The structure described by Fe2O3 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), two equivalent O(1), and three equivalent O(3) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra are not tilted. In the second Fe site, Fe(2) is bonded in a 6-coordinate geometry to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Fe(2) and four equivalent Fe(1) atoms to form OFe6 octahedra that share corners with four equivalent O(3)Fe5 square pyramids, edges with two equivalent O(1)Fe6 octahedra, and edges with six equivalent O(3)Fe5 square pyramids. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one Fe(1) and two equivalent Fe(2) atoms. In the third O site, O(3) is bonded to two equivalent Fe(2) and three equivalent Fe(1) atoms to form OFe5 square pyramids that share corners with two equivalent O(1)Fe6 octahedra, edges with three equivalent O(1)Fe6 octahedra, and edges with four equivalent O(3)Fe5 square pyramids. The corner-sharing octahedral tilt angles are 9°. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to two equivalent Fe(2) atoms. is represented by the CIF card [CIF]
data_Fe2O3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.180
_cell_length_b   5.180
_cell_length_c   15.917
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   146.108
_symmetry_Int_Tables_number   1
_cell_volume   238.121
_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  0.635  0.365  0.047  1.0
  Fe  Fe1  1  0.365  0.635  0.953  1.0
  Fe  Fe2  1  0.635  0.365  0.453  1.0
  Fe  Fe3  1  0.365  0.635  0.547  1.0
  Fe  Fe4  1  0.096  0.904  0.647  1.0
  Fe  Fe5  1  0.904  0.096  0.353  1.0
  Fe  Fe6  1  0.904  0.096  0.147  1.0
  Fe  Fe7  1  0.096  0.904  0.853  1.0
  O  O8  1  0.000  0.000  0.500  1.0
  O  O9  1  0.000  0.000  0.000  1.0
  O  O10  1  0.471  0.529  0.853  1.0
  O  O11  1  0.529  0.471  0.147  1.0
  O  O12  1  0.529  0.471  0.353  1.0
  O  O13  1  0.471  0.529  0.647  1.0
  O  O14  1  0.728  0.272  0.927  1.0
  O  O15  1  0.272  0.728  0.073  1.0
  O  O16  1  0.272  0.728  0.427  1.0
  O  O17  1  0.728  0.272  0.573  1.0
  O  O18  1  0.179  0.821  0.750  1.0
  O  O19  1  0.821  0.179  0.250  1.0
[/CIF]
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The structure described by Fe2O3 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), two equivalent O(1), and three equivalent O(3) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra are not tilted. In the second Fe site, Fe(2) is bonded in a 6-coordinate geometry to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Fe(2) and four equivalent Fe(1) atoms to form OFe6 octahedra that share corners with four equivalent O(3)Fe5 square pyramids, edges with two equivalent O(1)Fe6 octahedra, and edges with six equivalent O(3)Fe5 square pyramids. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one Fe(1) and two equivalent Fe(2) atoms. In the third O site, O(3) is bonded to two equivalent Fe(2) and three equivalent Fe(1) atoms to form OFe5 square pyramids that share corners with two equivalent O(1)Fe6 octahedra, edges with three equivalent O(1)Fe6 octahedra, and edges with four equivalent O(3)Fe5 square pyramids. The corner-sharing octahedral tilt angles are 9°. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to two equivalent Fe(2) atoms. is represented by the CIF card [CIF]
data_Fe2O3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.180
_cell_length_b   5.180
_cell_length_c   15.917
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   146.108
_symmetry_Int_Tables_number   1
_cell_volume   238.121
_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  0.635  0.365  0.047  1.0
  Fe  Fe1  1  0.365  0.635  0.953  1.0
  Fe  Fe2  1  0.635  0.365  0.453  1.0
  Fe  Fe3  1  0.365  0.635  0.547  1.0
  Fe  Fe4  1  0.096  0.904  0.647  1.0
  Fe  Fe5  1  0.904  0.096  0.353  1.0
  Fe  Fe6  1  0.904  0.096  0.147  1.0
  Fe  Fe7  1  0.096  0.904  0.853  1.0
  O  O8  1  0.000  0.000  0.500  1.0
  O  O9  1  0.000  0.000  0.000  1.0
  O  O10  1  0.471  0.529  0.853  1.0
  O  O11  1  0.529  0.471  0.147  1.0
  O  O12  1  0.529  0.471  0.353  1.0
  O  O13  1  0.471  0.529  0.647  1.0
  O  O14  1  0.728  0.272  0.927  1.0
  O  O15  1  0.272  0.728  0.073  1.0
  O  O16  1  0.272  0.728  0.427  1.0
  O  O17  1  0.728  0.272  0.573  1.0
  O  O18  1  0.179  0.821  0.750  1.0
  O  O19  1  0.821  0.179  0.250  1.0
[/CIF]
.