The material structure described by Ba3Ti2O7 crystallizes in the orthorhombic Fmm2 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to four equivalent O(2) and five equivalent O(1) atoms. In the second Ba site, Ba(2) is bonded to four equivalent O(3) and eight equivalent O(2) atoms to form BaO12 cuboctahedra that share corners with four equivalent Ba(2)O12 cuboctahedra, faces with four equivalent Ba(2)O12 cuboctahedra, and faces with eight equivalent Ti(1)O6 octahedra. Ti(1) is bonded to one O(1), one O(3), and four equivalent O(2) atoms to form TiO6 octahedra that share corners with five equivalent Ti(1)O6 octahedra and faces with four equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 5-8°. There are three inequivalent O sites. In the first O site, O(1) is bonded to five equivalent Ba(1) and one Ti(1) atom to form a mixture of distorted corner and edge-sharing OBa5Ti octahedra. The corner-sharing octahedral tilt angles are 3°. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Ti(1) atoms. In the third O site, O(3) is bonded in a distorted linear geometry to four equivalent Ba(2) and two equivalent Ti(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba3Ti2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.110
_cell_length_b   11.107
_cell_length_c   4.070
_cell_angle_alpha   79.483
_cell_angle_beta   79.405
_cell_angle_gamma   21.112
_symmetry_Int_Tables_number   1
_cell_volume   177.759
_cell_formula_units_Z   1
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
  Ba  Ba0  1  0.562  0.072  0.928  1.0
  Ba  Ba1  1  0.743  0.257  0.743  1.0
  Ba  Ba2  1  0.928  0.438  0.562  1.0
  Ti  Ti3  1  0.135  0.676  0.324  1.0
  Ti  Ti4  1  0.324  0.865  0.135  1.0
  O  O5  1  0.069  0.560  0.440  1.0
  O  O6  1  0.158  0.654  0.858  1.0
  O  O7  1  0.858  0.331  0.158  1.0
  O  O8  1  0.346  0.842  0.669  1.0
  O  O9  1  0.669  0.142  0.346  1.0
  O  O10  1  0.255  0.745  0.255  1.0
  O  O11  1  0.440  0.931  0.069  1.0
[/CIF]
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The material structure described by Ba3Ti2O7 crystallizes in the orthorhombic Fmm2 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to four equivalent O(2) and five equivalent O(1) atoms. In the second Ba site, Ba(2) is bonded to four equivalent O(3) and eight equivalent O(2) atoms to form BaO12 cuboctahedra that share corners with four equivalent Ba(2)O12 cuboctahedra, faces with four equivalent Ba(2)O12 cuboctahedra, and faces with eight equivalent Ti(1)O6 octahedra. Ti(1) is bonded to one O(1), one O(3), and four equivalent O(2) atoms to form TiO6 octahedra that share corners with five equivalent Ti(1)O6 octahedra and faces with four equivalent Ba(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 5-8°. There are three inequivalent O sites. In the first O site, O(1) is bonded to five equivalent Ba(1) and one Ti(1) atom to form a mixture of distorted corner and edge-sharing OBa5Ti octahedra. The corner-sharing octahedral tilt angles are 3°. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Ti(1) atoms. In the third O site, O(3) is bonded in a distorted linear geometry to four equivalent Ba(2) and two equivalent Ti(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba3Ti2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.110
_cell_length_b   11.107
_cell_length_c   4.070
_cell_angle_alpha   79.483
_cell_angle_beta   79.405
_cell_angle_gamma   21.112
_symmetry_Int_Tables_number   1
_cell_volume   177.759
_cell_formula_units_Z   1
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
  Ba  Ba0  1  0.562  0.072  0.928  1.0
  Ba  Ba1  1  0.743  0.257  0.743  1.0
  Ba  Ba2  1  0.928  0.438  0.562  1.0
  Ti  Ti3  1  0.135  0.676  0.324  1.0
  Ti  Ti4  1  0.324  0.865  0.135  1.0
  O  O5  1  0.069  0.560  0.440  1.0
  O  O6  1  0.158  0.654  0.858  1.0
  O  O7  1  0.858  0.331  0.158  1.0
  O  O8  1  0.346  0.842  0.669  1.0
  O  O9  1  0.669  0.142  0.346  1.0
  O  O10  1  0.255  0.745  0.255  1.0
  O  O11  1  0.440  0.931  0.069  1.0
[/CIF]
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