The crystal structure described by Nd3TaO7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a body-centered cubic geometry to four equivalent O(2) and four equivalent O(3) atoms. In the second Nd site, Nd(2) is bonded to one O(1), two equivalent O(3), and four equivalent O(2) atoms to form distorted NdO7 pentagonal bipyramids that share corners with two equivalent Ta(1)O6 octahedra, corners with three equivalent Nd(2)O7 pentagonal bipyramids, edges with two equivalent Ta(1)O6 octahedra, and edges with two equivalent Nd(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 38°. Ta(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent Nd(2)O7 pentagonal bipyramids, and edges with four equivalent Nd(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 30°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent Nd(2) and two equivalent Ta(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Nd(1), two equivalent Nd(2), and one Ta(1) atom. In the third O site, O(3) is bonded to two equivalent Nd(1) and two equivalent Nd(2) atoms to form a mixture of corner and edge-sharing ONd4 tetrahedra. is represented by the CIF file [CIF]
data_Nd3TaO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.643
_cell_length_b   6.643
_cell_length_c   7.675
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   111.262
_symmetry_Int_Tables_number   1
_cell_volume   315.668
_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
  Nd  Nd0  1  0.000  0.000  0.500  1.0
  Nd  Nd1  1  0.000  0.000  0.000  1.0
  Nd  Nd2  1  0.522  0.069  0.250  1.0
  Nd  Nd3  1  0.931  0.478  0.750  1.0
  Nd  Nd4  1  0.478  0.931  0.750  1.0
  Nd  Nd5  1  0.069  0.522  0.250  1.0
  Ta  Ta6  1  0.500  0.500  0.500  1.0
  Ta  Ta7  1  0.500  0.500  0.000  1.0
  O  O8  1  0.431  0.431  0.250  1.0
  O  O9  1  0.569  0.569  0.750  1.0
  O  O10  1  0.439  0.186  0.535  1.0
  O  O11  1  0.814  0.561  0.465  1.0
  O  O12  1  0.439  0.186  0.965  1.0
  O  O13  1  0.814  0.561  0.035  1.0
  O  O14  1  0.561  0.814  0.465  1.0
  O  O15  1  0.186  0.439  0.535  1.0
  O  O16  1  0.561  0.814  0.035  1.0
  O  O17  1  0.186  0.439  0.965  1.0
  O  O18  1  0.154  0.892  0.250  1.0
  O  O19  1  0.108  0.846  0.750  1.0
  O  O20  1  0.846  0.108  0.750  1.0
  O  O21  1  0.892  0.154  0.250  1.0
[/CIF]
.
The crystal structure described by Nd3TaO7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a body-centered cubic geometry to four equivalent O(2) and four equivalent O(3) atoms. In the second Nd site, Nd(2) is bonded to one O(1), two equivalent O(3), and four equivalent O(2) atoms to form distorted NdO7 pentagonal bipyramids that share corners with two equivalent Ta(1)O6 octahedra, corners with three equivalent Nd(2)O7 pentagonal bipyramids, edges with two equivalent Ta(1)O6 octahedra, and edges with two equivalent Nd(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 38°. Ta(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent Nd(2)O7 pentagonal bipyramids, and edges with four equivalent Nd(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 30°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent Nd(2) and two equivalent Ta(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Nd(1), two equivalent Nd(2), and one Ta(1) atom. In the third O site, O(3) is bonded to two equivalent Nd(1) and two equivalent Nd(2) atoms to form a mixture of corner and edge-sharing ONd4 tetrahedra. is represented by the CIF file [CIF]
data_Nd3TaO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.643
_cell_length_b   6.643
_cell_length_c   7.675
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   111.262
_symmetry_Int_Tables_number   1
_cell_volume   315.668
_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
  Nd  Nd0  1  0.000  0.000  0.500  1.0
  Nd  Nd1  1  0.000  0.000  0.000  1.0
  Nd  Nd2  1  0.522  0.069  0.250  1.0
  Nd  Nd3  1  0.931  0.478  0.750  1.0
  Nd  Nd4  1  0.478  0.931  0.750  1.0
  Nd  Nd5  1  0.069  0.522  0.250  1.0
  Ta  Ta6  1  0.500  0.500  0.500  1.0
  Ta  Ta7  1  0.500  0.500  0.000  1.0
  O  O8  1  0.431  0.431  0.250  1.0
  O  O9  1  0.569  0.569  0.750  1.0
  O  O10  1  0.439  0.186  0.535  1.0
  O  O11  1  0.814  0.561  0.465  1.0
  O  O12  1  0.439  0.186  0.965  1.0
  O  O13  1  0.814  0.561  0.035  1.0
  O  O14  1  0.561  0.814  0.465  1.0
  O  O15  1  0.186  0.439  0.535  1.0
  O  O16  1  0.561  0.814  0.035  1.0
  O  O17  1  0.186  0.439  0.965  1.0
  O  O18  1  0.154  0.892  0.250  1.0
  O  O19  1  0.108  0.846  0.750  1.0
  O  O20  1  0.846  0.108  0.750  1.0
  O  O21  1  0.892  0.154  0.250  1.0
[/CIF]
.