The compound described by CaFe8(OF)8 crystallizes in the triclinic P1 space group. Ca(1) is bonded to one O(3), one O(6), one O(8), one F(1), one F(2), and one F(8) atom to form distorted CaO3F3 octahedra that share  a cornercorner with one Fe(5)O3F2 square pyramid, corners with two equivalent Fe(2)O3F2 trigonal bipyramids, corners with two equivalent Fe(1)O2F2 trigonal pyramids, edges with two equivalent Fe(7)O3F3 octahedra,  an edgeedge with one Fe(5)O3F2 square pyramid, and  an edgeedge with one Fe(1)O2F2 trigonal pyramid. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), one O(6), one F(1), and one F(2) atom to form FeO2F2 trigonal pyramids that share  a cornercorner with one Fe(7)O3F3 octahedra, corners with two equivalent Ca(1)O3F3 octahedra, corners with two equivalent Fe(5)O3F2 square pyramids,  a cornercorner with one Fe(2)O3F2 trigonal bipyramid,  an edgeedge with one Ca(1)O3F3 octahedra, and  an edgeedge with one Fe(7)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 22-78°. In the second Fe site, Fe(2) is bonded to one O(1), one O(4), one O(8), one F(1), and one F(6) atom to form distorted FeO3F2 trigonal bipyramids that share corners with two equivalent Ca(1)O3F3 octahedra, corners with two equivalent Fe(5)O3F2 square pyramids, corners with two equivalent Fe(8)O3F2 trigonal bipyramids,  a cornercorner with one Fe(1)O2F2 trigonal pyramid, and  an edgeedge with one Fe(3)O3F2 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 42-56°. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), one O(7), one F(6), and one F(7) atom to form a mixture of distorted corner and edge-sharing FeO3F2 trigonal bipyramids. In the fourth Fe site, Fe(4) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(5), one F(7), and one F(8) atom. In the fifth Fe site, Fe(5) is bonded to one O(4), one O(6), one O(8), one F(2), and one F(4) atom to form distorted FeO3F2 square pyramids that share  a cornercorner with one Ca(1)O3F3 octahedra, corners with two equivalent Fe(2)O3F2 trigonal bipyramids, corners with two equivalent Fe(1)O2F2 trigonal pyramids,  an edgeedge with one Ca(1)O3F3 octahedra,  an edgeedge with one Fe(7)O3F3 octahedra, and  an edgeedge with one Fe(8)O3F2 trigonal bipyramid. The corner-sharing octahedral tilt angles are 66°. In the sixth Fe site, Fe(6) is bonded to one O(2), one O(5), one O(7), one F(3), and one F(5) atom to form FeO3F2 trigonal bipyramids that share corners with two equivalent Fe(3)O3F2 trigonal bipyramids,  an edgeedge with one Fe(7)O3F3 octahedra, and  an edgeedge with one Fe(8)O3F2 trigonal bipyramid. In the seventh Fe site, Fe(7) is bonded to one O(3), one O(5), one O(6), one F(2), one F(5), and one F(8) atom to form distorted FeO3F3 octahedra that share  a cornercorner with one Fe(1)O2F2 trigonal pyramid, edges with two equivalent Ca(1)O3F3 octahedra,  an edgeedge with one Fe(5)O3F2 square pyramid,  an edgeedge with one Fe(6)O3F2 trigonal bipyramid, and  an edgeedge with one Fe(1)O2F2 trigonal pyramid. In the eighth Fe site, Fe(8) is bonded to one O(1), one O(4), one O(7), one F(3), and one F(4) atom to form a mixture of distorted corner and edge-sharing FeO3F2 trigonal bipyramids. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(8) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(3), one Fe(4), and one Fe(6) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Ca(1), one Fe(1), one Fe(4), and one Fe(7) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(5), and one Fe(8) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Fe(4), one Fe(6), and one Fe(7) atom. In the sixth O site, O(6) is bonded in a tetrahedral geometry to one Ca(1), one Fe(1), one Fe(5), and one Fe(7) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(6), and one Fe(8) atom. