The structure described by FeOOH crystallizes in the monoclinic C2/m space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), two equivalent O(4), and three equivalent O(1) atoms to form a mixture of distorted edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 53-54°. In the second Fe site, Fe(2) is bonded to one O(4), two equivalent O(3), and three equivalent O(2) atoms to form a mixture of distorted edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 53-54°. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(2) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to three equivalent Fe(1) and one H(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to three equivalent Fe(2) and one H(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(1) and two equivalent Fe(2) atoms. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(1) atoms. is represented by the CIF file [CIF]
data_FeHO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.078
_cell_length_b   7.723
_cell_length_c   7.639
_cell_angle_alpha   92.993
_cell_angle_beta   101.625
_cell_angle_gamma   78.505
_symmetry_Int_Tables_number   1
_cell_volume   174.295
_cell_formula_units_Z   4
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
  Fe  Fe0  1  0.355  0.495  0.206  1.0
  Fe  Fe1  1  0.149  0.205  0.502  1.0
  Fe  Fe2  1  0.645  0.505  0.794  1.0
  Fe  Fe3  1  0.851  0.795  0.498  1.0
  H  H4  1  0.909  0.244  0.061  1.0
  H  H5  1  0.091  0.756  0.939  1.0
  H  H6  1  0.846  0.066  0.759  1.0
  H  H7  1  0.154  0.934  0.241  1.0
  O  O8  1  0.837  0.371  0.046  1.0
  O  O9  1  0.163  0.629  0.954  1.0
  O  O10  1  0.789  0.053  0.630  1.0
  O  O11  1  0.211  0.947  0.370  1.0
  O  O12  1  0.464  0.710  0.638  1.0
  O  O13  1  0.536  0.290  0.362  1.0
  O  O14  1  0.836  0.628  0.300  1.0
  O  O15  1  0.164  0.372  0.700  1.0
[/CIF]
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The structure described by FeOOH crystallizes in the monoclinic C2/m space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), two equivalent O(4), and three equivalent O(1) atoms to form a mixture of distorted edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 53-54°. In the second Fe site, Fe(2) is bonded to one O(4), two equivalent O(3), and three equivalent O(2) atoms to form a mixture of distorted edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 53-54°. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(2) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to three equivalent Fe(1) and one H(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to three equivalent Fe(2) and one H(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(1) and two equivalent Fe(2) atoms. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(1) atoms. is represented by the CIF file [CIF]
data_FeHO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.078
_cell_length_b   7.723
_cell_length_c   7.639
_cell_angle_alpha   92.993
_cell_angle_beta   101.625
_cell_angle_gamma   78.505
_symmetry_Int_Tables_number   1
_cell_volume   174.295
_cell_formula_units_Z   4
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
  Fe  Fe0  1  0.355  0.495  0.206  1.0
  Fe  Fe1  1  0.149  0.205  0.502  1.0
  Fe  Fe2  1  0.645  0.505  0.794  1.0
  Fe  Fe3  1  0.851  0.795  0.498  1.0
  H  H4  1  0.909  0.244  0.061  1.0
  H  H5  1  0.091  0.756  0.939  1.0
  H  H6  1  0.846  0.066  0.759  1.0
  H  H7  1  0.154  0.934  0.241  1.0
  O  O8  1  0.837  0.371  0.046  1.0
  O  O9  1  0.163  0.629  0.954  1.0
  O  O10  1  0.789  0.053  0.630  1.0
  O  O11  1  0.211  0.947  0.370  1.0
  O  O12  1  0.464  0.710  0.638  1.0
  O  O13  1  0.536  0.290  0.362  1.0
  O  O14  1  0.836  0.628  0.300  1.0
  O  O15  1  0.164  0.372  0.700  1.0
[/CIF]
.