The material structure described by Sr2Y2Ti2O7 crystallizes in the orthorhombic Ima2 space group. Sr(1) is bonded in a 9-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), and four equivalent O(4) atoms. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a body-centered cubic geometry to four equivalent O(2) and four equivalent O(3) atoms. In the second Y site, Y(2) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form distorted corner-sharing YO4 tetrahedra. Ti(1) is bonded in a distorted rectangular see-saw-like geometry to one O(4), two equivalent O(2), and two equivalent O(3) atoms. There are four inequivalent O sites. In the first O site, O(4) is bonded in a 6-coordinate geometry to four equivalent Sr(1), one Y(2), and one Ti(1) atom. In the second O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sr(1) and two equivalent Y(2) atoms. In the third O site, O(2) is bonded to two equivalent Sr(1), two equivalent Y(1), and two equivalent Ti(1) atoms to form a mixture of distorted edge, face, and corner-sharing OSr2Y2Ti2 octahedra. The corner-sharing octahedral tilt angles range from 1-68°. In the fourth O site, O(3) is bonded to two equivalent Sr(1), two equivalent Y(1), and two equivalent Ti(1) atoms to form a mixture of distorted edge, face, and corner-sharing OSr2Y2Ti2 octahedra. The corner-sharing octahedral tilt angles range from 1-68°. is represented by the CIF file [CIF]
data_Sr2Y2Ti2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.979
_cell_length_b   12.979
_cell_length_c   12.979
_cell_angle_alpha   155.398
_cell_angle_beta   155.159
_cell_angle_gamma   35.244
_symmetry_Int_Tables_number   1
_cell_volume   381.970
_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  0.834  0.837  0.961  1.0
  Sr  Sr1  1  0.166  0.128  0.004  1.0
  Sr  Sr2  1  0.624  0.628  0.961  1.0
  Sr  Sr3  1  0.376  0.337  0.004  1.0
  Y  Y4  1  0.500  0.472  0.972  1.0
  Y  Y5  1  0.000  0.972  0.972  1.0
  Y  Y6  1  0.204  0.766  0.470  1.0
  Y  Y7  1  0.796  0.266  0.562  1.0
  Ti  Ti8  1  0.943  0.414  0.473  1.0
  Ti  Ti9  1  0.057  0.530  0.471  1.0
  Ti  Ti10  1  0.559  0.030  0.473  1.0
  Ti  Ti11  1  0.441  0.914  0.471  1.0
  O  O12  1  0.823  0.666  0.989  1.0
  O  O13  1  0.177  0.166  0.843  1.0
  O  O14  1  0.692  0.664  0.482  1.0
  O  O15  1  0.308  0.790  0.972  1.0
  O  O16  1  0.319  0.290  0.482  1.0
  O  O17  1  0.681  0.164  0.972  1.0
  O  O18  1  0.182  0.153  0.464  1.0
  O  O19  1  0.818  0.282  0.972  1.0
  O  O20  1  0.810  0.782  0.464  1.0
  O  O21  1  0.190  0.653  0.972  1.0
  O  O22  1  0.375  0.772  0.481  1.0
  O  O23  1  0.625  0.106  0.398  1.0
  O  O24  1  0.208  0.606  0.481  1.0
  O  O25  1  0.792  0.272  0.398  1.0
[/CIF]
.
The material structure described by Sr2Y2Ti2O7 crystallizes in the orthorhombic Ima2 space group. Sr(1) is bonded in a 9-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), and four equivalent O(4) atoms. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a body-centered cubic geometry to four equivalent O(2) and four equivalent O(3) atoms. In the second Y site, Y(2) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form distorted corner-sharing YO4 tetrahedra. Ti(1) is bonded in a distorted rectangular see-saw-like geometry to one O(4), two equivalent O(2), and two equivalent O(3) atoms. There are four inequivalent O sites. In the first O site, O(4) is bonded in a 6-coordinate geometry to four equivalent Sr(1), one Y(2), and one Ti(1) atom. In the second O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sr(1) and two equivalent Y(2) atoms. In the third O site, O(2) is bonded to two equivalent Sr(1), two equivalent Y(1), and two equivalent Ti(1) atoms to form a mixture of distorted edge, face, and corner-sharing OSr2Y2Ti2 octahedra. The corner-sharing octahedral tilt angles range from 1-68°. In the fourth O site, O(3) is bonded to two equivalent Sr(1), two equivalent Y(1), and two equivalent Ti(1) atoms to form a mixture of distorted edge, face, and corner-sharing OSr2Y2Ti2 octahedra. The corner-sharing octahedral tilt angles range from 1-68°. is represented by the CIF file [CIF]
data_Sr2Y2Ti2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.979
_cell_length_b   12.979
_cell_length_c   12.979
_cell_angle_alpha   155.398
_cell_angle_beta   155.159
_cell_angle_gamma   35.244
_symmetry_Int_Tables_number   1
_cell_volume   381.970
_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  0.834  0.837  0.961  1.0
  Sr  Sr1  1  0.166  0.128  0.004  1.0
  Sr  Sr2  1  0.624  0.628  0.961  1.0
  Sr  Sr3  1  0.376  0.337  0.004  1.0
  Y  Y4  1  0.500  0.472  0.972  1.0
  Y  Y5  1  0.000  0.972  0.972  1.0
  Y  Y6  1  0.204  0.766  0.470  1.0
  Y  Y7  1  0.796  0.266  0.562  1.0
  Ti  Ti8  1  0.943  0.414  0.473  1.0
  Ti  Ti9  1  0.057  0.530  0.471  1.0
  Ti  Ti10  1  0.559  0.030  0.473  1.0
  Ti  Ti11  1  0.441  0.914  0.471  1.0
  O  O12  1  0.823  0.666  0.989  1.0
  O  O13  1  0.177  0.166  0.843  1.0
  O  O14  1  0.692  0.664  0.482  1.0
  O  O15  1  0.308  0.790  0.972  1.0
  O  O16  1  0.319  0.290  0.482  1.0
  O  O17  1  0.681  0.164  0.972  1.0
  O  O18  1  0.182  0.153  0.464  1.0
  O  O19  1  0.818  0.282  0.972  1.0
  O  O20  1  0.810  0.782  0.464  1.0
  O  O21  1  0.190  0.653  0.972  1.0
  O  O22  1  0.375  0.772  0.481  1.0
  O  O23  1  0.625  0.106  0.398  1.0
  O  O24  1  0.208  0.606  0.481  1.0
  O  O25  1  0.792  0.272  0.398  1.0
[/CIF]
.