The structure described by NaTaO3Ta2O5 crystallizes in the orthorhombic Ibam space group. Na(1) is bonded to four equivalent O(1) and four equivalent O(2) atoms to form distorted NaO8 hexagonal bipyramids that share edges with two equivalent Na(1)O8 hexagonal bipyramids, edges with two equivalent Ta(2)O8 hexagonal bipyramids, and edges with eight equivalent Ta(1)O7 pentagonal bipyramids. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(3), two equivalent O(2), and four equivalent O(1) atoms to form distorted TaO7 pentagonal bipyramids that share corners with two equivalent Ta(2)O8 hexagonal bipyramids, corners with two equivalent Ta(1)O7 pentagonal bipyramids, edges with two equivalent Ta(2)O8 hexagonal bipyramids, edges with four equivalent Na(1)O8 hexagonal bipyramids, and edges with two equivalent Ta(1)O7 pentagonal bipyramids. In the second Ta site, Ta(2) is bonded to four equivalent O(1) and four equivalent O(3) atoms to form distorted TaO8 hexagonal bipyramids that share corners with four equivalent Ta(1)O7 pentagonal bipyramids, edges with two equivalent Na(1)O8 hexagonal bipyramids, edges with two equivalent Ta(2)O8 hexagonal bipyramids, and edges with four equivalent Ta(1)O7 pentagonal bipyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Ta(2), and two equivalent Ta(1) atoms to form distorted ONaTa3 trigonal pyramids that share corners with four equivalent O(2)Na2Ta2 tetrahedra, corners with eight equivalent O(1)NaTa3 trigonal pyramids, edges with two equivalent O(2)Na2Ta2 tetrahedra, and edges with two equivalent O(1)NaTa3 trigonal pyramids. In the second O site, O(2) is bonded to two equivalent Na(1) and two equivalent Ta(1) atoms to form distorted ONa2Ta2 tetrahedra that share corners with six equivalent O(2)Na2Ta2 tetrahedra, corners with eight equivalent O(1)NaTa3 trigonal pyramids,  an edgeedge with one O(2)Na2Ta2 tetrahedra, and edges with four equivalent O(1)NaTa3 trigonal pyramids. In the third O site, O(3) is bonded in a trigonal planar geometry to one Ta(1) and two equivalent Ta(2) atoms. is represented by the CIF card [CIF]
data_NaTa3O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.320
_cell_length_b   7.320
_cell_length_c   7.320
_cell_angle_alpha   122.107
_cell_angle_beta   120.070
_cell_angle_gamma   88.134
_symmetry_Int_Tables_number   1
_cell_volume   272.501
_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
  Na  Na0  1  0.000  0.250  0.250  1.0
  Na  Na1  1  0.000  0.750  0.750  1.0
  Ta  Ta2  1  0.502  0.763  0.739  1.0
  Ta  Ta3  1  0.498  0.237  0.261  1.0
  Ta  Ta4  1  0.976  0.737  0.239  1.0
  Ta  Ta5  1  0.024  0.263  0.761  1.0
  Ta  Ta6  1  0.500  0.250  0.750  1.0
  Ta  Ta7  1  0.500  0.750  0.250  1.0
  O  O8  1  0.448  0.846  0.009  1.0
  O  O9  1  0.552  0.561  0.398  1.0
  O  O10  1  0.163  0.654  0.102  1.0
  O  O11  1  0.837  0.939  0.491  1.0
  O  O12  1  0.552  0.154  0.991  1.0
  O  O13  1  0.448  0.439  0.602  1.0
  O  O14  1  0.837  0.346  0.898  1.0
  O  O15  1  0.163  0.061  0.509  1.0
  O  O16  1  0.185  0.174  0.011  1.0
  O  O17  1  0.815  0.826  0.989  1.0
  O  O18  1  0.837  0.326  0.511  1.0
  O  O19  1  0.163  0.674  0.489  1.0
  O  O20  1  0.315  0.431  0.884  1.0
  O  O21  1  0.685  0.569  0.116  1.0
  O  O22  1  0.454  0.069  0.384  1.0
  O  O23  1  0.546  0.931  0.616  1.0
[/CIF]
