The material described by CaFe2O4 crystallizes in the triclinic P-1 space group. Ca(1) is bonded in a 6-coordinate geometry to one Fe(1), one Fe(2), one O(1), one O(2), one O(3), and one O(4) atom. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 8-coordinate geometry to two equivalent Ca(1), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. In the second Fe site, Fe(2) is bonded in a 8-coordinate geometry to two equivalent Ca(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. In the third Fe site, Fe(3) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted edge-sharing FeO6 octahedra. In the fourth Fe site, Fe(4) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form distorted edge-sharing FeO6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ca(1), one Fe(1), one Fe(3), and one Fe(4) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(1), one Fe(1), one Fe(2), and one Fe(4) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), one Fe(1), one Fe(2), and one Fe(3) atom. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Fe(2), one Fe(3), and one Fe(4) atom. is represented by the CIF file [CIF]
data_Ca(FeO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.186
_cell_length_b   6.225
_cell_length_c   6.233
_cell_angle_alpha   118.853
_cell_angle_beta   117.654
_cell_angle_gamma   92.069
_symmetry_Int_Tables_number   1
_cell_volume   175.451
_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  0.137  0.880  0.741  1.0
  Ca  Ca1  1  0.863  0.120  0.259  1.0
  Fe  Fe2  1  0.000  0.500  0.500  1.0
  Fe  Fe3  1  0.500  0.000  0.000  1.0
  Fe  Fe4  1  0.500  0.500  0.500  1.0
  Fe  Fe5  1  0.500  0.500  0.000  1.0
  O  O6  1  0.720  0.687  0.542  1.0
  O  O7  1  0.753  0.286  0.946  1.0
  O  O8  1  0.705  0.264  0.546  1.0
  O  O9  1  0.714  0.764  0.985  1.0
  O  O10  1  0.295  0.736  0.454  1.0
  O  O11  1  0.247  0.714  0.054  1.0
  O  O12  1  0.286  0.236  0.015  1.0
  O  O13  1  0.280  0.313  0.458  1.0
[/CIF]
.
The material described by CaFe2O4 crystallizes in the triclinic P-1 space group. Ca(1) is bonded in a 6-coordinate geometry to one Fe(1), one Fe(2), one O(1), one O(2), one O(3), and one O(4) atom. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 8-coordinate geometry to two equivalent Ca(1), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. In the second Fe site, Fe(2) is bonded in a 8-coordinate geometry to two equivalent Ca(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. In the third Fe site, Fe(3) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted edge-sharing FeO6 octahedra. In the fourth Fe site, Fe(4) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form distorted edge-sharing FeO6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ca(1), one Fe(1), one Fe(3), and one Fe(4) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(1), one Fe(1), one Fe(2), and one Fe(4) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), one Fe(1), one Fe(2), and one Fe(3) atom. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Fe(2), one Fe(3), and one Fe(4) atom. is represented by the CIF file [CIF]
data_Ca(FeO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.186
_cell_length_b   6.225
_cell_length_c   6.233
_cell_angle_alpha   118.853
_cell_angle_beta   117.654
_cell_angle_gamma   92.069
_symmetry_Int_Tables_number   1
_cell_volume   175.451
_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  0.137  0.880  0.741  1.0
  Ca  Ca1  1  0.863  0.120  0.259  1.0
  Fe  Fe2  1  0.000  0.500  0.500  1.0
  Fe  Fe3  1  0.500  0.000  0.000  1.0
  Fe  Fe4  1  0.500  0.500  0.500  1.0
  Fe  Fe5  1  0.500  0.500  0.000  1.0
  O  O6  1  0.720  0.687  0.542  1.0
  O  O7  1  0.753  0.286  0.946  1.0
  O  O8  1  0.705  0.264  0.546  1.0
  O  O9  1  0.714  0.764  0.985  1.0
  O  O10  1  0.295  0.736  0.454  1.0
  O  O11  1  0.247  0.714  0.054  1.0
  O  O12  1  0.286  0.236  0.015  1.0
  O  O13  1  0.280  0.313  0.458  1.0
[/CIF]
.