The material structure described by Sr4FeRh2O9 crystallizes in the trigonal P321 space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and four equivalent O(4) atoms. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one O(2), one O(4), two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms. In the third Sr site, Sr(3) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(5) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to three equivalent O(4) and three equivalent O(5) atoms to form distorted FeO6 pentagonal pyramids that share  a faceface with one Rh(1)O6 octahedra and  a faceface with one Rh(3)O6 octahedra. In the second Fe site, Fe(2) is bonded to six equivalent O(3) atoms to form distorted FeO6 pentagonal pyramids that share faces with two equivalent Rh(2)O6 octahedra. There are three inequivalent Rh sites. In the first Rh site, Rh(1) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form RhO6 octahedra that share  a faceface with one Rh(3)O6 octahedra and  a faceface with one Fe(1)O6 pentagonal pyramid. In the second Rh site, Rh(2) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form RhO6 octahedra that share  a faceface with one Rh(2)O6 octahedra and  a faceface with one Fe(2)O6 pentagonal pyramid. In the third Rh site, Rh(3) is bonded to three equivalent O(1) and three equivalent O(5) atoms to form RhO6 octahedra that share  a faceface with one Rh(1)O6 octahedra and  a faceface with one Fe(1)O6 pentagonal pyramid. There are five inequivalent O sites. In the first O site, O(4) is bonded in a 3-coordinate geometry to one Sr(2), two equivalent Sr(1), one Fe(1), and one Rh(1) atom. In the second O site, O(5) is bonded to two equivalent Sr(2), two equivalent Sr(3), one Fe(1), and one Rh(3) atom to form distorted OSr4FeRh octahedra that share corners with two equivalent O(2)Sr4Rh2 octahedra, corners with three equivalent O(5)Sr4FeRh octahedra, corners with three equivalent O(1)Sr4Rh2 octahedra,  an edgeedge with one O(1)Sr4Rh2 octahedra, faces with two equivalent O(1)Sr4Rh2 octahedra, and faces with three equivalent O(5)Sr4FeRh octahedra. The corner-sharing octahedral tilt angles range from 1-68°. In the third O site, O(1) is bonded to one Sr(1), one Sr(3), two equivalent Sr(2), one Rh(1), and one Rh(3) atom to form OSr4Rh2 octahedra that share corners with two equivalent O(1)Sr4Rh2 octahedra, corners with two equivalent O(2)Sr4Rh2 octahedra, corners with three equivalent O(5)Sr4FeRh octahedra,  an edgeedge with one O(5)Sr4FeRh octahedra,  an edgeedge with one O(2)Sr4Rh2 octahedra, faces with two equivalent O(5)Sr4FeRh octahedra, and faces with two equivalent O(1)Sr4Rh2 octahedra. The corner-sharing octahedral tilt angles range from 1-68°. In the fourth O site, O(2) is bonded to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Rh(2) atoms to form OSr4Rh2 octahedra that share corners with four equivalent O(5)Sr4FeRh octahedra, corners with four equivalent O(1)Sr4Rh2 octahedra, edges with two equivalent O(1)Sr4Rh2 octahedra, and faces with two equivalent O(2)Sr4Rh2 octahedra. The corner-sharing octahedral tilt angles range from 27-58°. In the fifth O site, O(3) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(3), two equivalent Sr(2), one Fe(2), and one Rh(2) atom. is represented by the CIF card [CIF]
data_Sr4FeRh2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.737
_cell_length_b   9.737
_cell_length_c   8.132
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   667.726
_cell_formula_units_Z   3
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  0.674  0.674  0.500  1.0
  Sr  Sr1  1  0.326  0.000  0.500  1.0
