The material structure described by La2Ti2O7 crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 9-coordinate geometry to one O(3), two equivalent O(2), three equivalent O(1), and three equivalent O(7) atoms. In the second La site, La(2) is bonded in a 12-coordinate geometry to one O(3), two equivalent O(2), two equivalent O(6), three equivalent O(4), and four equivalent O(5) atoms. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), one O(2), one O(6), one O(7), and two equivalent O(3) atoms to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 19-41°. In the second Ti site, Ti(2) is bonded to one O(2), one O(6), two equivalent O(4), and two equivalent O(5) atoms to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 14-41°. There are seven inequivalent O sites. In the first O site, O(1) is bonded to three equivalent La(1) and one Ti(1) atom to form distorted OLa3Ti tetrahedra that share  a cornercorner with one O(6)La2Ti2 tetrahedra and corners with six equivalent O(1)La3Ti tetrahedra. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent La(1), two equivalent La(2), one Ti(1), and one Ti(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one La(1), one La(2), and two equivalent Ti(1) atoms. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to three equivalent La(2) and two equivalent Ti(2) atoms. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to four equivalent La(2) and two equivalent Ti(2) atoms. In the sixth O site, O(6) is bonded to two equivalent La(2), one Ti(1), and one Ti(2) atom to form distorted OLa2Ti2 tetrahedra that share  a cornercorner with one O(1)La3Ti tetrahedra and corners with two equivalent O(6)La2Ti2 tetrahedra. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to three equivalent La(1) and one Ti(1) atom. is represented by the CIF card [CIF]
data_La2Ti2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.947
_cell_length_b   12.947
_cell_length_c   5.570
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   162.614
_symmetry_Int_Tables_number   1
_cell_volume   278.989
_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
  La  La0  1  0.298  0.702  0.662  1.0
  La  La1  1  0.702  0.298  0.162  1.0
  La  La2  1  0.447  0.553  0.245  1.0
  La  La3  1  0.553  0.447  0.745  1.0
  Ti  Ti4  1  0.837  0.163  0.204  1.0
  Ti  Ti5  1  0.163  0.837  0.704  1.0
  Ti  Ti6  1  0.940  0.060  0.741  1.0
  Ti  Ti7  1  0.060  0.940  0.241  1.0
  O  O8  1  0.780  0.220  0.418  1.0
  O  O9  1  0.220  0.780  0.918  1.0
  O  O10  1  0.883  0.117  0.551  1.0
  O  O11  1  0.117  0.883  0.051  1.0
  O  O12  1  0.347  0.653  0.243  1.0
  O  O13  1  0.653  0.347  0.743  1.0
  O  O14  1  0.451  0.549  0.769  1.0
  O  O15  1  0.549  0.451  0.269  1.0
  O  O16  1  0.989  0.011  0.476  1.0
  O  O17  1  0.011  0.989  0.976  1.0
  O  O18  1  0.092  0.908  0.560  1.0
  O  O19  1  0.908  0.092  0.060  1.0
  O  O20  1  0.202  0.798  0.436  1.0
  O  O21  1  0.798  0.202  0.936  1.0
[/CIF]
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The material structure described by La2Ti2O7 crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 9-coordinate geometry to one O(3), two equivalent O(2), three equivalent O(1), and three equivalent O(7) atoms. In the second La site, La(2) is bonded in a 12-coordinate geometry to one O(3), two equivalent O(2), two equivalent O(6), three equivalent O(4), and four equivalent O(5) atoms. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), one O(2), one O(6), one O(7), and two equivalent O(3) atoms to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 19-41°. In the second Ti site, Ti(2) is bonded to one O(2), one O(6), two equivalent O(4), and two equivalent O(5) atoms to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 14-41°. There are seven inequivalent O sites. In the first O site, O(1) is bonded to three equivalent La(1) and one Ti(1) atom to form distorted OLa3Ti tetrahedra that share  a cornercorner with one O(6)La2Ti2 tetrahedra and corners with six equivalent O(1)La3Ti tetrahedra. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent La(1), two equivalent La(2), one Ti(1), and one Ti(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one La(1), one La(2), and two equivalent Ti(1) atoms. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to three equivalent La(2) and two equivalent Ti(2) atoms. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to four equivalent La(2) and two equivalent Ti(2) atoms. In the sixth O site, O(6) is bonded to two equivalent La(2), one Ti(1), and one Ti(2) atom to form distorted OLa2Ti2 tetrahedra that share  a cornercorner with one O(1)La3Ti tetrahedra and corners with two equivalent O(6)La2Ti2 tetrahedra. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to three equivalent La(1) and one Ti(1) atom. is represented by the CIF card [CIF]
data_La2Ti2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.947
_cell_length_b   12.947
_cell_length_c   5.570
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   162.614
_symmetry_Int_Tables_number   1
_cell_volume   278.989
_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
  La  La0  1  0.298  0.702  0.662  1.0
  La  La1  1  0.702  0.298  0.162  1.0
  La  La2  1  0.447  0.553  0.245  1.0
  La  La3  1  0.553  0.447  0.745  1.0
  Ti  Ti4  1  0.837  0.163  0.204  1.0
  Ti  Ti5  1  0.163  0.837  0.704  1.0
  Ti  Ti6  1  0.940  0.060  0.741  1.0
  Ti  Ti7  1  0.060  0.940  0.241  1.0
  O  O8  1  0.780  0.220  0.418  1.0
  O  O9  1  0.220  0.780  0.918  1.0
  O  O10  1  0.883  0.117  0.551  1.0
  O  O11  1  0.117  0.883  0.051  1.0
  O  O12  1  0.347  0.653  0.243  1.0
  O  O13  1  0.653  0.347  0.743  1.0
  O  O14  1  0.451  0.549  0.769  1.0
  O  O15  1  0.549  0.451  0.269  1.0
  O  O16  1  0.989  0.011  0.476  1.0
  O  O17  1  0.011  0.989  0.976  1.0
  O  O18  1  0.092  0.908  0.560  1.0
  O  O19  1  0.908  0.092  0.060  1.0
  O  O20  1  0.202  0.798  0.436  1.0
  O  O21  1  0.798  0.202  0.936  1.0
[/CIF]
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