The structure described by H2W2O7 crystallizes in the orthorhombic Fdd2 space group. The structure consists of eight water molecules inside a WO3 framework. In the WO3 framework, W(1) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedral tilt angles range from 35-37°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent W(1) atoms. In the second O site, O(2) is bonded in a bent 150 degrees geometry to two equivalent W(1) atoms. In the third O site, O(3) is bonded in a bent 150 degrees geometry to two equivalent W(1) atoms. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to two equivalent W(1) atoms. is represented by the CIF card [CIF]
data_H2W2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.373
_cell_length_b   7.371
_cell_length_c   7.371
_cell_angle_alpha   60.020
_cell_angle_beta   59.995
_cell_angle_gamma   59.985
_symmetry_Int_Tables_number   1
_cell_volume   283.262
_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
  H  H0  1  0.817  0.778  0.836  1.0
  H  H1  1  0.836  0.569  0.817  1.0
  H  H2  1  0.681  0.414  0.472  1.0
  H  H3  1  0.472  0.433  0.681  1.0
  W  W4  1  0.249  0.001  0.748  1.0
  W  W5  1  0.249  0.502  0.249  1.0
  W  W6  1  0.748  0.001  0.249  1.0
  W  W7  1  0.249  0.001  0.249  1.0
  O  O8  1  0.942  0.058  0.308  1.0
  O  O9  1  0.308  0.692  0.942  1.0
  O  O10  1  0.309  0.691  0.309  1.0
  O  O11  1  0.943  0.057  0.943  1.0
  O  O12  1  0.308  0.057  0.943  1.0
  O  O13  1  0.943  0.692  0.308  1.0
  O  O14  1  0.558  0.942  0.192  1.0
  O  O15  1  0.192  0.308  0.558  1.0
  O  O16  1  0.193  0.307  0.193  1.0
  O  O17  1  0.559  0.941  0.559  1.0
  O  O18  1  0.193  0.942  0.558  1.0
  O  O19  1  0.558  0.307  0.193  1.0
  O  O20  1  0.883  0.617  0.883  1.0
  O  O21  1  0.633  0.367  0.633  1.0
[/CIF]
.
The structure described by H2W2O7 crystallizes in the orthorhombic Fdd2 space group. The structure consists of eight water molecules inside a WO3 framework. In the WO3 framework, W(1) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedral tilt angles range from 35-37°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent W(1) atoms. In the second O site, O(2) is bonded in a bent 150 degrees geometry to two equivalent W(1) atoms. In the third O site, O(3) is bonded in a bent 150 degrees geometry to two equivalent W(1) atoms. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to two equivalent W(1) atoms. is represented by the CIF card [CIF]
data_H2W2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.373
_cell_length_b   7.371
_cell_length_c   7.371
_cell_angle_alpha   60.020
_cell_angle_beta   59.995
_cell_angle_gamma   59.985
_symmetry_Int_Tables_number   1
_cell_volume   283.262
_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
  H  H0  1  0.817  0.778  0.836  1.0
  H  H1  1  0.836  0.569  0.817  1.0
  H  H2  1  0.681  0.414  0.472  1.0
  H  H3  1  0.472  0.433  0.681  1.0
  W  W4  1  0.249  0.001  0.748  1.0
  W  W5  1  0.249  0.502  0.249  1.0
  W  W6  1  0.748  0.001  0.249  1.0
  W  W7  1  0.249  0.001  0.249  1.0
  O  O8  1  0.942  0.058  0.308  1.0
  O  O9  1  0.308  0.692  0.942  1.0
  O  O10  1  0.309  0.691  0.309  1.0
  O  O11  1  0.943  0.057  0.943  1.0
  O  O12  1  0.308  0.057  0.943  1.0
  O  O13  1  0.943  0.692  0.308  1.0
  O  O14  1  0.558  0.942  0.192  1.0
  O  O15  1  0.192  0.308  0.558  1.0
  O  O16  1  0.193  0.307  0.193  1.0
  O  O17  1  0.559  0.941  0.559  1.0
  O  O18  1  0.193  0.942  0.558  1.0
  O  O19  1  0.558  0.307  0.193  1.0
  O  O20  1  0.883  0.617  0.883  1.0
  O  O21  1  0.633  0.367  0.633  1.0
[/CIF]
.