The crystal structure described by TlSr4Fe2O9 crystallizes in the orthorhombic Fmm2 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one O(4), four equivalent O(1), and four equivalent O(2) atoms. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to four equivalent O(2) and five equivalent O(3) atoms. Fe(1) is bonded to one O(1), one O(3), and four equivalent O(2) atoms to form distorted FeO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra and  a cornercorner with one Tl(1)O5 square pyramid. The corner-sharing octahedral tilt angles are 10°. Tl(1) is bonded to two equivalent O(1) and three equivalent O(4) atoms to form distorted TlO5 square pyramids that share corners with two equivalent Fe(1)O6 octahedra and corners with six equivalent Tl(1)O5 square pyramids. The corner-sharing octahedral tilt angles are 6°. There are four inequivalent O sites. In the first O site, O(3) is bonded to five equivalent Sr(2) and one Fe(1) atom to form distorted OSr5Fe octahedra that share  a cornercorner with one O(1)Sr4TlFe octahedra, corners with four equivalent O(3)Sr5Fe octahedra, corners with twelve equivalent O(2)Sr4Fe2 octahedra, edges with eight equivalent O(3)Sr5Fe octahedra, and faces with four equivalent O(2)Sr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 1-56°. In the second O site, O(4) is bonded to two equivalent Sr(1) and three equivalent Tl(1) atoms to form distorted OSr2Tl3 square pyramids that share corners with two equivalent O(1)Sr4TlFe octahedra, corners with eight equivalent O(2)Sr4Fe2 octahedra, corners with six equivalent O(4)Sr2Tl3 square pyramids, and edges with six equivalent O(1)Sr4TlFe octahedra. The corner-sharing octahedral tilt angles range from 42-93°. In the third O site, O(1) is bonded to four equivalent Sr(1), one Fe(1), and one Tl(1) atom to form distorted OSr4TlFe octahedra that share  a cornercorner with one O(3)Sr5Fe octahedra, corners with five equivalent O(1)Sr4TlFe octahedra, corners with eight equivalent O(2)Sr4Fe2 octahedra,  a cornercorner with one O(4)Sr2Tl3 square pyramid, edges with four equivalent O(1)Sr4TlFe octahedra, edges with three equivalent O(4)Sr2Tl3 square pyramids, and faces with four equivalent O(2)Sr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 1-53°. In the fourth O site, O(2) is bonded to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Fe(1) atoms to form distorted OSr4Fe2 octahedra that share corners with two equivalent O(2)Sr4Fe2 octahedra, corners with four equivalent O(1)Sr4TlFe octahedra, corners with six equivalent O(3)Sr5Fe octahedra, corners with two equivalent O(4)Sr2Tl3 square pyramids, edges with two equivalent O(2)Sr4Fe2 octahedra, faces with two equivalent O(1)Sr4TlFe octahedra, faces with two equivalent O(3)Sr5Fe octahedra, and faces with four equivalent O(2)Sr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 10-56°. is represented by the CIF file [CIF]
data_Sr4TlFe2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   15.538
_cell_length_b   15.534
_cell_length_c   3.851
_cell_angle_alpha   82.943
_cell_angle_beta   82.817
_cell_angle_gamma   14.240
_symmetry_Int_Tables_number   1
_cell_volume   226.870
_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  0.582  0.582  0.418  1.0
  Sr  Sr1  1  0.418  0.418  0.582  1.0
  Sr  Sr2  1  0.705  0.705  0.295  1.0
  Sr  Sr3  1  0.295  0.295  0.705  1.0
  Tl  Tl4  1  0.027  0.973  0.027  1.0
  Fe  Fe5  1  0.148  0.149  0.851  1.0
  Fe  Fe6  1  0.851  0.852  0.148  1.0
  O  O7  1  0.063  0.075  0.925  1.0
  O  O8  1  0.925  0.937  0.063  1.0
  O  O9  1  0.643  0.643  0.857  1.0
  O  O10  1  0.143  0.143  0.357  1.0
  O  O11  1  0.357  0.357  0.143  1.0
  O  O12  1  0.857  0.857  0.643  1.0
  O  O13  1  0.213  0.213  0.787  1.0
  O  O14  1  0.787  0.787  0.213  1.0
  O  O15  1  0.456  0.544  0.456  1.0
[/CIF]
