The crystal structure described by NdTa7O19 crystallizes in the hexagonal P6_322 space group. Nd(1) is bonded in a 8-coordinate geometry to two equivalent O(1) and six equivalent O(3) atoms. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(5), and two equivalent O(4) atoms. In the second Ta site, Ta(2) is bonded in an octahedral geometry to six equivalent O(3) atoms. There are five inequivalent O sites. In the first O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent Ta(1) atoms. In the second O site, O(1) is bonded in a 4-coordinate geometry to one Nd(1) and three equivalent Ta(1) atoms. In the third O site, O(2) is bonded in a trigonal planar geometry to three equivalent Ta(1) atoms. In the fourth O site, O(5) is bonded in a linear geometry to two equivalent Ta(1) atoms. In the fifth O site, O(3) is bonded in a distorted trigonal planar geometry to one Nd(1), one Ta(1), and one Ta(2) atom. is represented by the CIF card [CIF]
data_NdTa7O19
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.311
_cell_length_b   6.311
_cell_length_c   20.217
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   697.282
_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  0.333  0.667  0.750  1.0
  Nd  Nd1  1  0.667  0.333  0.250  1.0
  Ta  Ta2  1  0.359  0.355  0.594  1.0
  Ta  Ta3  1  0.645  0.004  0.594  1.0
  Ta  Ta4  1  0.996  0.641  0.594  1.0
  Ta  Ta5  1  0.645  0.641  0.906  1.0
  Ta  Ta6  1  0.359  0.004  0.906  1.0
  Ta  Ta7  1  0.996  0.355  0.906  1.0
  Ta  Ta8  1  0.641  0.645  0.094  1.0
  Ta  Ta9  1  0.355  0.996  0.094  1.0
  Ta  Ta10  1  0.004  0.359  0.094  1.0
  Ta  Ta11  1  0.355  0.359  0.406  1.0
  Ta  Ta12  1  0.641  0.996  0.406  1.0
  Ta  Ta13  1  0.004  0.645  0.406  1.0
  Ta  Ta14  1  0.667  0.333  0.750  1.0
  Ta  Ta15  1  0.333  0.667  0.250  1.0
  O  O16  1  0.333  0.667  0.613  1.0
  O  O17  1  0.667  0.333  0.589  1.0
  O  O18  1  0.667  0.333  0.911  1.0
  O  O19  1  0.333  0.667  0.887  1.0
  O  O20  1  0.667  0.333  0.113  1.0
  O  O21  1  0.333  0.667  0.089  1.0
  O  O22  1  0.333  0.667  0.411  1.0
  O  O23  1  0.667  0.333  0.387  1.0
  O  O24  1  0.383  0.432  0.306  1.0
  O  O25  1  0.568  0.951  0.306  1.0
  O  O26  1  0.049  0.617  0.306  1.0
  O  O27  1  0.568  0.617  0.194  1.0
  O  O28  1  0.383  0.951  0.194  1.0
  O  O29  1  0.049  0.432  0.194  1.0
  O  O30  1  0.617  0.568  0.806  1.0
  O  O31  1  0.432  0.049  0.806  1.0
  O  O32  1  0.951  0.383  0.806  1.0
  O  O33  1  0.432  0.383  0.694  1.0
  O  O34  1  0.617  0.049  0.694  1.0
  O  O35  1  0.951  0.568  0.694  1.0
  O  O36  1  0.003  0.244  0.597  1.0
  O  O37  1  0.756  0.759  0.597  1.0
  O  O38  1  0.241  0.997  0.597  1.0
  O  O39  1  0.003  0.759  0.903  1.0
  O  O40  1  0.241  0.244  0.903  1.0
  O  O41  1  0.756  0.997  0.903  1.0
  O  O42  1  0.997  0.756  0.097  1.0
  O  O43  1  0.244  0.241  0.097  1.0
  O  O44  1  0.759  0.003  0.097  1.0
  O  O45  1  0.997  0.241  0.403  1.0
  O  O46  1  0.759  0.756  0.403  1.0
  O  O47  1  0.244  0.003  0.403  1.0
  O  O48  1  0.394  0.394  0.500  1.0
  O  O49  1  0.606  0.000  0.500  1.0
  O  O50  1  0.000  0.606  0.500  1.0
  O  O51  1  0.606  0.606  0.000  1.0
  O  O52  1  0.394  0.000  0.000  1.0
  O  O53  1  0.000  0.394  0.000  1.0
[/CIF]
.
