The crystal structure described by TlTaO3 crystallizes in the monoclinic C2/c space group. There are four inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 37-40°. In the second Ta site, Ta(2) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 36-40°. In the third Ta site, Ta(3) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 37-40°. In the fourth Ta site, Ta(4) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(6) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 36-40°. There are three inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(6) atom. In the second Tl site, Tl(2) is bonded in a distorted hexagonal planar geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms. In the third Tl site, Tl(3) is bonded in a 4-coordinate geometry to two equivalent O(5) and two equivalent O(6) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ta(1), one Ta(4), and one Tl(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Ta(1), one Ta(3), one Tl(1), and one Tl(2) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Ta(1), one Ta(2), one Tl(1), and one Tl(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Ta(2), one Ta(4), and one Tl(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Ta(2), one Ta(3), one Tl(2), and one Tl(3) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Ta(3), one Ta(4), one Tl(1), and one Tl(3) atom. is represented by the CIF file [CIF]
data_TaTlO3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.540
_cell_length_b   7.540
_cell_length_c   13.062
_cell_angle_alpha   72.934
_cell_angle_beta   72.934
_cell_angle_gamma   60.019
_symmetry_Int_Tables_number   1
_cell_volume   605.216
_cell_formula_units_Z   8
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  0.500  0.000  0.500  1.0
  Ta  Ta1  1  0.500  0.500  0.500  1.0
  Ta  Ta2  1  0.000  0.000  0.000  1.0
  Ta  Ta3  1  0.000  0.000  0.500  1.0
  Ta  Ta4  1  0.252  0.748  0.750  1.0
  Ta  Ta5  1  0.000  0.500  0.000  1.0
  Ta  Ta6  1  0.748  0.252  0.250  1.0
  Ta  Ta7  1  0.500  0.500  0.000  1.0
  Tl  Tl8  1  0.807  0.671  0.741  1.0
  Tl  Tl9  1  0.000  0.500  0.500  1.0
  Tl  Tl10  1  0.764  0.236  0.750  1.0
  Tl  Tl11  1  0.671  0.807  0.241  1.0
  Tl  Tl12  1  0.500  0.000  0.000  1.0
  Tl  Tl13  1  0.329  0.193  0.759  1.0
  Tl  Tl14  1  0.236  0.764  0.250  1.0
  Tl  Tl15  1  0.193  0.329  0.259  1.0
  O  O16  1  0.099  0.590  0.845  1.0
  O  O17  1  0.780  0.911  0.529  1.0
  O  O18  1  0.407  0.279  0.534  1.0
  O  O19  1  0.463  0.594  0.846  1.0
  O  O20  1  0.720  0.220  0.970  1.0
  O  O21  1  0.590  0.099  0.345  1.0
  O  O22  1  0.279  0.407  0.034  1.0
  O  O23  1  0.406  0.537  0.654  1.0
  O  O24  1  0.098  0.970  0.843  1.0
  O  O25  1  0.780  0.280  0.530  1.0
  O  O26  1  0.911  0.780  0.029  1.0
  O  O27  1  0.030  0.902  0.657  1.0
  O  O28  1  0.089  0.220  0.971  1.0
  O  O29  1  0.970  0.098  0.343  1.0
  O  O30  1  0.220  0.720  0.470  1.0
  O  O31  1  0.902  0.030  0.157  1.0
  O  O32  1  0.594  0.463  0.346  1.0
  O  O33  1  0.721  0.593  0.966  1.0
  O  O34  1  0.280  0.780  0.030  1.0
  O  O35  1  0.410  0.901  0.655  1.0
  O  O36  1  0.537  0.406  0.154  1.0
  O  O37  1  0.593  0.721  0.466  1.0
  O  O38  1  0.220  0.089  0.471  1.0
  O  O39  1  0.901  0.410  0.155  1.0
[/CIF]
.
The crystal structure described by TlTaO3 crystallizes in the monoclinic C2/c space group. There are four inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 37-40°. In the second Ta site, Ta(2) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 36-40°. In the third Ta site, Ta(3) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 37-40°. In the fourth Ta site, Ta(4) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(6) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 36-40°. There are three inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(6) atom. In the second Tl site, Tl(2) is bonded in a distorted hexagonal planar geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms. In the third Tl site, Tl(3) is bonded in a 4-coordinate geometry to two equivalent O(5) and two equivalent O(6) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ta(1), one Ta(4), and one Tl(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Ta(1), one Ta(3), one Tl(1), and one Tl(2) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Ta(1), one Ta(2), one Tl(1), and one Tl(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Ta(2), one Ta(4), and one Tl(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Ta(2), one Ta(3), one Tl(2), and one Tl(3) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Ta(3), one Ta(4), one Tl(1), and one Tl(3) atom. is represented by the CIF file [CIF]
data_TaTlO3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.540
_cell_length_b   7.540
_cell_length_c   13.062
_cell_angle_alpha   72.934
_cell_angle_beta   72.934
_cell_angle_gamma   60.019
_symmetry_Int_Tables_number   1
_cell_volume   605.216
_cell_formula_units_Z   8
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  0.500  0.000  0.500  1.0
  Ta  Ta1  1  0.500  0.500  0.500  1.0
  Ta  Ta2  1  0.000  0.000  0.000  1.0
  Ta  Ta3  1  0.000  0.000  0.500  1.0
  Ta  Ta4  1  0.252  0.748  0.750  1.0
  Ta  Ta5  1  0.000  0.500  0.000  1.0
  Ta  Ta6  1  0.748  0.252  0.250  1.0
  Ta  Ta7  1  0.500  0.500  0.000  1.0
  Tl  Tl8  1  0.807  0.671  0.741  1.0
  Tl  Tl9  1  0.000  0.500  0.500  1.0
  Tl  Tl10  1  0.764  0.236  0.750  1.0
  Tl  Tl11  1  0.671  0.807  0.241  1.0
  Tl  Tl12  1  0.500  0.000  0.000  1.0
  Tl  Tl13  1  0.329  0.193  0.759  1.0
  Tl  Tl14  1  0.236  0.764  0.250  1.0
  Tl  Tl15  1  0.193  0.329  0.259  1.0
  O  O16  1  0.099  0.590  0.845  1.0
  O  O17  1  0.780  0.911  0.529  1.0
  O  O18  1  0.407  0.279  0.534  1.0
  O  O19  1  0.463  0.594  0.846  1.0
  O  O20  1  0.720  0.220  0.970  1.0
  O  O21  1  0.590  0.099  0.345  1.0
  O  O22  1  0.279  0.407  0.034  1.0
  O  O23  1  0.406  0.537  0.654  1.0
  O  O24  1  0.098  0.970  0.843  1.0
  O  O25  1  0.780  0.280  0.530  1.0
  O  O26  1  0.911  0.780  0.029  1.0
  O  O27  1  0.030  0.902  0.657  1.0
  O  O28  1  0.089  0.220  0.971  1.0
  O  O29  1  0.970  0.098  0.343  1.0
  O  O30  1  0.220  0.720  0.470  1.0
  O  O31  1  0.902  0.030  0.157  1.0
  O  O32  1  0.594  0.463  0.346  1.0
  O  O33  1  0.721  0.593  0.966  1.0
  O  O34  1  0.280  0.780  0.030  1.0
  O  O35  1  0.410  0.901  0.655  1.0
  O  O36  1  0.537  0.406  0.154  1.0
  O  O37  1  0.593  0.721  0.466  1.0
  O  O38  1  0.220  0.089  0.471  1.0
  O  O39  1  0.901  0.410  0.155  1.0
[/CIF]
.