The crystal structure described by SrEu2Fe2O7 crystallizes in the orthorhombic Cmcm space group. Sr(1) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms to form SrO12 cuboctahedra that share corners with four equivalent Sr(1)O12 cuboctahedra, faces with four equivalent Sr(1)O12 cuboctahedra, and faces with eight equivalent Fe(1)O6 octahedra. Eu(1) is bonded in a 9-coordinate geometry to two equivalent O(2), two equivalent O(3), and five equivalent O(4) atoms. Fe(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share corners with five equivalent Fe(1)O6 octahedra and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-7°. There are four inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Sr(1) and two equivalent Fe(1) atoms to form distorted OSr4Fe2 octahedra that share corners with two equivalent O(4)Eu5Fe octahedra, corners with four equivalent O(1)Sr4Fe2 octahedra, corners with eight equivalent O(3)Sr2Eu2Fe2 octahedra, edges with four equivalent O(1)Sr4Fe2 octahedra, and faces with four equivalent O(3)Sr2Eu2Fe2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Eu(1), and two equivalent Fe(1) atoms. In the third O site, O(3) is bonded to two equivalent Sr(1), two equivalent Eu(1), and two equivalent Fe(1) atoms to form distorted OSr2Eu2Fe2 octahedra that share corners with two equivalent O(3)Sr2Eu2Fe2 octahedra, corners with four equivalent O(1)Sr4Fe2 octahedra, corners with six equivalent O(4)Eu5Fe octahedra,  an edgeedge with one O(3)Sr2Eu2Fe2 octahedra, faces with two equivalent O(4)Eu5Fe octahedra, faces with two equivalent O(3)Sr2Eu2Fe2 octahedra, and faces with two equivalent O(1)Sr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 45-60°. In the fourth O site, O(4) is bonded to five equivalent Eu(1) and one Fe(1) atom to form distorted OEu5Fe octahedra that share  a cornercorner with one O(1)Sr4Fe2 octahedra, corners with four equivalent O(4)Eu5Fe octahedra, corners with six equivalent O(3)Sr2Eu2Fe2 octahedra, edges with eight equivalent O(4)Eu5Fe octahedra, and faces with two equivalent O(3)Sr2Eu2Fe2 octahedra. The corner-sharing octahedral tilt angles range from 1-54°. is represented by the CIF file [CIF]
data_SrEu2Fe2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.427
_cell_length_b   5.427
_cell_length_c   10.383
_cell_angle_alpha   90.000
_cell_angle_beta   74.851
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   295.129
_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
  Sr  Sr0  1  0.248  0.250  0.000  1.0
  Sr  Sr1  1  0.752  0.750  0.000  1.0
  Eu  Eu2  1  0.059  0.250  0.367  1.0
  Eu  Eu3  1  0.574  0.750  0.367  1.0
  Eu  Eu4  1  0.426  0.250  0.633  1.0
  Eu  Eu5  1  0.941  0.750  0.633  1.0
  Fe  Fe6  1  0.846  0.250  0.807  1.0
  Fe  Fe7  1  0.348  0.750  0.807  1.0
  Fe  Fe8  1  0.652  0.250  0.193  1.0
  Fe  Fe9  1  0.154  0.750  0.193  1.0
  O  O10  1  0.737  0.250  0.000  1.0
  O  O11  1  0.263  0.750  0.000  1.0
  O  O12  1  0.603  0.000  0.794  1.0
  O  O13  1  0.603  0.500  0.794  1.0
  O  O14  1  0.397  0.500  0.206  1.0
  O  O15  1  0.397  0.000  0.206  1.0
  O  O16  1  0.903  0.000  0.194  1.0
  O  O17  1  0.903  0.500  0.194  1.0
  O  O18  1  0.097  0.500  0.806  1.0
  O  O19  1  0.097  0.000  0.806  1.0
  O  O20  1  0.969  0.250  0.600  1.0
  O  O21  1  0.431  0.750  0.600  1.0
  O  O22  1  0.569  0.250  0.400  1.0
  O  O23  1  0.031  0.750  0.400  1.0
[/CIF]
