The structure described by Nd2Ta2O9 crystallizes in the monoclinic P2_1/c space group. Nd(1) is bonded in a 9-coordinate geometry to one O(4), two equivalent O(1), three equivalent O(2), and three equivalent O(5) atoms. Ta(1) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(4) atoms to form a mixture of distorted corner and edge-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 0-14°. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Nd(1) and two equivalent Ta(1) atoms to form a mixture of distorted corner and edge-sharing ONd2Ta2 trigonal pyramids. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to three equivalent Nd(1) atoms. In the third O site, O(3) is bonded in a linear geometry to two equivalent Ta(1) atoms. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Nd(1) and two equivalent Ta(1) atoms. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to three equivalent Nd(1) and one Ta(1) atom. is represented by the CIF file [CIF]
data_Nd2Ta2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.896
_cell_length_b   6.721
_cell_length_c   14.437
_cell_angle_alpha   93.143
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   377.470
_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  0.004  0.009  0.695  1.0
  Nd  Nd1  1  0.996  0.991  0.305  1.0
  Nd  Nd2  1  0.504  0.490  0.805  1.0
  Nd  Nd3  1  0.496  0.509  0.195  1.0
  Ta  Ta4  1  0.003  0.267  0.961  1.0
  Ta  Ta5  1  0.997  0.733  0.039  1.0
  Ta  Ta6  1  0.503  0.233  0.539  1.0
  Ta  Ta7  1  0.497  0.767  0.461  1.0
  O  O8  1  0.001  0.578  0.919  1.0
  O  O9  1  0.999  0.422  0.081  1.0
  O  O10  1  0.501  0.922  0.581  1.0
  O  O11  1  0.499  0.078  0.419  1.0
  O  O12  1  0.508  0.842  0.781  1.0
  O  O13  1  0.492  0.158  0.219  1.0
  O  O14  1  0.008  0.658  0.719  1.0
  O  O15  1  0.992  0.342  0.281  1.0
  O  O16  1  0.000  0.000  0.000  1.0
  O  O17  1  0.500  0.500  0.500  1.0
  O  O18  1  0.502  0.294  0.952  1.0
  O  O19  1  0.498  0.706  0.048  1.0
  O  O20  1  0.002  0.206  0.548  1.0
  O  O21  1  0.998  0.794  0.452  1.0
  O  O22  1  0.003  0.244  0.824  1.0
  O  O23  1  0.997  0.756  0.176  1.0
  O  O24  1  0.503  0.256  0.676  1.0
  O  O25  1  0.497  0.744  0.324  1.0
[/CIF]
.
The structure described by Nd2Ta2O9 crystallizes in the monoclinic P2_1/c space group. Nd(1) is bonded in a 9-coordinate geometry to one O(4), two equivalent O(1), three equivalent O(2), and three equivalent O(5) atoms. Ta(1) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(4) atoms to form a mixture of distorted corner and edge-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 0-14°. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Nd(1) and two equivalent Ta(1) atoms to form a mixture of distorted corner and edge-sharing ONd2Ta2 trigonal pyramids. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to three equivalent Nd(1) atoms. In the third O site, O(3) is bonded in a linear geometry to two equivalent Ta(1) atoms. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Nd(1) and two equivalent Ta(1) atoms. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to three equivalent Nd(1) and one Ta(1) atom. is represented by the CIF file [CIF]
data_Nd2Ta2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.896
_cell_length_b   6.721
_cell_length_c   14.437
_cell_angle_alpha   93.143
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   377.470
_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  0.004  0.009  0.695  1.0
  Nd  Nd1  1  0.996  0.991  0.305  1.0
  Nd  Nd2  1  0.504  0.490  0.805  1.0
  Nd  Nd3  1  0.496  0.509  0.195  1.0
  Ta  Ta4  1  0.003  0.267  0.961  1.0
  Ta  Ta5  1  0.997  0.733  0.039  1.0
  Ta  Ta6  1  0.503  0.233  0.539  1.0
  Ta  Ta7  1  0.497  0.767  0.461  1.0
  O  O8  1  0.001  0.578  0.919  1.0
  O  O9  1  0.999  0.422  0.081  1.0
  O  O10  1  0.501  0.922  0.581  1.0
  O  O11  1  0.499  0.078  0.419  1.0
  O  O12  1  0.508  0.842  0.781  1.0
  O  O13  1  0.492  0.158  0.219  1.0
  O  O14  1  0.008  0.658  0.719  1.0
  O  O15  1  0.992  0.342  0.281  1.0
  O  O16  1  0.000  0.000  0.000  1.0
  O  O17  1  0.500  0.500  0.500  1.0
  O  O18  1  0.502  0.294  0.952  1.0
  O  O19  1  0.498  0.706  0.048  1.0
  O  O20  1  0.002  0.206  0.548  1.0
  O  O21  1  0.998  0.794  0.452  1.0
  O  O22  1  0.003  0.244  0.824  1.0
  O  O23  1  0.997  0.756  0.176  1.0
  O  O24  1  0.503  0.256  0.676  1.0
  O  O25  1  0.497  0.744  0.324  1.0
[/CIF]
.