The material structure described by Nd2W2O9 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 9-coordinate geometry to one O(2), one O(3), one O(7), one O(8), one O(9), two equivalent O(1), and two equivalent O(4) atoms. In the second Nd site, Nd(2) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(6), one O(7), one O(8), and two equivalent O(5) atoms. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(1), one O(2), one O(5), one O(6), one O(7), and one O(9) atom to form a mixture of distorted edge and corner-sharing WO6 octahedra. The corner-sharing octahedral tilt angles are 43°. In the second W site, W(2) is bonded to one O(2), one O(3), one O(4), one O(6), one O(8), and one O(9) atom to form a mixture of distorted edge and corner-sharing WO6 octahedra. The corner-sharing octahedral tilt angles are 43°. There are nine inequivalent O sites. In the first O site, O(8) is bonded in a 3-coordinate geometry to one Nd(1), one Nd(2), and one W(2) atom. In the second O site, O(9) is bonded in a distorted trigonal planar geometry to one Nd(1), one W(1), and one W(2) atom. In the third O site, O(1) is bonded in a 3-coordinate geometry to one Nd(2), two equivalent Nd(1), and one W(1) atom. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to one Nd(1), one Nd(2), one W(1), and one W(2) atom. In the fifth O site, O(3) is bonded in a 3-coordinate geometry to one Nd(1), one Nd(2), and one W(2) atom. In the sixth O site, O(4) is bonded to one Nd(2), two equivalent Nd(1), and one W(2) atom to form edge-sharing ONd3W tetrahedra. In the seventh O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Nd(2) and one W(1) atom. In the eighth O site, O(6) is bonded in a 3-coordinate geometry to one Nd(2), one W(1), and one W(2) atom. In the ninth O site, O(7) is bonded in a 3-coordinate geometry to one Nd(1), one Nd(2), and one W(1) atom. is represented by the CIF file [CIF]
data_Nd2W2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.885
_cell_length_b   7.671
_cell_length_c   9.265
_cell_angle_alpha   72.550
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   670.200
_cell_formula_units_Z   4
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  0.453  0.283  0.427  1.0
  Nd  Nd1  1  0.047  0.283  0.927  1.0
  Nd  Nd2  1  0.553  0.772  0.153  1.0
  Nd  Nd3  1  0.053  0.228  0.347  1.0
  Nd  Nd4  1  0.947  0.772  0.653  1.0
  Nd  Nd5  1  0.447  0.228  0.847  1.0
  Nd  Nd6  1  0.953  0.717  0.073  1.0
  Nd  Nd7  1  0.547  0.717  0.573  1.0
  W  W8  1  0.248  0.930  0.738  1.0
  W  W9  1  0.726  0.425  0.964  1.0
  W  W10  1  0.752  0.070  0.262  1.0
  W  W11  1  0.774  0.425  0.464  1.0
  W  W12  1  0.252  0.930  0.238  1.0
  W  W13  1  0.748  0.070  0.762  1.0
  W  W14  1  0.274  0.575  0.036  1.0
  W  W15  1  0.226  0.575  0.536  1.0
  O  O16  1  0.591  0.952  0.342  1.0
  O  O17  1  0.635  0.263  0.641  1.0
  O  O18  1  0.135  0.737  0.859  1.0
  O  O19  1  0.709  0.588  0.072  1.0
  O  O20  1  0.395  0.446  0.607  1.0
  O  O21  1  0.291  0.412  0.928  1.0
  O  O22  1  0.620  0.989  0.905  1.0
  O  O23  1  0.622  0.228  0.078  1.0
  O  O24  1  0.218  0.100  0.839  1.0
  O  O25  1  0.282  0.100  0.339  1.0
  O  O26  1  0.605  0.554  0.393  1.0
  O  O27  1  0.105  0.446  0.107  1.0
  O  O28  1  0.878  0.228  0.578  1.0
  O  O29  1  0.091  0.048  0.158  1.0
  O  O30  1  0.409  0.048  0.658  1.0
  O  O31  1  0.122  0.772  0.422  1.0
  O  O32  1  0.404  0.494  0.177  1.0
  O  O33  1  0.378  0.772  0.922  1.0
  O  O34  1  0.096  0.494  0.677  1.0
  O  O35  1  0.596  0.506  0.823  1.0
  O  O36  1  0.120  0.011  0.595  1.0
  O  O37  1  0.909  0.952  0.842  1.0
  O  O38  1  0.689  0.258  0.360  1.0
  O  O39  1  0.209  0.412  0.428  1.0
  O  O40  1  0.865  0.263  0.141  1.0
  O  O41  1  0.365  0.737  0.359  1.0
  O  O42  1  0.311  0.742  0.640  1.0
  O  O43  1  0.904  0.506  0.323  1.0
  O  O44  1  0.811  0.258  0.860  1.0
  O  O45  1  0.895  0.554  0.893  1.0
  O  O46  1  0.791  0.588  0.572  1.0
  O  O47  1  0.880  0.989  0.405  1.0
  O  O48  1  0.718  0.900  0.661  1.0
  O  O49  1  0.380  0.011  0.095  1.0
  O  O50  1  0.782  0.900  0.161  1.0
  O  O51  1  0.189  0.742  0.140  1.0
[/CIF]
.
