bi  Bi4  1  0.024  0.415  0.939  1.0
  Bi  Bi5  1  0.415  0.024  0.939  1.0
  Bi  Bi6  1  0.585  0.976  0.439  1.0
  Bi  Bi7  1  0.976  0.585  0.439  1.0
  O  O8  1  0.687  0.007  0.061  1.0
  O  O9  1  0.568  0.366  0.840  1.0
  O  O10  1  0.668  0.668  0.071  1.0
  O  O11  1  0.332  0.332  0.571  1.0
  O  O12  1  0.366  0.568  0.840  1.0
  O  O13  1  0.267  0.756  0.222  1.0
  O  O14  1  0.993  0.313  0.561  1.0
  O  O15  1  0.953  0.095  0.286  1.0
  O  O16  1  0.095  0.953  0.286  1.0
  O  O17  1  0.634  0.432  0.340  1.0
  O  O18  1  0.313  0.993  0.561  1.0
  O  O19  1  0.047  0.905  0.786  1.0
  O  O20  1  0.733  0.244  0.722  1.0
  O  O21  1  0.432  0.634  0.340  1.0
  O  O22  1  0.244  0.733  0.722  1.0
  O  O23  1  0.905  0.047  0.786  1.0
  O  O24  1  0.007  0.687  0.061  1.0
  O  O25  1  0.756  0.267  0.222  1.0
[/CIF]
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The structure described by Bi2Ta2O9 crystallizes in the orthorhombic Cmc2_1 space group. Ta(1) is bonded to one O(1), one O(3), two equivalent O(2), and two equivalent O(5) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 11-38°. Bi(1) is bonded in a 7-coordinate geometry to one O(2), two equivalent O(1), and four equivalent O(4) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Ta(1) and two equivalent Bi(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Ta(1) and one Bi(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to two equivalent Ta(1) atoms. In the fourth O site, O(4) is bonded to four equivalent Bi(1) atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the fifth O site, O(5) is bonded in a linear geometry to two equivalent Ta(1) atoms. is represented by the CIF file [CIF]
data_Ta2Bi2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.455
_cell_length_b   12.455
_cell_length_c   5.538
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   154.916
_symmetry_Int_Tables_number   1
_cell_volume   364.239
_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
  Ta  Ta0  1  0.824  0.670  0.043  1.0
  Ta  Ta1  1  0.176  0.330  0.543  1.0
  Ta  Ta2  1  0.330  0.176  0.543  1.0
  Ta  Ta3  1  0.670  0.824  0.043  1.0
  Bi  Bi4  1  0.024  0.415  0.939  1.0
  Bi  Bi5  1  0.415  0.024  0.939  1.0
  Bi  Bi6  1  0.585  0.976  0.439  1.0
  Bi  Bi7  1  0.976  0.585  0.439  1.0
  O  O8  1  0.687  0.007  0.061  1.0
  O  O9  1  0.568  0.366  0.840  1.0
  O  O10  1  0.668  0.668  0.071  1.0
  O  O11  1  0.332  0.332  0.571  1.0
  O  O12  1  0.366  0.568  0.840  1.0
  O  O13  1  0.267  0.756  0.222  1.0
  O  O14  1  0.993  0.313  0.561  1.0
  O  O15  1  0.953  0.095  0.286  1.0
  O  O16  1  0.095  0.953  0.286  1.0
  O  O17  1  0.634  0.432  0.340  1.0
  O  O18  1  0.313  0.993  0.561  1.0
  O  O19  1  0.047  0.905  0.786  1.0
  O  O20  1  0.733  0.244  0.722  1.0
  O  O21  1  0.432  0.634  0.340  1.0
  O  O22  1  0.244  0.733  0.722  1.0
  O  O23  1  0.905  0.047  0.786  1.0
  O  O24  1  0.007  0.687  0.061  1.0
  O  O25  1  0.756  0.267  0.222  1.0
[/CIF]
.