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The crystal structure described by TlSr4Fe2O9 crystallizes in the orthorhombic Fmm2 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one O(4), four equivalent O(1), and four equivalent O(2) atoms. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to four equivalent O(2) and five equivalent O(3) atoms. Fe(1) is bonded to one O(1), one O(3), and four equivalent O(2) atoms to form distorted FeO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra and  a cornercorner with one Tl(1)O5 square pyramid. The corner-sharing octahedral tilt angles are 10°. Tl(1) is bonded to two equivalent O(1) and three equivalent O(4) atoms to form distorted TlO5 square pyramids that share corners with two equivalent Fe(1)O6 octahedra and corners with six equivalent Tl(1)O5 square pyramids. The corner-sharing octahedral tilt angles are 6°. There are four inequivalent O sites. In the first O site, O(3) is bonded to five equivalent Sr(2) and one Fe(1) atom to form distorted OSr5Fe octahedra that share  a cornercorner with one O(1)Sr4TlFe octahedra, corners with four equivalent O(3)Sr5Fe octahedra, corners with twelve equivalent O(2)Sr4Fe2 octahedra, edges with eight equivalent O(3)Sr5Fe octahedra, and faces with four equivalent O(2)Sr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 1-56°. In the second O site, O(4) is bonded to two equivalent Sr(1) and three equivalent Tl(1) atoms to form distorted OSr2Tl3 square pyramids that share corners with two equivalent O(1)Sr4TlFe octahedra, corners with eight equivalent O(2)Sr4Fe2 octahedra, corners with six equivalent O(4)Sr2Tl3 square pyramids, and edges with six equivalent O(1)Sr4TlFe octahedra. The corner-sharing octahedral tilt angles range from 42-93°. In the third O site, O(1) is bonded to four equivalent Sr(1), one Fe(1), and one Tl(1) atom to form distorted OSr4TlFe octahedra that share  a cornercorner with one O(3)Sr5Fe octahedra, corners with five equivalent O(1)Sr4TlFe octahedra, corners with eight equivalent O(2)Sr4Fe2 octahedra,  a cornercorner with one O(4)Sr2Tl3 square pyramid, edges with four equivalent O(1)Sr4TlFe octahedra, edges with three equivalent O(4)Sr2Tl3 square pyramids, and faces with four equivalent O(2)Sr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 1-53°. In the fourth O site, O(2) is bonded to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Fe(1) atoms to form distorted OSr4Fe2 octahedra that share corners with two equivalent O(2)Sr4Fe2 octahedra, corners with four equivalent O(1)Sr4TlFe octahedra, corners with six equivalent O(3)Sr5Fe octahedra, corners with two equivalent O(4)Sr2Tl3 square pyramids, edges with two equivalent O(2)Sr4Fe2 octahedra, faces with two equivalent O(1)Sr4TlFe octahedra, faces with two equivalent O(3)Sr5Fe octahedra, and faces with four equivalent O(2)Sr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 10-56°. is represented by the CIF file [CIF]
data_Sr4TlFe2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   15.538
_cell_length_b   15.534
_cell_length_c   3.851
_cell_angle_alpha   82.943
_cell_angle_beta   82.817
_cell_angle_gamma   14.240
_symmetry_Int_Tables_number   1
_cell_volume   226.870
_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  0.582  0.582  0.418  1.0
  Sr  Sr1  1  0.418  0.418  0.582  1.0
  Sr  Sr2  1  0.705  0.705  0.295  1.0
  Sr  Sr3  1  0.295  0.295  0.705  1.0
  Tl  Tl4  1  0.027  0.973  0.027  1.0
  Fe  Fe5  1  0.148  0.149  0.851  1.0
  Fe  Fe6  1  0.851  0.852  0.148  1.0
  O  O7  1  0.063  0.075  0.925  1.0
  O  O8  1  0.925  0.937  0.063  1.0
  O  O9  1  0.643  0.643  0.857  1.0
  O  O10  1  0.143  0.143  0.357  1.0
  O  O11  1  0.357  0.357  0.143  1.0
  O  O12  1  0.857  0.857  0.643  1.0
  O  O13  1  0.213  0.213  0.787  1.0
  O  O14  1  0.787  0.787  0.213  1.0
  O  O15  1  0.456  0.544  0.456  1.0
[/CIF]
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