The crystal structure described by CaFe2O4 is Spinel-like structured and crystallizes in the orthorhombic Imma space group. Ca(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CaO6 octahedra that share corners with six equivalent Fe(1)O4 tetrahedra, edges with two equivalent Ca(1)O6 octahedra, and edges with four equivalent Fe(2)O6 octahedra. 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 FeO4 tetrahedra that share corners with six equivalent Ca(1)O6 octahedra and corners with six equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-59°. 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, edges with two equivalent Fe(2)O6 octahedra, and edges with four equivalent Ca(1)O6 octahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to two equivalent Ca(1), one Fe(1), and one Fe(2) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Ca(1), one Fe(1), and two equivalent Fe(2) atoms. is represented by the CIF file [CIF]
data_Ca(FeO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.266
_cell_length_b   6.266
_cell_length_c   6.266
_cell_angle_alpha   120.016
_cell_angle_beta   119.996
_cell_angle_gamma   89.990
_symmetry_Int_Tables_number   1
_cell_volume   173.942
_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
  Ca  Ca0  1  0.000  0.000  0.500  1.0
  Ca  Ca1  1  0.000  0.500  0.000  1.0
  Fe  Fe2  1  0.611  0.861  0.750  1.0
  Fe  Fe3  1  0.389  0.139  0.250  1.0
  Fe  Fe4  1  0.500  0.500  0.000  1.0
  Fe  Fe5  1  0.000  0.500  0.500  1.0
  O  O6  1  0.281  0.272  0.009  1.0
  O  O7  1  0.260  0.275  0.515  1.0
  O  O8  1  0.762  0.272  0.491  1.0
  O  O9  1  0.260  0.744  0.985  1.0
  O  O10  1  0.740  0.256  0.015  1.0
  O  O11  1  0.740  0.725  0.485  1.0
  O  O12  1  0.238  0.728  0.509  1.0
  O  O13  1  0.719  0.728  0.991  1.0
[/CIF]
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The crystal structure described by CaFe2O4 is Spinel-like structured and crystallizes in the orthorhombic Imma space group. Ca(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CaO6 octahedra that share corners with six equivalent Fe(1)O4 tetrahedra, edges with two equivalent Ca(1)O6 octahedra, and edges with four equivalent Fe(2)O6 octahedra. 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 FeO4 tetrahedra that share corners with six equivalent Ca(1)O6 octahedra and corners with six equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-59°. 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, edges with two equivalent Fe(2)O6 octahedra, and edges with four equivalent Ca(1)O6 octahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to two equivalent Ca(1), one Fe(1), and one Fe(2) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Ca(1), one Fe(1), and two equivalent Fe(2) atoms. is represented by the CIF file [CIF]
data_Ca(FeO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.266
_cell_length_b   6.266
_cell_length_c   6.266
_cell_angle_alpha   120.016
_cell_angle_beta   119.996
_cell_angle_gamma   89.990
_symmetry_Int_Tables_number   1
_cell_volume   173.942
_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
  Ca  Ca0  1  0.000  0.000  0.500  1.0
  Ca  Ca1  1  0.000  0.500  0.000  1.0
  Fe  Fe2  1  0.611  0.861  0.750  1.0
  Fe  Fe3  1  0.389  0.139  0.250  1.0
  Fe  Fe4  1  0.500  0.500  0.000  1.0
  Fe  Fe5  1  0.000  0.500  0.500  1.0
  O  O6  1  0.281  0.272  0.009  1.0
  O  O7  1  0.260  0.275  0.515  1.0
  O  O8  1  0.762  0.272  0.491  1.0
  O  O9  1  0.260  0.744  0.985  1.0
  O  O10  1  0.740  0.256  0.015  1.0
  O  O11  1  0.740  0.725  0.485  1.0
  O  O12  1  0.238  0.728  0.509  1.0
  O  O13  1  0.719  0.728  0.991  1.0
[/CIF]
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