The structure described by La2Ti3O9 crystallizes in the hexagonal P6_3/m space group. La(1) is bonded in a 6-coordinate geometry to six equivalent O(2) atoms. Ti(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form corner-sharing TiO4 tetrahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to two equivalent Ti(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent La(1) and one Ti(1) atom. is represented by the CIF card [CIF]
data_La2Ti3O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.010
_cell_length_b   7.010
_cell_length_c   10.697
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   455.252
_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  0.333  0.667  0.959  1.0
  La  La1  1  0.333  0.667  0.541  1.0
  La  La2  1  0.667  0.333  0.459  1.0
  La  La3  1  0.667  0.333  0.041  1.0
  Ti  Ti4  1  0.231  0.925  0.250  1.0
  Ti  Ti5  1  0.075  0.305  0.250  1.0
  Ti  Ti6  1  0.305  0.231  0.750  1.0
  Ti  Ti7  1  0.695  0.769  0.250  1.0
  Ti  Ti8  1  0.925  0.695  0.750  1.0
  Ti  Ti9  1  0.769  0.075  0.750  1.0
  O  O10  1  0.209  0.927  0.750  1.0
  O  O11  1  0.376  0.936  0.108  1.0
  O  O12  1  0.376  0.936  0.392  1.0
  O  O13  1  0.064  0.440  0.392  1.0
  O  O14  1  0.064  0.440  0.108  1.0
  O  O15  1  0.073  0.282  0.750  1.0
  O  O16  1  0.282  0.209  0.250  1.0
  O  O17  1  0.560  0.624  0.108  1.0
  O  O18  1  0.560  0.624  0.392  1.0
  O  O19  1  0.440  0.376  0.608  1.0
  O  O20  1  0.440  0.376  0.892  1.0
  O  O21  1  0.718  0.791  0.750  1.0
  O  O22  1  0.927  0.718  0.250  1.0
  O  O23  1  0.936  0.560  0.608  1.0
  O  O24  1  0.936  0.560  0.892  1.0
  O  O25  1  0.624  0.064  0.608  1.0
  O  O26  1  0.624  0.064  0.892  1.0
  O  O27  1  0.791  0.073  0.250  1.0
[/CIF]
.
The structure described by La2Ti3O9 crystallizes in the hexagonal P6_3/m space group. La(1) is bonded in a 6-coordinate geometry to six equivalent O(2) atoms. Ti(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form corner-sharing TiO4 tetrahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to two equivalent Ti(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent La(1) and one Ti(1) atom. is represented by the CIF card [CIF]
data_La2Ti3O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.010
_cell_length_b   7.010
_cell_length_c   10.697
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   455.252
_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  0.333  0.667  0.959  1.0
  La  La1  1  0.333  0.667  0.541  1.0
  La  La2  1  0.667  0.333  0.459  1.0
  La  La3  1  0.667  0.333  0.041  1.0
  Ti  Ti4  1  0.231  0.925  0.250  1.0
  Ti  Ti5  1  0.075  0.305  0.250  1.0
  Ti  Ti6  1  0.305  0.231  0.750  1.0
  Ti  Ti7  1  0.695  0.769  0.250  1.0
  Ti  Ti8  1  0.925  0.695  0.750  1.0
  Ti  Ti9  1  0.769  0.075  0.750  1.0
  O  O10  1  0.209  0.927  0.750  1.0
  O  O11  1  0.376  0.936  0.108  1.0
  O  O12  1  0.376  0.936  0.392  1.0
  O  O13  1  0.064  0.440  0.392  1.0
  O  O14  1  0.064  0.440  0.108  1.0
  O  O15  1  0.073  0.282  0.750  1.0
  O  O16  1  0.282  0.209  0.250  1.0
  O  O17  1  0.560  0.624  0.108  1.0
  O  O18  1  0.560  0.624  0.392  1.0
  O  O19  1  0.440  0.376  0.608  1.0
  O  O20  1  0.440  0.376  0.892  1.0
  O  O21  1  0.718  0.791  0.750  1.0
  O  O22  1  0.927  0.718  0.250  1.0
  O  O23  1  0.936  0.560  0.608  1.0
  O  O24  1  0.936  0.560  0.892  1.0
  O  O25  1  0.624  0.064  0.608  1.0
  O  O26  1  0.624  0.064  0.892  1.0
  O  O27  1  0.791  0.073  0.250  1.0
[/CIF]
.