The crystal structure described by FeOOH crystallizes in the orthorhombic Pnma space group. Fe(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles are 56°. H(1) is bonded in a distorted linear geometry to one O(1) and one O(2) atom. There are two 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 to three equivalent Fe(1) and one H(1) atom to form a mixture of distorted corner and edge-sharing OFe3H tetrahedra. is represented by the CIF card [CIF]
data_FeHO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.084
_cell_length_b   4.606
_cell_length_c   10.153
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   144.212
_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  0.250  0.522  0.626  1.0
  Fe  Fe1  1  0.250  0.978  0.126  1.0
  Fe  Fe2  1  0.750  0.478  0.374  1.0
  Fe  Fe3  1  0.750  0.022  0.874  1.0
  H  H4  1  0.250  0.022  0.374  1.0
  H  H5  1  0.250  0.478  0.874  1.0
  H  H6  1  0.750  0.978  0.626  1.0
  H  H7  1  0.750  0.522  0.126  1.0
  O  O8  1  0.250  0.192  0.308  1.0
  O  O9  1  0.250  0.308  0.808  1.0
  O  O10  1  0.750  0.808  0.692  1.0
  O  O11  1  0.750  0.692  0.192  1.0
  O  O12  1  0.250  0.708  0.442  1.0
  O  O13  1  0.250  0.792  0.942  1.0
  O  O14  1  0.750  0.292  0.558  1.0
  O  O15  1  0.750  0.208  0.058  1.0
[/CIF]
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The crystal structure described by FeOOH crystallizes in the orthorhombic Pnma space group. Fe(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles are 56°. H(1) is bonded in a distorted linear geometry to one O(1) and one O(2) atom. There are two 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 to three equivalent Fe(1) and one H(1) atom to form a mixture of distorted corner and edge-sharing OFe3H tetrahedra. is represented by the CIF card [CIF]
data_FeHO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.084
_cell_length_b   4.606
_cell_length_c   10.153
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   144.212
_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  0.250  0.522  0.626  1.0
  Fe  Fe1  1  0.250  0.978  0.126  1.0
  Fe  Fe2  1  0.750  0.478  0.374  1.0
  Fe  Fe3  1  0.750  0.022  0.874  1.0
  H  H4  1  0.250  0.022  0.374  1.0
  H  H5  1  0.250  0.478  0.874  1.0
  H  H6  1  0.750  0.978  0.626  1.0
  H  H7  1  0.750  0.522  0.126  1.0
  O  O8  1  0.250  0.192  0.308  1.0
  O  O9  1  0.250  0.308  0.808  1.0
  O  O10  1  0.750  0.808  0.692  1.0
  O  O11  1  0.750  0.692  0.192  1.0
  O  O12  1  0.250  0.708  0.442  1.0
  O  O13  1  0.250  0.792  0.942  1.0
  O  O14  1  0.750  0.292  0.558  1.0
  O  O15  1  0.750  0.208  0.058  1.0
[/CIF]
.