The material structure described by FeO2 crystallizes in the orthorhombic Imma space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-55°. In the second Fe site, Fe(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form FeO6 octahedra that share corners with six equivalent Fe(1)O4 tetrahedra and edges with two equivalent Fe(2)O6 octahedra. There are two inequivalent O sites. In the first O site, O(2) is bonded in a trigonal planar geometry to one Fe(1) and two equivalent Fe(2) atoms. In the second O site, O(1) is bonded in a bent 120 degrees geometry to one Fe(1) and one Fe(2) atom. is represented by the CIF card [CIF]
data_FeO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.754
_cell_length_b   5.754
_cell_length_c   5.754
_cell_angle_alpha   117.352
_cell_angle_beta   115.025
_cell_angle_gamma   96.750
_symmetry_Int_Tables_number   1
_cell_volume   141.310
_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  0.640  0.890  0.750  1.0
  Fe  Fe1  1  0.000  0.500  0.500  1.0
  Fe  Fe2  1  0.500  0.500  0.000  1.0
  Fe  Fe3  1  0.360  0.110  0.250  1.0
  O  O4  1  0.262  0.749  0.514  1.0
  O  O5  1  0.735  0.749  0.986  1.0
  O  O6  1  0.754  0.724  0.471  1.0
  O  O7  1  0.754  0.283  0.029  1.0
  O  O8  1  0.246  0.717  0.971  1.0
  O  O9  1  0.246  0.276  0.529  1.0
  O  O10  1  0.265  0.251  0.014  1.0
  O  O11  1  0.738  0.251  0.486  1.0
[/CIF]
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The material structure described by FeO2 crystallizes in the orthorhombic Imma space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-55°. In the second Fe site, Fe(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form FeO6 octahedra that share corners with six equivalent Fe(1)O4 tetrahedra and edges with two equivalent Fe(2)O6 octahedra. There are two inequivalent O sites. In the first O site, O(2) is bonded in a trigonal planar geometry to one Fe(1) and two equivalent Fe(2) atoms. In the second O site, O(1) is bonded in a bent 120 degrees geometry to one Fe(1) and one Fe(2) atom. is represented by the CIF card [CIF]
data_FeO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.754
_cell_length_b   5.754
_cell_length_c   5.754
_cell_angle_alpha   117.352
_cell_angle_beta   115.025
_cell_angle_gamma   96.750
_symmetry_Int_Tables_number   1
_cell_volume   141.310
_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  0.640  0.890  0.750  1.0
  Fe  Fe1  1  0.000  0.500  0.500  1.0
  Fe  Fe2  1  0.500  0.500  0.000  1.0
  Fe  Fe3  1  0.360  0.110  0.250  1.0
  O  O4  1  0.262  0.749  0.514  1.0
  O  O5  1  0.735  0.749  0.986  1.0
  O  O6  1  0.754  0.724  0.471  1.0
  O  O7  1  0.754  0.283  0.029  1.0
  O  O8  1  0.246  0.717  0.971  1.0
  O  O9  1  0.246  0.276  0.529  1.0
  O  O10  1  0.265  0.251  0.014  1.0
  O  O11  1  0.738  0.251  0.486  1.0
[/CIF]
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