The structure described by H4OTa2O6 crystallizes in the orthorhombic Fddd space group. The structure consists of eight water molecules inside a HTaO3 framework. In the HTaO3 framework, Ta(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 32-47°. H(1) is bonded in a single-bond geometry to one O(3) atom. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Ta(1) atoms. In the second O site, O(2) is bonded in a bent 150 degrees geometry to two equivalent Ta(1) atoms. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Ta(1) and one H(1) atom. is represented by the CIF card [CIF]
data_Ta2H4O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.729
_cell_length_b   7.498
_cell_length_c   7.462
_cell_angle_alpha   62.216
_cell_angle_beta   59.118
_cell_angle_gamma   58.665
_symmetry_Int_Tables_number   1
_cell_volume   305.104
_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
  Ta  Ta0  1  0.125  0.625  0.625  1.0
  Ta  Ta1  1  0.625  0.125  0.625  1.0
  Ta  Ta2  1  0.625  0.625  0.125  1.0
  Ta  Ta3  1  0.625  0.625  0.625  1.0
  H  H4  1  0.804  0.196  0.196  1.0
  H  H5  1  0.196  0.804  0.804  1.0
  H  H6  1  0.446  0.054  0.054  1.0
  H  H7  1  0.054  0.446  0.446  1.0
  H  H8  1  0.912  0.088  0.912  1.0
  H  H9  1  0.088  0.912  0.088  1.0
  H  H10  1  0.162  0.338  0.162  1.0
  H  H11  1  0.338  0.162  0.338  1.0
  O  O12  1  0.327  0.327  0.673  1.0
  O  O13  1  0.673  0.673  0.327  1.0
  O  O14  1  0.321  0.679  0.321  1.0
  O  O15  1  0.679  0.321  0.679  1.0
  O  O16  1  0.707  0.293  0.293  1.0
  O  O17  1  0.293  0.707  0.707  1.0
  O  O18  1  0.923  0.923  0.577  1.0
  O  O19  1  0.577  0.577  0.923  1.0
  O  O20  1  0.929  0.571  0.929  1.0
  O  O21  1  0.571  0.929  0.571  1.0
  O  O22  1  0.543  0.957  0.957  1.0
  O  O23  1  0.957  0.543  0.543  1.0
  O  O24  1  0.000  0.000  0.000  1.0
  O  O25  1  0.250  0.250  0.250  1.0
[/CIF]
.
The structure described by H4OTa2O6 crystallizes in the orthorhombic Fddd space group. The structure consists of eight water molecules inside a HTaO3 framework. In the HTaO3 framework, Ta(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 32-47°. H(1) is bonded in a single-bond geometry to one O(3) atom. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Ta(1) atoms. In the second O site, O(2) is bonded in a bent 150 degrees geometry to two equivalent Ta(1) atoms. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Ta(1) and one H(1) atom. is represented by the CIF card [CIF]
data_Ta2H4O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.729
_cell_length_b   7.498
_cell_length_c   7.462
_cell_angle_alpha   62.216
_cell_angle_beta   59.118
_cell_angle_gamma   58.665
_symmetry_Int_Tables_number   1
_cell_volume   305.104
_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
  Ta  Ta0  1  0.125  0.625  0.625  1.0
  Ta  Ta1  1  0.625  0.125  0.625  1.0
  Ta  Ta2  1  0.625  0.625  0.125  1.0
  Ta  Ta3  1  0.625  0.625  0.625  1.0
  H  H4  1  0.804  0.196  0.196  1.0
  H  H5  1  0.196  0.804  0.804  1.0
  H  H6  1  0.446  0.054  0.054  1.0
  H  H7  1  0.054  0.446  0.446  1.0
  H  H8  1  0.912  0.088  0.912  1.0
  H  H9  1  0.088  0.912  0.088  1.0
  H  H10  1  0.162  0.338  0.162  1.0
  H  H11  1  0.338  0.162  0.338  1.0
  O  O12  1  0.327  0.327  0.673  1.0
  O  O13  1  0.673  0.673  0.327  1.0
  O  O14  1  0.321  0.679  0.321  1.0
  O  O15  1  0.679  0.321  0.679  1.0
  O  O16  1  0.707  0.293  0.293  1.0
  O  O17  1  0.293  0.707  0.707  1.0
  O  O18  1  0.923  0.923  0.577  1.0
  O  O19  1  0.577  0.577  0.923  1.0
  O  O20  1  0.929  0.571  0.929  1.0
  O  O21  1  0.571  0.929  0.571  1.0
  O  O22  1  0.543  0.957  0.957  1.0
  O  O23  1  0.957  0.543  0.543  1.0
  O  O24  1  0.000  0.000  0.000  1.0
  O  O25  1  0.250  0.250  0.250  1.0
[/CIF]
.