The material described by H4OTa2O6 crystallizes in the monoclinic Cc space group. The structure consists of four water molecules inside a HTaO3 framework. In the HTaO3 framework, there are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(2), one O(5), one O(6), and two equivalent O(3) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 33-49°. In the second Ta site, Ta(2) is bonded to one O(1), one O(2), one O(5), one O(6), and two equivalent O(4) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 33-49°. There are two inequivalent H sites. In the first H site, H(3) is bonded in a single-bond geometry to one O(6) atom. In the second H site, H(4) is bonded in a single-bond geometry to one O(3) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ta(1) and one Ta(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Ta(1) and one Ta(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Ta(1) and one H(4) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to two equivalent Ta(2) atoms. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Ta(1) and one Ta(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Ta(1), one Ta(2), and one H(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ta2H4O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.481
_cell_length_b   7.481
_cell_length_c   7.461
_cell_angle_alpha   61.078
_cell_angle_beta   61.078
_cell_angle_gamma   89.663
_symmetry_Int_Tables_number   1
_cell_volume   305.393
_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  0.500  0.017  0.492  1.0
  Ta  Ta1  1  0.508  0.512  0.497  1.0
  Ta  Ta2  1  0.017  0.500  0.992  1.0
  Ta  Ta3  1  0.512  0.508  0.997  1.0
  H  H4  1  0.952  0.240  0.630  1.0
  H  H5  1  0.809  0.086  0.913  1.0
  H  H6  1  0.666  0.933  0.765  1.0
  H  H7  1  0.081  0.930  0.754  1.0
  H  H8  1  0.240  0.952  0.130  1.0
  H  H9  1  0.086  0.809  0.413  1.0
  H  H10  1  0.930  0.081  0.254  1.0
  H  H11  1  0.933  0.666  0.265  1.0
  O  O12  1  0.565  0.821  0.395  1.0
  O  O13  1  0.217  0.481  0.095  1.0
  O  O14  1  0.185  0.845  0.741  1.0
  O  O15  1  0.581  0.466  0.741  1.0
  O  O16  1  0.209  0.463  0.740  1.0
  O  O17  1  0.589  0.845  0.745  1.0
  O  O18  1  0.481  0.217  0.595  1.0
  O  O19  1  0.821  0.565  0.895  1.0
  O  O20  1  0.845  0.185  0.241  1.0
  O  O21  1  0.466  0.581  0.241  1.0
  O  O22  1  0.845  0.589  0.245  1.0
  O  O23  1  0.463  0.209  0.240  1.0
  O  O24  1  0.889  0.089  0.762  1.0
  O  O25  1  0.089  0.889  0.262  1.0
[/CIF]
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The material described by H4OTa2O6 crystallizes in the monoclinic Cc space group. The structure consists of four water molecules inside a HTaO3 framework. In the HTaO3 framework, there are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(2), one O(5), one O(6), and two equivalent O(3) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 33-49°. In the second Ta site, Ta(2) is bonded to one O(1), one O(2), one O(5), one O(6), and two equivalent O(4) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 33-49°. There are two inequivalent H sites. In the first H site, H(3) is bonded in a single-bond geometry to one O(6) atom. In the second H site, H(4) is bonded in a single-bond geometry to one O(3) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Ta(1) and one Ta(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Ta(1) and one Ta(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Ta(1) and one H(4) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to two equivalent Ta(2) atoms. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Ta(1) and one Ta(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Ta(1), one Ta(2), and one H(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ta2H4O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.481
_cell_length_b   7.481
_cell_length_c   7.461
_cell_angle_alpha   61.078
_cell_angle_beta   61.078
_cell_angle_gamma   89.663
_symmetry_Int_Tables_number   1
_cell_volume   305.393
_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  0.500  0.017  0.492  1.0
  Ta  Ta1  1  0.508  0.512  0.497  1.0
  Ta  Ta2  1  0.017  0.500  0.992  1.0
  Ta  Ta3  1  0.512  0.508  0.997  1.0
  H  H4  1  0.952  0.240  0.630  1.0
  H  H5  1  0.809  0.086  0.913  1.0
  H  H6  1  0.666  0.933  0.765  1.0
  H  H7  1  0.081  0.930  0.754  1.0
  H  H8  1  0.240  0.952  0.130  1.0
  H  H9  1  0.086  0.809  0.413  1.0
  H  H10  1  0.930  0.081  0.254  1.0
  H  H11  1  0.933  0.666  0.265  1.0
  O  O12  1  0.565  0.821  0.395  1.0
  O  O13  1  0.217  0.481  0.095  1.0
  O  O14  1  0.185  0.845  0.741  1.0
  O  O15  1  0.581  0.466  0.741  1.0
  O  O16  1  0.209  0.463  0.740  1.0
  O  O17  1  0.589  0.845  0.745  1.0
  O  O18  1  0.481  0.217  0.595  1.0
  O  O19  1  0.821  0.565  0.895  1.0
  O  O20  1  0.845  0.185  0.241  1.0
  O  O21  1  0.466  0.581  0.241  1.0
  O  O22  1  0.845  0.589  0.245  1.0
  O  O23  1  0.463  0.209  0.240  1.0
  O  O24  1  0.889  0.089  0.762  1.0
  O  O25  1  0.089  0.889  0.262  1.0
[/CIF]
.