The structure described by La2Ti3O9 crystallizes in the triclinic P-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(4), one O(6), one O(7), one O(8), one O(9), two equivalent O(2), and two equivalent O(3) atoms. In the second La site, La(2) is bonded in a 9-coordinate geometry to one O(2), one O(3), one O(4), one O(6), one O(7), one O(8), one O(9), and two equivalent O(1) atoms. There are three inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(2), one O(3), one O(5), and two equivalent O(1) atoms to form distorted TiO5 trigonal bipyramids that share corners with two equivalent Ti(2)O6 octahedra and  an edgeedge with one Ti(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 44-58°. In the second Ti site, Ti(2) is bonded to one O(8), one O(9), two equivalent O(4), and two equivalent O(5) atoms to form TiO6 octahedra that share corners with two equivalent Ti(3)O4 tetrahedra, corners with two equivalent Ti(1)O5 trigonal bipyramids, and edges with two equivalent Ti(2)O6 octahedra. In the third Ti site, Ti(3) is bonded to one O(6), one O(7), one O(8), and one O(9) atom to form corner-sharing TiO4 tetrahedra. The corner-sharing octahedral tilt angles range from 61-63°. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent La(2) and two equivalent Ti(1) atoms. In the second O site, O(2) is bonded to one La(2), two equivalent La(1), and one Ti(1) atom to form distorted edge-sharing OLa3Ti tetrahedra. In the third O site, O(3) is bonded in a 4-coordinate geometry to one La(2), two equivalent La(1), and one Ti(1) atom. In the fourth O site, O(4) is bonded in a distorted L-shaped geometry to one La(1), one La(2), and two equivalent Ti(2) atoms. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ti(1) and two equivalent Ti(2) atoms. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one La(1), one La(2), and one Ti(3) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one La(1), one La(2), and one Ti(3) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one La(1), one La(2), one Ti(2), and one Ti(3) atom. In the ninth O site, O(9) is bonded in a distorted bent 120 degrees geometry to one La(1), one La(2), one Ti(2), and one Ti(3) atom. is represented by the CIF card [CIF]
data_La2Ti3O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.914
_cell_length_b   7.920
_cell_length_c   9.012
_cell_angle_alpha   108.399
_cell_angle_beta   108.236
_cell_angle_gamma   91.228
_symmetry_Int_Tables_number   1
_cell_volume   377.043
_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  0.807  0.181  0.580  1.0
  La  La1  1  0.129  0.193  0.215  1.0
  La  La2  1  0.871  0.807  0.785  1.0
  La  La3  1  0.193  0.819  0.420  1.0
  Ti  Ti4  1  0.426  0.076  0.851  1.0
  Ti  Ti5  1  0.767  0.486  0.998  1.0
  Ti  Ti6  1  0.339  0.484  0.661  1.0
  Ti  Ti7  1  0.661  0.516  0.339  1.0
  Ti  Ti8  1  0.233  0.514  0.002  1.0
  Ti  Ti9  1  0.574  0.924  0.149  1.0
  O  O10  1  0.716  0.003  0.998  1.0
  O  O11  1  0.118  0.011  0.694  1.0
  O  O12  1  0.579  0.025  0.690  1.0
  O  O13  1  0.990  0.325  0.955  1.0
  O  O14  1  0.460  0.325  0.949  1.0
  O  O15  1  0.184  0.281  0.497  1.0
  O  O16  1  0.612  0.321  0.390  1.0
  O  O17  1  0.657  0.461  0.763  1.0
  O  O18  1  0.121  0.521  0.775  1.0
  O  O19  1  0.879  0.479  0.225  1.0
  O  O20  1  0.343  0.539  0.237  1.0
  O  O21  1  0.388  0.679  0.610  1.0
  O  O22  1  0.816  0.719  0.503  1.0
  O  O23  1  0.540  0.675  0.051  1.0
  O  O24  1  0.010  0.675  0.045  1.0
  O  O25  1  0.421  0.975  0.310  1.0
  O  O26  1  0.882  0.989  0.306  1.0
  O  O27  1  0.284  0.997  0.002  1.0
[/CIF]