  Sr  Sr2  1  0.000  0.326  0.500  1.0
  Sr  Sr3  1  0.695  0.027  0.246  1.0
  Sr  Sr4  1  0.973  0.667  0.246  1.0
  Sr  Sr5  1  0.305  0.333  0.754  1.0
  Sr  Sr6  1  0.333  0.305  0.246  1.0
  Sr  Sr7  1  0.027  0.695  0.754  1.0
  Sr  Sr8  1  0.667  0.973  0.754  1.0
  Sr  Sr9  1  0.636  0.636  0.000  1.0
  Sr  Sr10  1  0.364  0.000  0.000  1.0
  Sr  Sr11  1  0.000  0.364  0.000  1.0
  Fe  Fe12  1  0.667  0.333  0.765  1.0
  Fe  Fe13  1  0.333  0.667  0.235  1.0
  Fe  Fe14  1  0.000  0.000  0.000  1.0
  Rh  Rh15  1  0.667  0.333  0.429  1.0
  Rh  Rh16  1  0.333  0.667  0.571  1.0
  Rh  Rh17  1  0.000  0.000  0.338  1.0
  Rh  Rh18  1  0.000  0.000  0.662  1.0
  Rh  Rh19  1  0.667  0.333  0.105  1.0
  Rh  Rh20  1  0.333  0.667  0.895  1.0
  O  O21  1  0.843  0.350  0.266  1.0
  O  O22  1  0.650  0.493  0.266  1.0
  O  O23  1  0.157  0.507  0.734  1.0
  O  O24  1  0.507  0.157  0.266  1.0
  O  O25  1  0.350  0.843  0.734  1.0
  O  O26  1  0.493  0.650  0.734  1.0
  O  O27  1  0.164  0.164  0.500  1.0
  O  O28  1  0.836  0.000  0.500  1.0
  O  O29  1  0.000  0.836  0.500  1.0
  O  O30  1  0.007  0.162  0.176  1.0
  O  O31  1  0.838  0.845  0.176  1.0
  O  O32  1  0.993  0.155  0.824  1.0
  O  O33  1  0.155  0.993  0.176  1.0
  O  O34  1  0.162  0.007  0.824  1.0
  O  O35  1  0.845  0.838  0.824  1.0
  O  O36  1  0.318  0.504  0.409  1.0
  O  O37  1  0.496  0.814  0.409  1.0
  O  O38  1  0.682  0.186  0.591  1.0
  O  O39  1  0.186  0.682  0.409  1.0
  O  O40  1  0.504  0.318  0.591  1.0
  O  O41  1  0.814  0.496  0.591  1.0
  O  O42  1  0.318  0.500  0.055  1.0
  O  O43  1  0.500  0.819  0.055  1.0
  O  O44  1  0.682  0.181  0.945  1.0
  O  O45  1  0.181  0.682  0.055  1.0
  O  O46  1  0.500  0.318  0.945  1.0
  O  O47  1  0.819  0.500  0.945  1.0
[/CIF]
.
The material structure described by Sr4FeRh2O9 crystallizes in the trigonal P321 space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and four equivalent O(4) atoms. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one O(2), one O(4), two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms. In the third Sr site, Sr(3) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(5) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to three equivalent O(4) and three equivalent O(5) atoms to form distorted FeO6 pentagonal pyramids that share  a faceface with one Rh(1)O6 octahedra and  a faceface with one Rh(3)O6 octahedra. In the second Fe site, Fe(2) is bonded to six equivalent O(3) atoms to form distorted FeO6 pentagonal pyramids that share faces with two equivalent Rh(2)O6 octahedra. There are three inequivalent Rh sites. In the first Rh site, Rh(1) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form RhO6 octahedra that share  a faceface with one Rh(3)O6 octahedra and  a faceface with one Fe(1)O6 pentagonal pyramid. In the second Rh site, Rh(2) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form RhO6 octahedra that share  a faceface with one Rh(2)O6 octahedra and  a faceface with one Fe(2)O6 pentagonal pyramid. In the third Rh site, Rh(3) is bonded to three equivalent O(1) and three equivalent O(5) atoms to form RhO6 octahedra that share  a faceface with one Rh(1)O6 octahedra and  a faceface with one Fe(1)O6 pentagonal pyramid. There are five inequivalent O sites. In the first O site, O(4) is bonded in a 3-coordinate geometry to one Sr(2), two equivalent Sr(1), one Fe(1), and one Rh(1) atom. In the second O site, O(5) is bonded to two equivalent Sr(2), two equivalent Sr(3), one Fe(1), and one Rh(3) atom to form distorted OSr4FeRh octahedra that share