The structure described by Sr8Fe8O23 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to one O(1), one O(5), two equivalent O(3), four equivalent O(2), and four equivalent O(4) atoms to form SrO12 cuboctahedra that share corners with six equivalent Sr(1)O12 cuboctahedra, faces with two equivalent Sr(1)O12 cuboctahedra, faces with two equivalent Fe(1)O6 octahedra, faces with four equivalent Fe(2)O6 octahedra, and faces with two equivalent Fe(3)O5 square pyramids. In the second Sr site, Sr(2) is bonded in a distorted q6 geometry to one O(1), two equivalent O(3), four equivalent O(2), and four equivalent O(4) atoms. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with four equivalent Fe(2)O6 octahedra, and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. In the second Fe site, Fe(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Fe(3)O5 square pyramids, and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the third Fe site, Fe(3) is bonded to one O(5) and four equivalent O(4) atoms to form FeO5 square pyramids that share corners with four equivalent Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O5 square pyramid, and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 12°. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Fe(1) atoms to form a mixture of distorted corner and face-sharing OSr4Fe2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to two equivalent Sr(1), two equivalent Sr(2), one Fe(1), and one Fe(2) atom to form a mixture of distorted corner, edge, and face-sharing OSr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 0-61°. In the third O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Fe(2) atoms. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), one Fe(2), and one Fe(3) atom. In the fifth O site, O(5) is bonded to four equivalent Sr(1) and two equivalent Fe(3) atoms to form distorted corner-sharing OSr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. is represented by the CIF card [CIF]
data_Sr8Fe8O23
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.606
_cell_length_b   8.606
_cell_length_c   8.607
_cell_angle_alpha   101.429
_cell_angle_beta   101.429
_cell_angle_gamma   127.135
_symmetry_Int_Tables_number   1
_cell_volume   455.133
_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
  Sr  Sr0  1  0.750  0.500  0.250  1.0
  Sr  Sr1  1  0.500  0.250  0.750  1.0
  Sr  Sr2  1  0.500  0.750  0.250  1.0
  Sr  Sr3  1  0.250  0.500  0.750  1.0
  Sr  Sr4  1  0.259  0.000  0.259  1.0
  Sr  Sr5  1  1.000  0.741  0.741  1.0
  Sr  Sr6  1  0.000  0.259  0.259  1.0
  Sr  Sr7  1  0.741  1.000  0.741  1.0
  Fe  Fe8  1  0.750  0.250  0.500  1.0
  Fe  Fe9  1  0.250  0.750  0.500  1.0
  Fe  Fe10  1  0.000  0.500  0.000  1.0
  Fe  Fe11  1  0.500  0.500  0.500  1.0
  Fe  Fe12  1  0.000  0.000  0.500  1.0
  Fe  Fe13  1  0.500  0.000  0.000  1.0
  Fe  Fe14  1  0.252  0.252  1.000  1.0
  Fe  Fe15  1  0.748  0.748  0.000  1.0
  O  O16  1  0.000  0.500  0.500  1.0
  O  O17  1  0.500  0.000  0.500  1.0
  O  O18  1  0.126  0.874  0.500  1.0
  O  O19  1  0.874  0.374  0.748  1.0
  O  O20  1  0.626  0.126  0.252  1.0
  O  O21  1  0.374  0.626  0.500  1.0
  O  O22  1  0.874  0.126  0.500  1.0
  O  O23  1  0.126  0.626  0.252  1.0
  O  O24  1  0.374  0.874  0.748  1.0
  O  O25  1  0.626  0.374  0.500  1.0
  O  O26  1  0.739  0.261  0.000  1.0
  O  O27  1  0.261  0.261  0.521  1.0
  O  O28  1  0.739  0.739  0.479  1.0
  O  O29  1  0.261  0.739  0.000  1.0
  O  O30  1  0.104  0.104  0.760  1.0
  O  O31  1  0.344  0.344  0.240  1.0
  O  O32  1  0.500  0.500  0.000  1.0
  O  O33  1  0.656  0.896  0.000  1.0
  O  O34  1  0.896  0.896  0.240  1.0
  O  O35  1  0.656  0.656  0.760  1.0
  O  O36  1  0.896  0.656  0.000  1.0
  O  O37  1  0.344  0.104  1.000  1.0
  O  O38  1  0.104  0.344  1.000  1.0
[/CIF]
.
