The structure described by Sr2YFe2AlO7 crystallizes in the orthorhombic Ima2 space group. Sr(1) is bonded in a 5-coordinate geometry to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms. Y(1) is bonded in a 8-coordinate geometry to four equivalent O(2) and four equivalent O(3) atoms. Fe(1) is bonded to one O(4), two equivalent O(2), and two equivalent O(3) atoms to form distorted FeO5 trigonal bipyramids that share  a cornercorner with one Al(1)O4 tetrahedra and corners with four equivalent Fe(1)O5 trigonal bipyramids. Al(1) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form AlO4 tetrahedra that share corners with two equivalent Al(1)O4 tetrahedra and corners with two equivalent Fe(1)O5 trigonal bipyramids. There are four inequivalent O sites. In the first O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Sr(1), one Fe(1), and one Al(1) atom. In the second O site, O(1) is bonded to two equivalent Sr(1) and two equivalent Al(1) atoms to form distorted corner-sharing OSr2Al2 tetrahedra. In the third O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Y(1), and two equivalent Fe(1) atoms. In the fourth O site, O(3) is bonded in a 4-coordinate geometry to one Sr(1), two equivalent Y(1), and two equivalent Fe(1) atoms. is represented by the CIF card [CIF]
data_Sr2YAlFe2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.774
_cell_length_b   11.774
_cell_length_c   11.774
_cell_angle_alpha   152.487
_cell_angle_beta   151.180
_cell_angle_gamma   40.266
_symmetry_Int_Tables_number   1
_cell_volume   362.735
_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  0.815  0.834  0.961  1.0
  Sr  Sr1  1  0.185  0.146  0.019  1.0
  Sr  Sr2  1  0.626  0.646  0.961  1.0
  Sr  Sr3  1  0.374  0.334  0.019  1.0
  Y  Y4  1  0.500  0.497  0.997  1.0
  Y  Y5  1  0.000  0.997  0.997  1.0
  Al  Al6  1  0.171  0.753  0.424  1.0
  Al  Al7  1  0.829  0.253  0.582  1.0
  Fe  Fe8  1  0.925  0.406  0.494  1.0
  Fe  Fe9  1  0.075  0.570  0.481  1.0
  Fe  Fe10  1  0.589  0.070  0.494  1.0
  Fe  Fe11  1  0.411  0.906  0.481  1.0
  O  O12  1  0.921  0.563  0.983  1.0
  O  O13  1  0.079  0.063  0.642  1.0
  O  O14  1  0.737  0.698  0.564  1.0
  O  O15  1  0.263  0.827  0.962  1.0
  O  O16  1  0.366  0.327  0.564  1.0
  O  O17  1  0.634  0.198  0.962  1.0
  O  O18  1  0.126  0.123  0.392  1.0
  O  O19  1  0.874  0.266  0.996  1.0
  O  O20  1  0.769  0.766  0.392  1.0
  O  O21  1  0.231  0.623  0.996  1.0
  O  O22  1  0.382  0.768  0.512  1.0
  O  O23  1  0.618  0.130  0.386  1.0
  O  O24  1  0.244  0.630  0.512  1.0
  O  O25  1  0.756  0.268  0.386  1.0
[/CIF]
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The structure described by Sr2YFe2AlO7 crystallizes in the orthorhombic Ima2 space group. Sr(1) is bonded in a 5-coordinate geometry to one O(1), one O(3), two equivalent O(2), and two equivalent O(4) atoms. Y(1) is bonded in a 8-coordinate geometry to four equivalent O(2) and four equivalent O(3) atoms. Fe(1) is bonded to one O(4), two equivalent O(2), and two equivalent O(3) atoms to form distorted FeO5 trigonal bipyramids that share  a cornercorner with one Al(1)O4 tetrahedra and corners with four equivalent Fe(1)O5 trigonal bipyramids. Al(1) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form AlO4 tetrahedra that share corners with two equivalent Al(1)O4 tetrahedra and corners with two equivalent Fe(1)O5 trigonal bipyramids. There are four inequivalent O sites. In the first O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Sr(1), one Fe(1), and one Al(1) atom. In the second O site, O(1) is bonded to two equivalent Sr(1) and two equivalent Al(1) atoms to form distorted corner-sharing OSr2Al2 tetrahedra. In the third O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Y(1), and two equivalent Fe(1) atoms. In the fourth O site, O(3) is bonded in a 4-coordinate geometry to one Sr(1), two equivalent Y(1), and two equivalent Fe(1) atoms. is represented by the CIF card [CIF]
data_Sr2YAlFe2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.774
_cell_length_b   11.774
_cell_length_c   11.774
_cell_angle_alpha   152.487
_cell_angle_beta   151.180
_cell_angle_gamma   40.266
_symmetry_Int_Tables_number   1
_cell_volume   362.735
_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  0.815  0.834  0.961  1.0
  Sr  Sr1  1  0.185  0.146  0.019  1.0
  Sr  Sr2  1  0.626  0.646  0.961  1.0
  Sr  Sr3  1  0.374  0.334  0.019  1.0
  Y  Y4  1  0.500  0.497  0.997  1.0
  Y  Y5  1  0.000  0.997  0.997  1.0
  Al  Al6  1  0.171  0.753  0.424  1.0
  Al  Al7  1  0.829  0.253  0.582  1.0
  Fe  Fe8  1  0.925  0.406  0.494  1.0
  Fe  Fe9  1  0.075  0.570  0.481  1.0
  Fe  Fe10  1  0.589  0.070  0.494  1.0
  Fe  Fe11  1  0.411  0.906  0.481  1.0
  O  O12  1  0.921  0.563  0.983  1.0
  O  O13  1  0.079  0.063  0.642  1.0
  O  O14  1  0.737  0.698  0.564  1.0
  O  O15  1  0.263  0.827  0.962  1.0
  O  O16  1  0.366  0.327  0.564  1.0
  O  O17  1  0.634  0.198  0.962  1.0
  O  O18  1  0.126  0.123  0.392  1.0
  O  O19  1  0.874  0.266  0.996  1.0
  O  O20  1  0.769  0.766  0.392  1.0
  O  O21  1  0.231  0.623  0.996  1.0
  O  O22  1  0.382  0.768  0.512  1.0
  O  O23  1  0.618  0.130  0.386  1.0
  O  O24  1  0.244  0.630  0.512  1.0
  O  O25  1  0.756  0.268  0.386  1.0
[/CIF]
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