The compound described by Sr2Ti2O5 crystallizes in the orthorhombic Ima2 space group. Sr(1) is bonded in a 9-coordinate geometry to one O(3), four equivalent O(1), and four equivalent O(2) atoms. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form TiO6 octahedra that share corners with four equivalent Ti(1)O6 octahedra and corners with two equivalent Ti(2)O4 trigonal pyramids. The corner-sharing octahedral tilt angles are 5°. In the second Ti site, Ti(2) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form TiO4 trigonal pyramids that share corners with two equivalent Ti(1)O6 octahedra and corners with two equivalent Ti(2)O4 trigonal pyramids. The corner-sharing octahedral tilt angles are 17°. There are three inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Sr(1) and two equivalent Ti(1) atoms to form a mixture of distorted corner, edge, and face-sharing OSr4Ti2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded in a 6-coordinate geometry to four equivalent Sr(1), one Ti(1), and one Ti(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Sr(1) and two equivalent Ti(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sr2Ti2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.875
_cell_length_b   8.875
_cell_length_c   8.875
_cell_angle_alpha   142.884
_cell_angle_beta   142.694
_cell_angle_gamma   53.642
_symmetry_Int_Tables_number   1
_cell_volume   254.029
_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  0.899  0.391  0.515  1.0
  Sr  Sr1  1  0.101  0.616  0.492  1.0
  Sr  Sr2  1  0.376  0.891  0.492  1.0
  Sr  Sr3  1  0.624  0.116  0.515  1.0
  Ti  Ti4  1  0.000  0.004  0.004  1.0
  Ti  Ti5  1  0.500  0.504  0.004  1.0
  Ti  Ti6  1  0.711  0.727  0.938  1.0
  Ti  Ti7  1  0.289  0.227  0.016  1.0
  O  O8  1  0.256  0.258  0.503  1.0
  O  O9  1  0.744  0.247  0.002  1.0
  O  O10  1  0.255  0.758  0.002  1.0
  O  O11  1  0.745  0.747  0.503  1.0
  O  O12  1  0.898  0.871  0.031  1.0
  O  O13  1  0.102  0.133  0.973  1.0
  O  O14  1  0.340  0.371  0.973  1.0
  O  O15  1  0.660  0.633  0.031  1.0
  O  O16  1  0.573  0.416  0.489  1.0
  O  O17  1  0.427  0.916  0.844  1.0
[/CIF]
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The compound described by Sr2Ti2O5 crystallizes in the orthorhombic Ima2 space group. Sr(1) is bonded in a 9-coordinate geometry to one O(3), four equivalent O(1), and four equivalent O(2) atoms. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form TiO6 octahedra that share corners with four equivalent Ti(1)O6 octahedra and corners with two equivalent Ti(2)O4 trigonal pyramids. The corner-sharing octahedral tilt angles are 5°. In the second Ti site, Ti(2) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form TiO4 trigonal pyramids that share corners with two equivalent Ti(1)O6 octahedra and corners with two equivalent Ti(2)O4 trigonal pyramids. The corner-sharing octahedral tilt angles are 17°. There are three inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Sr(1) and two equivalent Ti(1) atoms to form a mixture of distorted corner, edge, and face-sharing OSr4Ti2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded in a 6-coordinate geometry to four equivalent Sr(1), one Ti(1), and one Ti(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Sr(1) and two equivalent Ti(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sr2Ti2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.875
_cell_length_b   8.875
_cell_length_c   8.875
_cell_angle_alpha   142.884
_cell_angle_beta   142.694
_cell_angle_gamma   53.642
_symmetry_Int_Tables_number   1
_cell_volume   254.029
_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  0.899  0.391  0.515  1.0
  Sr  Sr1  1  0.101  0.616  0.492  1.0
  Sr  Sr2  1  0.376  0.891  0.492  1.0
  Sr  Sr3  1  0.624  0.116  0.515  1.0
  Ti  Ti4  1  0.000  0.004  0.004  1.0
  Ti  Ti5  1  0.500  0.504  0.004  1.0
  Ti  Ti6  1  0.711  0.727  0.938  1.0
  Ti  Ti7  1  0.289  0.227  0.016  1.0
  O  O8  1  0.256  0.258  0.503  1.0
  O  O9  1  0.744  0.247  0.002  1.0
  O  O10  1  0.255  0.758  0.002  1.0
  O  O11  1  0.745  0.747  0.503  1.0
  O  O12  1  0.898  0.871  0.031  1.0
  O  O13  1  0.102  0.133  0.973  1.0
  O  O14  1  0.340  0.371  0.973  1.0
  O  O15  1  0.660  0.633  0.031  1.0
  O  O16  1  0.573  0.416  0.489  1.0
  O  O17  1  0.427  0.916  0.844  1.0
[/CIF]
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