The material structure described by Nd2W2O9 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 9-coordinate geometry to one O(2), one O(3), one O(7), one O(8), one O(9), two equivalent O(1), and two equivalent O(4) atoms. In the second Nd site, Nd(2) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(6), one O(7), one O(8), and two equivalent O(5) atoms. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(1), one O(2), one O(5), one O(6), one O(7), and one O(9) atom to form a mixture of distorted edge and corner-sharing WO6 octahedra. The corner-sharing octahedral tilt angles are 43°. In the second W site, W(2) is bonded to one O(2), one O(3), one O(4), one O(6), one O(8), and one O(9) atom to form a mixture of distorted edge and corner-sharing WO6 octahedra. The corner-sharing octahedral tilt angles are 43°. There are nine inequivalent O sites. In the first O site, O(8) is bonded in a 3-coordinate geometry to one Nd(1), one Nd(2), and one W(2) atom. In the second O site, O(9) is bonded in a distorted trigonal planar geometry to one Nd(1), one W(1), and one W(2) atom. In the third O site, O(1) is bonded in a 3-coordinate geometry to one Nd(2), two equivalent Nd(1), and one W(1) atom. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to one Nd(1), one Nd(2), one W(1), and one W(2) atom. In the fifth O site, O(3) is bonded in a 3-coordinate geometry to one Nd(1), one Nd(2), and one W(2) atom. In the sixth O site, O(4) is bonded to one Nd(2), two equivalent Nd(1), and one W(2) atom to form edge-sharing ONd3W tetrahedra. In the seventh O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Nd(2) and one W(1) atom. In the eighth O site, O(6) is bonded in a 3-coordinate geometry to one Nd(2), one W(1), and one W(2) atom. In the ninth O site, O(7) is bonded in a 3-coordinate geometry to one Nd(1), one Nd(2), and one W(1) atom. is represented by the CIF file [CIF]
data_Nd2W2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.885
_cell_length_b   7.671
_cell_length_c   9.265
_cell_angle_alpha   72.550
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   670.200
_cell_formula_units_Z   4
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  0.453  0.283  0.427  1.0
  Nd  Nd1  1  0.047  0.283  0.927  1.0
  Nd  Nd2  1  0.553  0.772  0.153  1.0
  Nd  Nd3  1  0.053  0.228  0.347  1.0
  Nd  Nd4  1  0.947  0.772  0.653  1.0
  Nd  Nd5  1  0.447  0.228  0.847  1.0
  Nd  Nd6  1  0.953  0.717  0.073  1.0
  Nd  Nd7  1  0.547  0.717  0.573  1.0
  W  W8  1  0.248  0.930  0.738  1.0
  W  W9  1  0.726  0.425  0.964  1.0
  W  W10  1  0.752  0.070  0.262  1.0
  W  W11  1  0.774  0.425  0.464  1.0
  W  W12  1  0.252  0.930  0.238  1.0
  W  W13  1  0.748  0.070  0.762  1.0
  W  W14  1  0.274  0.575  0.036  1.0
  W  W15  1  0.226  0.575  0.536  1.0
  O  O16  1  0.591  0.952  0.342  1.0
  O  O17  1  0.635  0.263  0.641  1.0
  O  O18  1  0.135  0.737  0.859  1.0
  O  O19  1  0.709  0.588  0.072  1.0
  O  O20  1  0.395  0.446  0.607  1.0
  O  O21  1  0.291  0.412  0.928  1.0
  O  O22  1  0.620  0.989  0.905  1.0
  O  O23  1  0.622  0.228  0.078  1.0
  O  O24  1  0.218  0.100  0.839  1.0
  O  O25  1  0.282  0.100  0.339  1.0
  O  O26  1  0.605  0.554  0.393  1.0
  O  O27  1  0.105  0.446  0.107  1.0
  O  O28  1  0.878  0.228  0.578  1.0
  O  O29  1  0.091  0.048  0.158  1.0
  O  O30  1  0.409  0.048  0.658  1.0
  O  O31  1  0.122  0.772  0.422  1.0
  O  O32  1  0.404  0.494  0.177  1.0
  O  O33  1  0.378  0.772  0.922  1.0
  O  O34  1  0.096  0.494  0.677  1.0
  O  O35  1  0.596  0.506  0.823  1.0
  O  O36  1  0.120  0.011  0.595  1.0
  O  O37  1  0.909  0.952  0.842  1.0
  O  O38  1  0.689  0.258  0.360  1.0
  O  O39  1  0.209  0.412  0.428  1.0
  O  O40  1  0.865  0.263  0.141  1.0
  O  O41  1  0.365  0.737  0.359  1.0
  O  O42  1  0.311  0.742  0.640  1.0
  O  O43  1  0.904  0.506  0.323  1.0
  O  O44  1  0.811  0.258  0.860  1.0
  O  O45  1  0.895  0.554  0.893  1.0
  O  O46  1  0.791  0.588  0.572  1.0
  O  O47  1  0.880  0.989  0.405  1.0
  O  O48  1  0.718  0.900  0.661  1.0
  O  O49  1  0.380  0.011  0.095  1.0
  O  O50  1  0.782  0.900  0.161  1.0
  O  O51  1  0.189  0.742  0.140  1.0
[/CIF]
.