The crystal structure described by La3TaO7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. In the second La site, La(2) is bonded to one O(3), two equivalent O(1), and four equivalent O(2) atoms to form distorted LaO7 pentagonal bipyramids that share corners with two equivalent Ta(1)O6 octahedra, corners with three equivalent La(2)O7 pentagonal bipyramids, edges with two equivalent Ta(1)O6 octahedra, and edges with two equivalent La(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 39°. Ta(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent La(2)O7 pentagonal bipyramids, and edges with four equivalent La(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 27°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent La(1) and two equivalent La(2) atoms to form a mixture of corner and edge-sharing OLa4 tetrahedra. In the second O site, O(2) is bonded in a 4-coordinate geometry to one La(1), two equivalent La(2), and one Ta(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent La(2) and two equivalent Ta(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_La3TaO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.755
_cell_length_b   6.755
_cell_length_c   7.778
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   111.754
_symmetry_Int_Tables_number   1
_cell_volume   329.614
_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
  La  La0  1  0.000  0.000  0.000  1.0
  La  La1  1  0.000  0.000  0.500  1.0
  La  La2  1  0.476  0.931  0.750  1.0
  La  La3  1  0.524  0.069  0.250  1.0
  La  La4  1  0.931  0.476  0.750  1.0
  La  La5  1  0.069  0.524  0.250  1.0
  Ta  Ta6  1  0.500  0.500  0.000  1.0
  Ta  Ta7  1  0.500  0.500  0.500  1.0
  O  O8  1  0.846  0.106  0.750  1.0
  O  O9  1  0.154  0.894  0.250  1.0
  O  O10  1  0.106  0.846  0.750  1.0
  O  O11  1  0.894  0.154  0.250  1.0
  O  O12  1  0.439  0.190  0.967  1.0
  O  O13  1  0.561  0.810  0.467  1.0
  O  O14  1  0.190  0.439  0.533  1.0
  O  O15  1  0.810  0.561  0.033  1.0
  O  O16  1  0.438  0.438  0.250  1.0
  O  O17  1  0.562  0.562  0.750  1.0
  O  O18  1  0.190  0.439  0.967  1.0
  O  O19  1  0.810  0.561  0.467  1.0
  O  O20  1  0.439  0.190  0.533  1.0
  O  O21  1  0.561  0.810  0.033  1.0
[/CIF]
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The crystal structure described by La3TaO7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. In the second La site, La(2) is bonded to one O(3), two equivalent O(1), and four equivalent O(2) atoms to form distorted LaO7 pentagonal bipyramids that share corners with two equivalent Ta(1)O6 octahedra, corners with three equivalent La(2)O7 pentagonal bipyramids, edges with two equivalent Ta(1)O6 octahedra, and edges with two equivalent La(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 39°. Ta(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent La(2)O7 pentagonal bipyramids, and edges with four equivalent La(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 27°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent La(1) and two equivalent La(2) atoms to form a mixture of corner and edge-sharing OLa4 tetrahedra. In the second O site, O(2) is bonded in a 4-coordinate geometry to one La(1), two equivalent La(2), and one Ta(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent La(2) and two equivalent Ta(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_La3TaO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.755
_cell_length_b   6.755
_cell_length_c   7.778
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   111.754
_symmetry_Int_Tables_number   1
_cell_volume   329.614
_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
  La  La0  1  0.000  0.000  0.000  1.0
  La  La1  1  0.000  0.000  0.500  1.0
  La  La2  1  0.476  0.931  0.750  1.0
  La  La3  1  0.524  0.069  0.250  1.0
  La  La4  1  0.931  0.476  0.750  1.0
  La  La5  1  0.069  0.524  0.250  1.0
  Ta  Ta6  1  0.500  0.500  0.000  1.0
  Ta  Ta7  1  0.500  0.500  0.500  1.0
  O  O8  1  0.846  0.106  0.750  1.0
  O  O9  1  0.154  0.894  0.250  1.0
  O  O10  1  0.106  0.846  0.750  1.0
  O  O11  1  0.894  0.154  0.250  1.0
  O  O12  1  0.439  0.190  0.967  1.0
  O  O13  1  0.561  0.810  0.467  1.0
  O  O14  1  0.190  0.439  0.533  1.0
  O  O15  1  0.810  0.561  0.033  1.0
  O  O16  1  0.438  0.438  0.250  1.0
  O  O17  1  0.562  0.562  0.750  1.0
  O  O18  1  0.190  0.439  0.967  1.0
  O  O19  1  0.810  0.561  0.467  1.0
  O  O20  1  0.439  0.190  0.533  1.0
  O  O21  1  0.561  0.810  0.033  1.0
[/CIF]
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