The crystal structure described by Ca(FeO2)4 crystallizes in the monoclinic Cm space group. Ca(1) is bonded in a 4-coordinate geometry to two equivalent O(6) and two equivalent O(7) atoms. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(7), two equivalent O(4), and two equivalent O(5) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 51-55°. In the second Fe site, Fe(2) is bonded to one O(4), one O(8), two equivalent O(3), and two equivalent O(6) atoms to form a mixture of distorted corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 51-60°. In the third Fe site, Fe(3) is bonded to one O(1), one O(6), two equivalent O(2), and two equivalent O(8) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 53-55°. In the fourth Fe site, Fe(4) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(7) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 53-60°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(3) and two equivalent Fe(4) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Fe(1) and two equivalent Fe(3) atoms. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(4) and two equivalent Fe(2) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(2) and two equivalent Fe(1) atoms. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Fe(4) and two equivalent Fe(1) atoms. In the sixth O site, O(6) is bonded to two equivalent Ca(1), one Fe(3), and two equivalent Fe(2) atoms to form a mixture of distorted corner and edge-sharing OCa2Fe3 trigonal bipyramids. In the seventh O site, O(7) is bonded to two equivalent Ca(1), one Fe(1), and two equivalent Fe(4) atoms to form a mixture of corner and edge-sharing OCa2Fe3 trigonal bipyramids. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Fe(2) and two equivalent Fe(3) atoms. is represented by the CIF file [CIF]
data_Ca(FeO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.096
_cell_length_b   7.096
_cell_length_c   9.406
_cell_angle_alpha   49.304
_cell_angle_beta   49.304
_cell_angle_gamma   25.192
_symmetry_Int_Tables_number   1
_cell_volume   149.988
_cell_formula_units_Z   1
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  0.592  0.592  0.888  1.0
  Fe  Fe1  1  0.366  0.366  0.442  1.0
  Fe  Fe2  1  0.864  0.864  0.783  1.0
  Fe  Fe3  1  0.168  0.168  0.154  1.0
  Fe  Fe4  1  0.659  0.659  0.490  1.0
  O  O5  1  0.147  0.147  0.375  1.0
  O  O6  1  0.550  0.550  0.230  1.0
  O  O7  1  0.473  0.473  0.724  1.0
  O  O8  1  0.862  0.862  0.579  1.0
  O  O9  1  0.851  0.851  0.316  1.0
  O  O10  1  0.211  0.211  0.906  1.0
  O  O11  1  0.169  0.169  0.638  1.0
  O  O12  1  0.794  0.794  0.044  1.0
[/CIF]
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The crystal structure described by Ca(FeO2)4 crystallizes in the monoclinic Cm space group. Ca(1) is bonded in a 4-coordinate geometry to two equivalent O(6) and two equivalent O(7) atoms. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(7), two equivalent O(4), and two equivalent O(5) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 51-55°. In the second Fe site, Fe(2) is bonded to one O(4), one O(8), two equivalent O(3), and two equivalent O(6) atoms to form a mixture of distorted corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 51-60°. In the third Fe site, Fe(3) is bonded to one O(1), one O(6), two equivalent O(2), and two equivalent O(8) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 53-55°. In the fourth Fe site, Fe(4) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(7) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 53-60°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(3) and two equivalent Fe(4) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Fe(1) and two equivalent Fe(3) atoms. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(4) and two equivalent Fe(2) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(2) and two equivalent Fe(1) atoms. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Fe(4) and two equivalent Fe(1) atoms. In the sixth O site, O(6) is bonded to two equivalent Ca(1), one Fe(3), and two equivalent Fe(2) atoms to form a mixture of distorted corner and edge-sharing OCa2Fe3 trigonal bipyramids. In the seventh O site, O(7) is bonded to two equivalent Ca(1), one Fe(1), and two equivalent Fe(4) atoms to form a mixture of corner and edge-sharing OCa2Fe3 trigonal bipyramids. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Fe(2) and two equivalent Fe(3) atoms. is represented by the CIF file [CIF]
data_Ca(FeO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.096
_cell_length_b   7.096
_cell_length_c   9.406
_cell_angle_alpha   49.304
_cell_angle_beta   49.304
_cell_angle_gamma   25.192
_symmetry_Int_Tables_number   1
_cell_volume   149.988
_cell_formula_units_Z   1
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  0.592  0.592  0.888  1.0
  Fe  Fe1  1  0.366  0.366  0.442  1.0
  Fe  Fe2  1  0.864  0.864  0.783  1.0
  Fe  Fe3  1  0.168  0.168  0.154  1.0
  Fe  Fe4  1  0.659  0.659  0.490  1.0
  O  O5  1  0.147  0.147  0.375  1.0
  O  O6  1  0.550  0.550  0.230  1.0
  O  O7  1  0.473  0.473  0.724  1.0
  O  O8  1  0.862  0.862  0.579  1.0
  O  O9  1  0.851  0.851  0.316  1.0
  O  O10  1  0.211  0.211  0.906  1.0
  O  O11  1  0.169  0.169  0.638  1.0
  O  O12  1  0.794  0.794  0.044  1.0
[/CIF]
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