corners with two equivalent O(2)Sr4Rh2 octahedra, corners with three equivalent O(5)Sr4FeRh octahedra, corners with three equivalent O(1)Sr4Rh2 octahedra,  an edgeedge with one O(1)Sr4Rh2 octahedra, faces with two equivalent O(1)Sr4Rh2 octahedra, and faces with three equivalent O(5)Sr4FeRh octahedra. The corner-sharing octahedral tilt angles range from 1-68°. In the third O site, O(1) is bonded to one Sr(1), one Sr(3), two equivalent Sr(2), one Rh(1), and one Rh(3) atom to form OSr4Rh2 octahedra that share corners with two equivalent O(1)Sr4Rh2 octahedra, corners with two equivalent O(2)Sr4Rh2 octahedra, corners with three equivalent O(5)Sr4FeRh octahedra,  an edgeedge with one O(5)Sr4FeRh octahedra,  an edgeedge with one O(2)Sr4Rh2 octahedra, faces with two equivalent O(5)Sr4FeRh octahedra, and faces with two equivalent O(1)Sr4Rh2 octahedra. The corner-sharing octahedral tilt angles range from 1-68°. In the fourth O site, O(2) is bonded to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Rh(2) atoms to form OSr4Rh2 octahedra that share corners with four equivalent O(5)Sr4FeRh octahedra, corners with four equivalent O(1)Sr4Rh2 octahedra, edges with two equivalent O(1)Sr4Rh2 octahedra, and faces with two equivalent O(2)Sr4Rh2 octahedra. The corner-sharing octahedral tilt angles range from 27-58°. In the fifth O site, O(3) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(3), two equivalent Sr(2), one Fe(2), and one Rh(2) atom. is represented by the CIF card [CIF]
data_Sr4FeRh2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.737
_cell_length_b   9.737
_cell_length_c   8.132
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   667.726
_cell_formula_units_Z   3
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  0.674  0.674  0.500  1.0
  Sr  Sr1  1  0.326  0.000  0.500  1.0
  Sr  Sr2  1  0.000  0.326  0.500  1.0
  Sr  Sr3  1  0.695  0.027  0.246  1.0
  Sr  Sr4  1  0.973  0.667  0.246  1.0
  Sr  Sr5  1  0.305  0.333  0.754  1.0
  Sr  Sr6  1  0.333  0.305  0.246  1.0
  Sr  Sr7  1  0.027  0.695  0.754  1.0
  Sr  Sr8  1  0.667  0.973  0.754  1.0
  Sr  Sr9  1  0.636  0.636  0.000  1.0
  Sr  Sr10  1  0.364  0.000  0.000  1.0
  Sr  Sr11  1  0.000  0.364  0.000  1.0
  Fe  Fe12  1  0.667  0.333  0.765  1.0
  Fe  Fe13  1  0.333  0.667  0.235  1.0
  Fe  Fe14  1  0.000  0.000  0.000  1.0
  Rh  Rh15  1  0.667  0.333  0.429  1.0
  Rh  Rh16  1  0.333  0.667  0.571  1.0
  Rh  Rh17  1  0.000  0.000  0.338  1.0
  Rh  Rh18  1  0.000  0.000  0.662  1.0
  Rh  Rh19  1  0.667  0.333  0.105  1.0
  Rh  Rh20  1  0.333  0.667  0.895  1.0
  O  O21  1  0.843  0.350  0.266  1.0
  O  O22  1  0.650  0.493  0.266  1.0
  O  O23  1  0.157  0.507  0.734  1.0
  O  O24  1  0.507  0.157  0.266  1.0
  O  O25  1  0.350  0.843  0.734  1.0
  O  O26  1  0.493  0.650  0.734  1.0
  O  O27  1  0.164  0.164  0.500  1.0
  O  O28  1  0.836  0.000  0.500  1.0
  O  O29  1  0.000  0.836  0.500  1.0
  O  O30  1  0.007  0.162  0.176  1.0
  O  O31  1  0.838  0.845  0.176  1.0
  O  O32  1  0.993  0.155  0.824  1.0
  O  O33  1  0.155  0.993  0.176  1.0
  O  O34  1  0.162  0.007  0.824  1.0
  O  O35  1  0.845  0.838  0.824  1.0
  O  O36  1  0.318  0.504  0.409  1.0
  O  O37  1  0.496  0.814  0.409  1.0
  O  O38  1  0.682  0.186  0.591  1.0
  O  O39  1  0.186  0.682  0.409  1.0
  O  O40  1  0.504  0.318  0.591  1.0
  O  O41  1  0.814  0.496  0.591  1.0
  O  O42  1  0.318  0.500  0.055  1.0
  O  O43  1  0.500  0.819  0.055  1.0
  O  O44  1  0.682  0.181  0.945  1.0
  O  O45  1  0.181  0.682  0.055  1.0
  O  O46  1  0.500  0.318  0.945  1.0
  O  O47  1  0.819  0.500  0.945  1.0
[/CIF]
.