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to one Ca(1), one Fe(2), and one Fe(5) atom. There are eight inequivalent F sites. In the first F site, F(1) is bonded in a 3-coordinate geometry to one Ca(1), one Fe(1), and one Fe(2) atom. In the second F site, F(2) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Fe(1), one Fe(5), and one Fe(7) atom. In the third F site, F(3) is bonded in an L-shaped geometry to one Fe(6) and one Fe(8) atom. In the fourth F site, F(4) is bonded in an L-shaped geometry to one Fe(5) and one Fe(8) atom. In the fifth F site, F(5) is bonded in a distorted L-shaped geometry to one Fe(6) and one Fe(7) atom. In the sixth F site, F(6) is bonded in a water-like geometry to one Fe(2) and one Fe(3) atom. In the seventh F site, F(7) is bonded in a water-like geometry to one Fe(3) and one Fe(4) atom. In the eighth F site, F(8) is bonded in a 3-coordinate geometry to one Ca(1), one Fe(4), and one Fe(7) atom. is represented by the CIF file [CIF]
data_CaFe8(OF)8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.112
_cell_length_b   5.356
_cell_length_c   11.923
_cell_angle_alpha   88.078
_cell_angle_beta   92.098
_cell_angle_gamma   91.670
_symmetry_Int_Tables_number   1
_cell_volume   325.961
_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  0.553  0.023  0.987  1.0
  Fe  Fe1  1  0.046  0.653  0.985  1.0
  Fe  Fe2  1  0.045  0.076  0.249  1.0
  Fe  Fe3  1  0.943  0.929  0.497  1.0
  Fe  Fe4  1  0.084  0.044  0.744  1.0
  Fe  Fe5  1  0.555  0.449  0.147  1.0
  Fe  Fe6  1  0.439  0.572  0.621  1.0
  Fe  Fe7  1  0.493  0.521  0.859  1.0
  Fe  Fe8  1  0.412  0.586  0.374  1.0
  O  O9  1  0.163  0.845  0.369  1.0
  O  O10  1  0.188  0.834  0.620  1.0
  O  O11  1  0.238  0.837  0.869  1.0
  O  O12  1  0.297  0.355  0.256  1.0
  O  O13  1  0.318  0.333  0.738  1.0
  O  O14  1  0.674  0.624  0.007  1.0
  O  O15  1  0.656  0.687  0.495  1.0
  O  O16  1  0.777  0.180  0.141  1.0
  F  F17  1  0.215  0.855  0.125  1.0
  F  F18  1  0.271  0.337  0.020  1.0
  F  F19  1  0.271  0.367  0.497  1.0
  F  F20  1  0.682  0.691  0.257  1.0
  F  F21  1  0.705  0.702  0.734  1.0
  F  F22  1  0.818  0.174  0.377  1.0
  F  F23  1  0.831  0.156  0.617  1.0
  F  F24  1  0.824  0.186  0.855  1.0
[/CIF]
.
The compound described by CaFe8(OF)8 crystallizes in the triclinic P1 space group. Ca(1) is bonded to one O(3), one O(6), one O(8), one F(1), one F(2), and one F(8) atom to form distorted CaO3F3 octahedra that share  a cornercorner with one Fe(5)O3F2 square pyramid, corners with two equivalent Fe(2)O3F2 trigonal bipyramids, corners with two equivalent Fe(1)O2F2 trigonal pyramids, edges with two equivalent Fe(7)O3F3 octahedra,  an edgeedge with one Fe(5)O3F2 square pyramid, and  an edgeedge with one Fe(1)O2F2 trigonal pyramid. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), one O(6), one F(1), and one F(2) atom to form FeO2F2 trigonal pyramids that share  a cornercorner with one Fe(7)O3F3 octahedra, corners with two equivalent Ca(1)O3F3 octahedra, corners with two equivalent Fe(5)O3F2 square pyramids,  a cornercorner with one Fe(2)O3F2 trigonal bipyramid,  an edgeedge with one Ca(1)O3F3 octahedra, and  an edgeedge with one Fe(7)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 22-78°. In the second Fe site, Fe(2) is bonded to one O(1), one O(4), one O(8), one F(1), and one F(6) atom to form distorted FeO3F2 trigonal bipyramids that share corners with two equivalent Ca(1)O3F3 octahedra, corners with two equivalent Fe(5)O3F2 square pyramids, corners with two equivalent Fe(8)O3F2 trigonal bipyramids,  a cornercorner with one Fe(1)O2F2 trigonal pyramid, and  an edgeedge with one Fe(3)O3F2 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 42-56°. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), one O(7), one F(6), and one F(7) atom to form a mixture of distorted corner and edge-sharing FeO3F2 trigonal bipyramids. In the fourth Fe site, Fe(4) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(5), one F(7), and one F(8) atom. In the fifth Fe site, Fe(5) is bonded to one O(4), one O(6), one O(8), one F(2), and one F(4) atom to form distorted FeO3F2 square pyramids that share  a cornercorner with one Ca(1)O3F3 octahedra, corners with two equivalent Fe(2)O3F2 trigonal bipyramids, corners with two equivalent Fe(1)O2F2 trigonal pyramids,  an edgeedge with one Ca(1)O3F3 octahedra,  an edgeedge with one Fe(7)O3F3 octahedra, and  an edgeedge with one Fe(8)O3F2 trigonal bipyramid. The corner-sharing octahedral tilt angles are 66°. In the sixth Fe site, Fe(6) is bonded to one O(2), one O(5), one O(7), one F(3), and one F(5) atom to form FeO3F2 trigonal bipyramids that share corners with two equivalent Fe(3)O3F2 trigonal bipyramids,  an edgeedge with one Fe(7)O3F3 octahedra, and  an edgeedge with one Fe(8)O3F2 trigonal bipyramid. In the seventh Fe site, Fe(7) is bonded to one O(3), one O(5), one O(6), one F(2), one F(5), and one F(8) atom to form distorted FeO3F3 octahedra that share  a cornercorner with one Fe(1)O2F2 trigonal pyramid, edges with two equivalent Ca(1)O3F3 octahedra,  an edgeedge with one Fe(5)O3F2 square pyramid,  an edgeedge with one Fe(6)O3F2 trigonal bipyramid, and  an edgeedge with one Fe(1)O2F2 trigonal pyramid. In the eighth Fe site, Fe(8) is bonded to one O(1), one O(4), one O(7), one F(3), and one F(4) atom to form a mixture of distorted corner and edge-sharing FeO3F2 trigonal bipyramids. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(8) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(3), one Fe(4), and one Fe(6) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Ca(1), one Fe(1), one Fe(4), and one Fe(7) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(5), and one Fe(8) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Fe(4), one Fe(6), and one Fe(7) atom. In the sixth O site, O(6) is bonded in a tetrahedral geometry to one Ca(1), one Fe(1), one Fe(5), and one Fe(7) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(6), and one Fe(8) atom. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to one Ca(1), one Fe(2), and one Fe(5) atom. There are eight inequivalent F sites. In the first F site, F(1) is bonded in a 3-coordinate geometry to one Ca(1), one Fe(1), and one Fe(2) atom. In the second F site, F(2) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Fe(1), one Fe(5), and one Fe(7) atom. In the third F site, F(3) is bonded in an L-shaped geometry to one Fe(6) and one Fe(8) atom. In the fourth F site, F(4) is bonded in an L-shaped geometry to one Fe(5) and one Fe(8) atom. In the fifth F site, F(5) is bonded in a distorted L-shaped geometry to one Fe(6) and one Fe(7) atom. In the sixth F site, F(6) is bonded in a water-like geometry to one Fe(2) and one Fe(3) atom. In the seventh F site, F(7) is bonded in a water-like geometry to one Fe(3) and one Fe(4) atom. In the eighth F site, F(8) is bonded in a 3-coordinate geometry to one Ca(1), one Fe(4), and one Fe(7) atom. is represented by the CIF file [CIF]
data_CaFe8(OF)8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.112
_cell_length_b   5.356
_cell_length_c   11.923
_cell_angle_alpha   88.078
_cell_angle_beta   92.098
_cell_angle_gamma   91.670
_symmetry_Int_Tables_number   1
_cell_volume   325.961
_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  0.553  0.023  0.987  1.0
  Fe  Fe1  1  0.046  0.653  0.985  1.0
  Fe  Fe2  1  0.045  0.076  0.249  1.0
  Fe  Fe3  1  0.943  0.929  0.497  1.0
  Fe  Fe4  1  0.084  0.044  0.744  1.0
  Fe  Fe5  1  0.555  0.449  0.147  1.0
  Fe  Fe6  1  0.439  0.572  0.621  1.0
  Fe  Fe7  1  0.493  0.521  0.859  1.0
  Fe  Fe8  1  0.412  0.586  0.374  1.0
  O  O9  1  0.163  0.845  0.369  1.0
  O  O10  1  0.188  0.834  0.620  1.0
  O  O11  1  0.238  0.837  0.869  1.0
  O  O12  1  0.297  0.355  0.256  1.0
  O  O13  1  0.318  0.333  0.738  1.0
  O  O14  1  0.674  0.624  0.007  1.0
  O  O15  1  0.656  0.687  0.495  1.0
  O  O16  1  0.777  0.180  0.141  1.0
  F  F17  1  0.215  0.855  0.125  1.0
  F  F18  1  0.271  0.337  0.020  1.0
  F  F19  1  0.271  0.367  0.497  1.0
  F  F20  1  0.682  0.691  0.257  1.0
  F  F21  1  0.705  0.702  0.734  1.0
  F  F22  1  0.818  0.174  0.377  1.0
  F  F23  1  0.831  0.156  0.617  1.0
  F  F24  1  0.824  0.186  0.855  1.0
[/CIF]
.