The material described by SrEu2Fe2O7 crystallizes in the tetragonal P4_2/mnm space group. Sr(1) is bonded to two equivalent O(2), two equivalent O(4), four equivalent O(3), and four equivalent O(5) atoms to form distorted 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 7-coordinate geometry to one O(2), one O(4), two equivalent O(5), and three equivalent O(1) atoms. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), and two equivalent O(5) 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 7-24°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Eu(1) and one Fe(1) atom. In the second O site, O(2) is bonded to two equivalent Sr(1), two equivalent Eu(1), and two equivalent Fe(1) atoms to form a mixture of distorted face, corner, and edge-sharing OSr2Eu2Fe2 octahedra. The corner-sharing octahedral tilt angles are 60°. In the third O site, O(3) is bonded in a 6-coordinate geometry to four equivalent Sr(1) and two equivalent Fe(1) atoms. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Sr(1), two equivalent Eu(1), and two equivalent Fe(1) atoms. In the fifth O site, O(5) is bonded to two equivalent Sr(1), two equivalent Eu(1), and two equivalent Fe(1) atoms to form a mixture of distorted face, corner, and edge-sharing OSr2Eu2Fe2 octahedra. The corner-sharing octahedral tilt angles range from 2-60°. is represented by the CIF card [CIF]
data_SrEu2Fe2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.588
_cell_length_b   5.588
_cell_length_c   20.012
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   624.817
_cell_formula_units_Z   4
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  0.255  0.745  0.500  1.0
  Sr  Sr1  1  0.755  0.755  0.000  1.0
  Sr  Sr2  1  0.745  0.255  0.500  1.0
  Sr  Sr3  1  0.245  0.245  0.000  1.0
  Eu  Eu4  1  0.271  0.729  0.316  1.0
  Eu  Eu5  1  0.271  0.729  0.684  1.0
  Eu  Eu6  1  0.729  0.271  0.684  1.0
  Eu  Eu7  1  0.771  0.771  0.184  1.0
  Eu  Eu8  1  0.229  0.229  0.184  1.0
  Eu  Eu9  1  0.729  0.271  0.316  1.0
  Eu  Eu10  1  0.771  0.771  0.816  1.0
  Eu  Eu11  1  0.229  0.229  0.816  1.0
  Fe  Fe12  1  0.246  0.246  0.401  1.0
  Fe  Fe13  1  0.254  0.746  0.901  1.0
  Fe  Fe14  1  0.746  0.254  0.901  1.0
  Fe  Fe15  1  0.246  0.246  0.599  1.0
  Fe  Fe16  1  0.754  0.754  0.599  1.0
  Fe  Fe17  1  0.254  0.746  0.099  1.0
  Fe  Fe18  1  0.746  0.254  0.099  1.0
  Fe  Fe19  1  0.754  0.754  0.401  1.0
  O  O20  1  0.702  0.702  0.296  1.0
  O  O21  1  0.500  0.500  0.411  1.0
  O  O22  1  0.713  0.287  0.000  1.0
  O  O23  1  0.798  0.202  0.796  1.0
  O  O24  1  0.500  0.500  0.120  1.0
  O  O25  1  0.202  0.798  0.204  1.0
  O  O26  1  0.202  0.798  0.796  1.0
  O  O27  1  0.500  0.500  0.589  1.0
  O  O28  1  0.287  0.713  0.000  1.0
  O  O29  1  0.000  0.500  0.895  1.0
  O  O30  1  0.000  0.000  0.620  1.0
  O  O31  1  0.213  0.213  0.500  1.0
  O  O32  1  0.000  0.000  0.089  1.0
  O  O33  1  0.000  0.000  0.911  1.0
  O  O34  1  0.500  0.000  0.605  1.0
  O  O35  1  0.798  0.202  0.204  1.0
  O  O36  1  0.298  0.298  0.704  1.0
  O  O37  1  0.000  0.500  0.605  1.0
  O  O38  1  0.298  0.298  0.296  1.0
  O  O39  1  0.500  0.000  0.105  1.0
  O  O40  1  0.500  0.500  0.880  1.0
  O  O41  1  0.500  0.000  0.395  1.0
  O  O42  1  0.000  0.000  0.380  1.0
  O  O43  1  0.000  0.500  0.105  1.0
  O  O44  1  0.702  0.702  0.704  1.0
  O  O45  1  0.787  0.787  0.500  1.0
  O  O46  1  0.000  0.500  0.395  1.0
  O  O47  1  0.500  0.000  0.895  1.0
[/CIF]
.