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The structure described by La2Ti3O9 crystallizes in the triclinic P-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(4), one O(6), one O(7), one O(8), one O(9), two equivalent O(2), and two equivalent O(3) atoms. In the second La site, La(2) is bonded in a 9-coordinate geometry to one O(2), one O(3), one O(4), one O(6), one O(7), one O(8), one O(9), and two equivalent O(1) atoms. There are three inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(2), one O(3), one O(5), and two equivalent O(1) atoms to form distorted TiO5 trigonal bipyramids that share corners with two equivalent Ti(2)O6 octahedra and  an edgeedge with one Ti(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 44-58°. In the second Ti site, Ti(2) is bonded to one O(8), one O(9), two equivalent O(4), and two equivalent O(5) atoms to form TiO6 octahedra that share corners with two equivalent Ti(3)O4 tetrahedra, corners with two equivalent Ti(1)O5 trigonal bipyramids, and edges with two equivalent Ti(2)O6 octahedra. In the third Ti site, Ti(3) is bonded to one O(6), one O(7), one O(8), and one O(9) atom to form corner-sharing TiO4 tetrahedra. The corner-sharing octahedral tilt angles range from 61-63°. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent La(2) and two equivalent Ti(1) atoms. In the second O site, O(2) is bonded to one La(2), two equivalent La(1), and one Ti(1) atom to form distorted edge-sharing OLa3Ti tetrahedra. In the third O site, O(3) is bonded in a 4-coordinate geometry to one La(2), two equivalent La(1), and one Ti(1) atom. In the fourth O site, O(4) is bonded in a distorted L-shaped geometry to one La(1), one La(2), and two equivalent Ti(2) atoms. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ti(1) and two equivalent Ti(2) atoms. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one La(1), one La(2), and one Ti(3) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one La(1), one La(2), and one Ti(3) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one La(1), one La(2), one Ti(2), and one Ti(3) atom. In the ninth O site, O(9) is bonded in a distorted bent 120 degrees geometry to one La(1), one La(2), one Ti(2), and one Ti(3) atom. is represented by the CIF card [CIF]
data_La2Ti3O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.914
_cell_length_b   7.920
_cell_length_c   9.012
_cell_angle_alpha   108.399
_cell_angle_beta   108.236
_cell_angle_gamma   91.228
_symmetry_Int_Tables_number   1
_cell_volume   377.043
_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  0.807  0.181  0.580  1.0
  La  La1  1  0.129  0.193  0.215  1.0
  La  La2  1  0.871  0.807  0.785  1.0
  La  La3  1  0.193  0.819  0.420  1.0
  Ti  Ti4  1  0.426  0.076  0.851  1.0
  Ti  Ti5  1  0.767  0.486  0.998  1.0
  Ti  Ti6  1  0.339  0.484  0.661  1.0
  Ti  Ti7  1  0.661  0.516  0.339  1.0
  Ti  Ti8  1  0.233  0.514  0.002  1.0
  Ti  Ti9  1  0.574  0.924  0.149  1.0
  O  O10  1  0.716  0.003  0.998  1.0
  O  O11  1  0.118  0.011  0.694  1.0
  O  O12  1  0.579  0.025  0.690  1.0
  O  O13  1  0.990  0.325  0.955  1.0
  O  O14  1  0.460  0.325  0.949  1.0
  O  O15  1  0.184  0.281  0.497  1.0
  O  O16  1  0.612  0.321  0.390  1.0
  O  O17  1  0.657  0.461  0.763  1.0
  O  O18  1  0.121  0.521  0.775  1.0
  O  O19  1  0.879  0.479  0.225  1.0
  O  O20  1  0.343  0.539  0.237  1.0
  O  O21  1  0.388  0.679  0.610  1.0
  O  O22  1  0.816  0.719  0.503  1.0
  O  O23  1  0.540  0.675  0.051  1.0
  O  O24  1  0.010  0.675  0.045  1.0
  O  O25  1  0.421  0.975  0.310  1.0
  O  O26  1  0.882  0.989  0.306  1.0
  O  O27  1  0.284  0.997  0.002  1.0
[/CIF]
.