The compound described by Ca2Fe2O5 crystallizes in the triclinic P-1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms to form distorted CaO6 pentagonal pyramids that share  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra,  an edgeedge with one Fe(2)O6 octahedra,  an edgeedge with one Fe(3)O6 octahedra, and  an edgeedge with one Ca(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 20-76°. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and two equivalent O(3) atoms. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(5), and two equivalent O(4) atoms. In the second Fe site, Fe(2) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with two equivalent Fe(3)O6 octahedra, corners with two equivalent Ca(1)O6 pentagonal pyramids, and edges with two equivalent Ca(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 29°. In the third Fe site, Fe(3) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms to form distorted FeO6 octahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with four equivalent Ca(1)O6 pentagonal pyramids, and edges with two equivalent Ca(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 29°. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Ca(2), two equivalent Ca(1), one Fe(1), and one Fe(3) atom to form a mixture of distorted edge and corner-sharing OCa3Fe2 trigonal bipyramids. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Fe(1), and one Fe(3) atom. In the third O site, O(3) is bonded to one Ca(1), two equivalent Ca(2), one Fe(1), and one Fe(2) atom to form a mixture of distorted edge and corner-sharing OCa3Fe2 trigonal bipyramids. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(2), one Fe(2), and two equivalent Fe(1) atoms. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(2), one Fe(1), one Fe(2), and one Fe(3) atom. is represented by the CIF file [CIF]
data_Ca2Fe2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.031
_cell_length_b   6.507
_cell_length_c   6.531
_cell_angle_alpha   109.213
_cell_angle_beta   96.868
_cell_angle_gamma   103.216
_symmetry_Int_Tables_number   1
_cell_volume   230.262
_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  0.716  0.891  0.982  1.0
  Ca  Ca1  1  0.242  0.488  0.618  1.0
  Ca  Ca2  1  0.758  0.512  0.382  1.0
  Ca  Ca3  1  0.284  0.109  0.018  1.0
  Fe  Fe4  1  0.662  0.202  0.655  1.0
  Fe  Fe5  1  0.000  0.000  0.500  1.0
  Fe  Fe6  1  0.338  0.798  0.345  1.0
  Fe  Fe7  1  0.000  0.500  0.000  1.0
  O  O8  1  0.343  0.752  0.022  1.0
  O  O9  1  0.782  0.532  0.751  1.0
  O  O10  1  0.845  0.188  0.393  1.0
  O  O11  1  0.641  0.855  0.550  1.0
  O  O12  1  0.058  0.234  0.798  1.0
  O  O13  1  0.942  0.766  0.202  1.0
  O  O14  1  0.359  0.145  0.450  1.0
  O  O15  1  0.155  0.812  0.607  1.0
  O  O16  1  0.218  0.468  0.249  1.0
  O  O17  1  0.657  0.248  0.978  1.0
[/CIF]
.
The compound described by Ca2Fe2O5 crystallizes in the triclinic P-1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms to form distorted CaO6 pentagonal pyramids that share  a cornercorner with one Fe(2)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra,  an edgeedge with one Fe(2)O6 octahedra,  an edgeedge with one Fe(3)O6 octahedra, and  an edgeedge with one Ca(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 20-76°. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and two equivalent O(3) atoms. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(5), and two equivalent O(4) atoms. In the second Fe site, Fe(2) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with two equivalent Fe(3)O6 octahedra, corners with two equivalent Ca(1)O6 pentagonal pyramids, and edges with two equivalent Ca(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 29°. In the third Fe site, Fe(3) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms to form distorted FeO6 octahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with four equivalent Ca(1)O6 pentagonal pyramids, and edges with two equivalent Ca(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 29°. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Ca(2), two equivalent Ca(1), one Fe(1), and one Fe(3) atom to form a mixture of distorted edge and corner-sharing OCa3Fe2 trigonal bipyramids. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Fe(1), and one Fe(3) atom. In the third O site, O(3) is bonded to one Ca(1), two equivalent Ca(2), one Fe(1), and one Fe(2) atom to form a mixture of distorted edge and corner-sharing OCa3Fe2 trigonal bipyramids. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(2), one Fe(2), and two equivalent Fe(1) atoms. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(2), one Fe(1), one Fe(2), and one Fe(3) atom. is represented by the CIF file [CIF]
data_Ca2Fe2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.031
_cell_length_b   6.507
_cell_length_c   6.531
_cell_angle_alpha   109.213
_cell_angle_beta   96.868
_cell_angle_gamma   103.216
_symmetry_Int_Tables_number   1
_cell_volume   230.262
_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  0.716  0.891  0.982  1.0
  Ca  Ca1  1  0.242  0.488  0.618  1.0
  Ca  Ca2  1  0.758  0.512  0.382  1.0
  Ca  Ca3  1  0.284  0.109  0.018  1.0
  Fe  Fe4  1  0.662  0.202  0.655  1.0
  Fe  Fe5  1  0.000  0.000  0.500  1.0
  Fe  Fe6  1  0.338  0.798  0.345  1.0
  Fe  Fe7  1  0.000  0.500  0.000  1.0
  O  O8  1  0.343  0.752  0.022  1.0
  O  O9  1  0.782  0.532  0.751  1.0
  O  O10  1  0.845  0.188  0.393  1.0
  O  O11  1  0.641  0.855  0.550  1.0
  O  O12  1  0.058  0.234  0.798  1.0
  O  O13  1  0.942  0.766  0.202  1.0
  O  O14  1  0.359  0.145  0.450  1.0
  O  O15  1  0.155  0.812  0.607  1.0
  O  O16  1  0.218  0.468  0.249  1.0
  O  O17  1  0.657  0.248  0.978  1.0
[/CIF]
.