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The structure described by NaTaO3Ta2O5 crystallizes in the orthorhombic Ibam space group. Na(1) is bonded to four equivalent O(1) and four equivalent O(2) atoms to form distorted NaO8 hexagonal bipyramids that share edges with two equivalent Na(1)O8 hexagonal bipyramids, edges with two equivalent Ta(2)O8 hexagonal bipyramids, and edges with eight equivalent Ta(1)O7 pentagonal bipyramids. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(3), two equivalent O(2), and four equivalent O(1) atoms to form distorted TaO7 pentagonal bipyramids that share corners with two equivalent Ta(2)O8 hexagonal bipyramids, corners with two equivalent Ta(1)O7 pentagonal bipyramids, edges with two equivalent Ta(2)O8 hexagonal bipyramids, edges with four equivalent Na(1)O8 hexagonal bipyramids, and edges with two equivalent Ta(1)O7 pentagonal bipyramids. In the second Ta site, Ta(2) is bonded to four equivalent O(1) and four equivalent O(3) atoms to form distorted TaO8 hexagonal bipyramids that share corners with four equivalent Ta(1)O7 pentagonal bipyramids, edges with two equivalent Na(1)O8 hexagonal bipyramids, edges with two equivalent Ta(2)O8 hexagonal bipyramids, and edges with four equivalent Ta(1)O7 pentagonal bipyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Ta(2), and two equivalent Ta(1) atoms to form distorted ONaTa3 trigonal pyramids that share corners with four equivalent O(2)Na2Ta2 tetrahedra, corners with eight equivalent O(1)NaTa3 trigonal pyramids, edges with two equivalent O(2)Na2Ta2 tetrahedra, and edges with two equivalent O(1)NaTa3 trigonal pyramids. In the second O site, O(2) is bonded to two equivalent Na(1) and two equivalent Ta(1) atoms to form distorted ONa2Ta2 tetrahedra that share corners with six equivalent O(2)Na2Ta2 tetrahedra, corners with eight equivalent O(1)NaTa3 trigonal pyramids,  an edgeedge with one O(2)Na2Ta2 tetrahedra, and edges with four equivalent O(1)NaTa3 trigonal pyramids. In the third O site, O(3) is bonded in a trigonal planar geometry to one Ta(1) and two equivalent Ta(2) atoms. is represented by the CIF card [CIF]
data_NaTa3O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.320
_cell_length_b   7.320
_cell_length_c   7.320
_cell_angle_alpha   122.107
_cell_angle_beta   120.070
_cell_angle_gamma   88.134
_symmetry_Int_Tables_number   1
_cell_volume   272.501
_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
  Na  Na0  1  0.000  0.250  0.250  1.0
  Na  Na1  1  0.000  0.750  0.750  1.0
  Ta  Ta2  1  0.502  0.763  0.739  1.0
  Ta  Ta3  1  0.498  0.237  0.261  1.0
  Ta  Ta4  1  0.976  0.737  0.239  1.0
  Ta  Ta5  1  0.024  0.263  0.761  1.0
  Ta  Ta6  1  0.500  0.250  0.750  1.0
  Ta  Ta7  1  0.500  0.750  0.250  1.0
  O  O8  1  0.448  0.846  0.009  1.0
  O  O9  1  0.552  0.561  0.398  1.0
  O  O10  1  0.163  0.654  0.102  1.0
  O  O11  1  0.837  0.939  0.491  1.0
  O  O12  1  0.552  0.154  0.991  1.0
  O  O13  1  0.448  0.439  0.602  1.0
  O  O14  1  0.837  0.346  0.898  1.0
  O  O15  1  0.163  0.061  0.509  1.0
  O  O16  1  0.185  0.174  0.011  1.0
  O  O17  1  0.815  0.826  0.989  1.0
  O  O18  1  0.837  0.326  0.511  1.0
  O  O19  1  0.163  0.674  0.489  1.0
  O  O20  1  0.315  0.431  0.884  1.0
  O  O21  1  0.685  0.569  0.116  1.0
  O  O22  1  0.454  0.069  0.384  1.0
  O  O23  1  0.546  0.931  0.616  1.0
[/CIF]
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