The crystal structure described by NdTa7O19 crystallizes in the hexagonal P6_322 space group. Nd(1) is bonded in a 8-coordinate geometry to two equivalent O(1) and six equivalent O(3) atoms. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(5), and two equivalent O(4) atoms. In the second Ta site, Ta(2) is bonded in an octahedral geometry to six equivalent O(3) atoms. There are five inequivalent O sites. In the first O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent Ta(1) atoms. In the second O site, O(1) is bonded in a 4-coordinate geometry to one Nd(1) and three equivalent Ta(1) atoms. In the third O site, O(2) is bonded in a trigonal planar geometry to three equivalent Ta(1) atoms. In the fourth O site, O(5) is bonded in a linear geometry to two equivalent Ta(1) atoms. In the fifth O site, O(3) is bonded in a distorted trigonal planar geometry to one Nd(1), one Ta(1), and one Ta(2) atom. is represented by the CIF card [CIF]
data_NdTa7O19
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.311
_cell_length_b   6.311
_cell_length_c   20.217
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   697.282
_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  0.333  0.667  0.750  1.0
  Nd  Nd1  1  0.667  0.333  0.250  1.0
  Ta  Ta2  1  0.359  0.355  0.594  1.0
  Ta  Ta3  1  0.645  0.004  0.594  1.0
  Ta  Ta4  1  0.996  0.641  0.594  1.0
  Ta  Ta5  1  0.645  0.641  0.906  1.0
  Ta  Ta6  1  0.359  0.004  0.906  1.0
  Ta  Ta7  1  0.996  0.355  0.906  1.0
  Ta  Ta8  1  0.641  0.645  0.094  1.0
  Ta  Ta9  1  0.355  0.996  0.094  1.0
  Ta  Ta10  1  0.004  0.359  0.094  1.0
  Ta  Ta11  1  0.355  0.359  0.406  1.0
  Ta  Ta12  1  0.641  0.996  0.406  1.0
  Ta  Ta13  1  0.004  0.645  0.406  1.0
  Ta  Ta14  1  0.667  0.333  0.750  1.0
  Ta  Ta15  1  0.333  0.667  0.250  1.0
  O  O16  1  0.333  0.667  0.613  1.0
  O  O17  1  0.667  0.333  0.589  1.0
  O  O18  1  0.667  0.333  0.911  1.0
  O  O19  1  0.333  0.667  0.887  1.0
  O  O20  1  0.667  0.333  0.113  1.0
  O  O21  1  0.333  0.667  0.089  1.0
  O  O22  1  0.333  0.667  0.411  1.0
  O  O23  1  0.667  0.333  0.387  1.0
  O  O24  1  0.383  0.432  0.306  1.0
  O  O25  1  0.568  0.951  0.306  1.0
  O  O26  1  0.049  0.617  0.306  1.0
  O  O27  1  0.568  0.617  0.194  1.0
  O  O28  1  0.383  0.951  0.194  1.0
  O  O29  1  0.049  0.432  0.194  1.0
  O  O30  1  0.617  0.568  0.806  1.0
  O  O31  1  0.432  0.049  0.806  1.0
  O  O32  1  0.951  0.383  0.806  1.0
  O  O33  1  0.432  0.383  0.694  1.0
  O  O34  1  0.617  0.049  0.694  1.0
  O  O35  1  0.951  0.568  0.694  1.0
  O  O36  1  0.003  0.244  0.597  1.0
  O  O37  1  0.756  0.759  0.597  1.0
  O  O38  1  0.241  0.997  0.597  1.0
  O  O39  1  0.003  0.759  0.903  1.0
  O  O40  1  0.241  0.244  0.903  1.0
  O  O41  1  0.756  0.997  0.903  1.0
  O  O42  1  0.997  0.756  0.097  1.0
  O  O43  1  0.244  0.241  0.097  1.0
  O  O44  1  0.759  0.003  0.097  1.0
  O  O45  1  0.997  0.241  0.403  1.0
  O  O46  1  0.759  0.756  0.403  1.0
  O  O47  1  0.244  0.003  0.403  1.0
  O  O48  1  0.394  0.394  0.500  1.0
  O  O49  1  0.606  0.000  0.500  1.0
  O  O50  1  0.000  0.606  0.500  1.0
  O  O51  1  0.606  0.606  0.000  1.0
  O  O52  1  0.394  0.000  0.000  1.0
  O  O53  1  0.000  0.394  0.000  1.0
[/CIF]
.