The structure described by Sr8Fe8O23 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to one O(1), one O(5), two equivalent O(3), four equivalent O(2), and four equivalent O(4) atoms to form SrO12 cuboctahedra that share corners with six equivalent Sr(1)O12 cuboctahedra, faces with two equivalent Sr(1)O12 cuboctahedra, faces with two equivalent Fe(1)O6 octahedra, faces with four equivalent Fe(2)O6 octahedra, and faces with two equivalent Fe(3)O5 square pyramids. In the second Sr site, Sr(2) is bonded in a distorted q6 geometry to one O(1), two equivalent O(3), four equivalent O(2), and four equivalent O(4) atoms. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with four equivalent Fe(2)O6 octahedra, and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. In the second Fe site, Fe(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Fe(3)O5 square pyramids, and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the third Fe site, Fe(3) is bonded to one O(5) and four equivalent O(4) atoms to form FeO5 square pyramids that share corners with four equivalent Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O5 square pyramid, and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 12°. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Fe(1) atoms to form a mixture of distorted corner and face-sharing OSr4Fe2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to two equivalent Sr(1), two equivalent Sr(2), one Fe(1), and one Fe(2) atom to form a mixture of distorted corner, edge, and face-sharing OSr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 0-61°. In the third O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Fe(2) atoms. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), one Fe(2), and one Fe(3) atom. In the fifth O site, O(5) is bonded to four equivalent Sr(1) and two equivalent Fe(3) atoms to form distorted corner-sharing OSr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. is represented by the CIF card [CIF]
data_Sr8Fe8O23
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.606
_cell_length_b   8.606
_cell_length_c   8.607
_cell_angle_alpha   101.429
_cell_angle_beta   101.429
_cell_angle_gamma   127.135
_symmetry_Int_Tables_number   1
_cell_volume   455.133
_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
  Sr  Sr0  1  0.750  0.500  0.250  1.0
  Sr  Sr1  1  0.500  0.250  0.750  1.0
  Sr  Sr2  1  0.500  0.750  0.250  1.0
  Sr  Sr3  1  0.250  0.500  0.750  1.0
  Sr  Sr4  1  0.259  0.000  0.259  1.0
  Sr  Sr5  1  1.000  0.741  0.741  1.0
  Sr  Sr6  1  0.000  0.259  0.259  1.0
  Sr  Sr7  1  0.741  1.000  0.741  1.0
  Fe  Fe8  1  0.750  0.250  0.500  1.0
  Fe  Fe9  1  0.250  0.750  0.500  1.0
  Fe  Fe10  1  0.000  0.500  0.000  1.0
  Fe  Fe11  1  0.500  0.500  0.500  1.0
  Fe  Fe12  1  0.000  0.000  0.500  1.0
  Fe  Fe13  1  0.500  0.000  0.000  1.0
  Fe  Fe14  1  0.252  0.252  1.000  1.0
  Fe  Fe15  1  0.748  0.748  0.000  1.0
  O  O16  1  0.000  0.500  0.500  1.0
  O  O17  1  0.500  0.000  0.500  1.0
  O  O18  1  0.126  0.874  0.500  1.0
  O  O19  1  0.874  0.374  0.748  1.0
  O  O20  1  0.626  0.126  0.252  1.0
  O  O21  1  0.374  0.626  0.500  1.0
  O  O22  1  0.874  0.126  0.500  1.0
  O  O23  1  0.126  0.626  0.252  1.0
  O  O24  1  0.374  0.874  0.748  1.0
  O  O25  1  0.626  0.374  0.500  1.0
  O  O26  1  0.739  0.261  0.000  1.0
  O  O27  1  0.261  0.261  0.521  1.0
  O  O28  1  0.739  0.739  0.479  1.0
  O  O29  1  0.261  0.739  0.000  1.0
  O  O30  1  0.104  0.104  0.760  1.0
  O  O31  1  0.344  0.344  0.240  1.0
  O  O32  1  0.500  0.500  0.000  1.0
  O  O33  1  0.656  0.896  0.000  1.0
  O  O34  1  0.896  0.896  0.240  1.0
  O  O35  1  0.656  0.656  0.760  1.0
  O  O36  1  0.896  0.656  0.000  1.0
  O  O37  1  0.344  0.104  1.000  1.0
  O  O38  1  0.104  0.344  1.000  1.0
[/CIF]
.