The material described by SrEu2Fe2O7 crystallizes in the tetragonal P4_2/mnm space group. Sr(1) is bonded to two equivalent O(2), two equivalent O(4), four equivalent O(3), and four equivalent O(5) atoms to form distorted 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 7-coordinate geometry to one O(2), one O(4), two equivalent O(5), and three equivalent O(1) atoms. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), and two equivalent O(5) 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 7-24°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Eu(1) and one Fe(1) atom. In the second O site, O(2) is bonded to two equivalent Sr(1), two equivalent Eu(1), and two equivalent Fe(1) atoms to form a mixture of distorted face, corner, and edge-sharing OSr2Eu2Fe2 octahedra. The corner-sharing octahedral tilt angles are 60°. In the third O site, O(3) is bonded in a 6-coordinate geometry to four equivalent Sr(1) and two equivalent Fe(1) atoms. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Sr(1), two equivalent Eu(1), and two equivalent Fe(1) atoms. In the fifth O site, O(5) is bonded to two equivalent Sr(1), two equivalent Eu(1), and two equivalent Fe(1) atoms to form a mixture of distorted face, corner, and edge-sharing OSr2Eu2Fe2 octahedra. The corner-sharing octahedral tilt angles range from 2-60°. is represented by the CIF card [CIF]
data_SrEu2Fe2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.588
_cell_length_b   5.588
_cell_length_c   20.012
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   624.817
_cell_formula_units_Z   4
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  0.255  0.745  0.500  1.0
  Sr  Sr1  1  0.755  0.755  0.000  1.0
  Sr  Sr2  1  0.745  0.255  0.500  1.0
  Sr  Sr3  1  0.245  0.245  0.000  1.0
  Eu  Eu4  1  0.271  0.729  0.316  1.0
  Eu  Eu5  1  0.271  0.729  0.684  1.0
  Eu  Eu6  1  0.729  0.271  0.684  1.0
  Eu  Eu7  1  0.771  0.771  0.184  1.0
  Eu  Eu8  1  0.229  0.229  0.184  1.0
  Eu  Eu9  1  0.729  0.271  0.316  1.0
  Eu  Eu10  1  0.771  0.771  0.816  1.0
  Eu  Eu11  1  0.229  0.229  0.816  1.0
  Fe  Fe12  1  0.246  0.246  0.401  1.0
  Fe  Fe13  1  0.254  0.746  0.901  1.0
  Fe  Fe14  1  0.746  0.254  0.901  1.0
  Fe  Fe15  1  0.246  0.246  0.599  1.0
  Fe  Fe16  1  0.754  0.754  0.599  1.0
  Fe  Fe17  1  0.254  0.746  0.099  1.0
  Fe  Fe18  1  0.746  0.254  0.099  1.0
  Fe  Fe19  1  0.754  0.754  0.401  1.0
  O  O20  1  0.702  0.702  0.296  1.0
  O  O21  1  0.500  0.500  0.411  1.0
  O  O22  1  0.713  0.287  0.000  1.0
  O  O23  1  0.798  0.202  0.796  1.0
  O  O24  1  0.500  0.500  0.120  1.0
  O  O25  1  0.202  0.798  0.204  1.0
  O  O26  1  0.202  0.798  0.796  1.0
  O  O27  1  0.500  0.500  0.589  1.0
  O  O28  1  0.287  0.713  0.000  1.0
  O  O29  1  0.000  0.500  0.895  1.0
  O  O30  1  0.000  0.000  0.620  1.0
  O  O31  1  0.213  0.213  0.500  1.0
  O  O32  1  0.000  0.000  0.089  1.0
  O  O33  1  0.000  0.000  0.911  1.0
  O  O34  1  0.500  0.000  0.605  1.0
  O  O35  1  0.798  0.202  0.204  1.0
  O  O36  1  0.298  0.298  0.704  1.0
  O  O37  1  0.000  0.500  0.605  1.0
  O  O38  1  0.298  0.298  0.296  1.0
  O  O39  1  0.500  0.000  0.105  1.0
  O  O40  1  0.500  0.500  0.880  1.0
  O  O41  1  0.500  0.000  0.395  1.0
  O  O42  1  0.000  0.000  0.380  1.0
  O  O43  1  0.000  0.500  0.105  1.0
  O  O44  1  0.702  0.702  0.704  1.0
  O  O45  1  0.787  0.787  0.500  1.0
  O  O46  1  0.000  0.500  0.395  1.0
  O  O47  1  0.500  0.000  0.895  1.0
[/CIF]
.