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The crystal structure described by SrEu2Fe2O7 crystallizes in the orthorhombic Cmcm space group. Sr(1) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(3) atoms to form SrO12 cuboctahedra that share corners with four equivalent Sr(1)O12 cuboctahedra, faces with four equivalent Sr(1)O12 cuboctahedra, and faces with eight equivalent Fe(1)O6 octahedra. Eu(1) is bonded in a 9-coordinate geometry to two equivalent O(2), two equivalent O(3), and five equivalent O(4) atoms. Fe(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share corners with five equivalent Fe(1)O6 octahedra and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-7°. There are four inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Sr(1) and two equivalent Fe(1) atoms to form distorted OSr4Fe2 octahedra that share corners with two equivalent O(4)Eu5Fe octahedra, corners with four equivalent O(1)Sr4Fe2 octahedra, corners with eight equivalent O(3)Sr2Eu2Fe2 octahedra, edges with four equivalent O(1)Sr4Fe2 octahedra, and faces with four equivalent O(3)Sr2Eu2Fe2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Eu(1), and two equivalent Fe(1) atoms. In the third O site, O(3) is bonded to two equivalent Sr(1), two equivalent Eu(1), and two equivalent Fe(1) atoms to form distorted OSr2Eu2Fe2 octahedra that share corners with two equivalent O(3)Sr2Eu2Fe2 octahedra, corners with four equivalent O(1)Sr4Fe2 octahedra, corners with six equivalent O(4)Eu5Fe octahedra,  an edgeedge with one O(3)Sr2Eu2Fe2 octahedra, faces with two equivalent O(4)Eu5Fe octahedra, faces with two equivalent O(3)Sr2Eu2Fe2 octahedra, and faces with two equivalent O(1)Sr4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 45-60°. In the fourth O site, O(4) is bonded to five equivalent Eu(1) and one Fe(1) atom to form distorted OEu5Fe octahedra that share  a cornercorner with one O(1)Sr4Fe2 octahedra, corners with four equivalent O(4)Eu5Fe octahedra, corners with six equivalent O(3)Sr2Eu2Fe2 octahedra, edges with eight equivalent O(4)Eu5Fe octahedra, and faces with two equivalent O(3)Sr2Eu2Fe2 octahedra. The corner-sharing octahedral tilt angles range from 1-54°. is represented by the CIF file [CIF]
data_SrEu2Fe2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.427
_cell_length_b   5.427
_cell_length_c   10.383
_cell_angle_alpha   90.000
_cell_angle_beta   74.851
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   295.129
_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
  Sr  Sr0  1  0.248  0.250  0.000  1.0
  Sr  Sr1  1  0.752  0.750  0.000  1.0
  Eu  Eu2  1  0.059  0.250  0.367  1.0
  Eu  Eu3  1  0.574  0.750  0.367  1.0
  Eu  Eu4  1  0.426  0.250  0.633  1.0
  Eu  Eu5  1  0.941  0.750  0.633  1.0
  Fe  Fe6  1  0.846  0.250  0.807  1.0
  Fe  Fe7  1  0.348  0.750  0.807  1.0
  Fe  Fe8  1  0.652  0.250  0.193  1.0
  Fe  Fe9  1  0.154  0.750  0.193  1.0
  O  O10  1  0.737  0.250  0.000  1.0
  O  O11  1  0.263  0.750  0.000  1.0
  O  O12  1  0.603  0.000  0.794  1.0
  O  O13  1  0.603  0.500  0.794  1.0
  O  O14  1  0.397  0.500  0.206  1.0
  O  O15  1  0.397  0.000  0.206  1.0
  O  O16  1  0.903  0.000  0.194  1.0
  O  O17  1  0.903  0.500  0.194  1.0
  O  O18  1  0.097  0.500  0.806  1.0
  O  O19  1  0.097  0.000  0.806  1.0
  O  O20  1  0.969  0.250  0.600  1.0
  O  O21  1  0.431  0.750  0.600  1.0
  O  O22  1  0.569  0.250  0.400  1.0
  O  O23  1  0.031  0.750  0.400  1.0
[/CIF]
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