The crystal structure described by Ca2La4Ti5O18 crystallizes in the trigonal R-3m space group. Ca(1) is bonded to three equivalent O(1) and nine equivalent O(2) atoms to form CaO12 cuboctahedra that share corners with three equivalent La(1)O12 cuboctahedra, corners with three equivalent La(2)O12 cuboctahedra, corners with six equivalent Ca(1)O12 cuboctahedra, faces with three equivalent Ca(1)O12 cuboctahedra, faces with three equivalent La(1)O12 cuboctahedra,  a faceface with one Ti(2)O6 octahedra, faces with three equivalent Ti(1)O6 octahedra, and faces with four equivalent Ti(3)O6 octahedra. There are two inequivalent La sites. In the first La site, La(1) is bonded to three equivalent O(2), three equivalent O(3), and six equivalent O(1) atoms to form LaO12 cuboctahedra that share corners with three equivalent Ca(1)O12 cuboctahedra, corners with six equivalent La(1)O12 cuboctahedra, faces with three equivalent Ca(1)O12 cuboctahedra, faces with four equivalent La(2)O12 cuboctahedra,  a faceface with one Ti(1)O6 octahedra, faces with three equivalent Ti(2)O6 octahedra, and faces with three equivalent Ti(3)O6 octahedra. In the second La site, La(2) is bonded to three equivalent O(1) and nine equivalent O(3) atoms to form distorted LaO12 cuboctahedra that share corners with three equivalent Ca(1)O12 cuboctahedra, corners with six equivalent La(2)O12 cuboctahedra, corners with three equivalent Ti(2)O6 octahedra, faces with three equivalent La(2)O12 cuboctahedra, faces with four equivalent La(1)O12 cuboctahedra,  a faceface with one Ti(3)O6 octahedra, and faces with three equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles are 25°. There are three inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to six equivalent O(2) atoms to form TiO6 octahedra that share corners with six equivalent Ti(3)O6 octahedra, faces with two equivalent La(1)O12 cuboctahedra, and faces with six equivalent Ca(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. In the second Ti site, Ti(2) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form TiO6 octahedra that share corners with three equivalent La(2)O12 cuboctahedra, corners with three equivalent Ti(3)O6 octahedra,  a faceface with one Ca(1)O12 cuboctahedra, faces with three equivalent La(1)O12 cuboctahedra, and faces with three equivalent La(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 6°. In the third Ti site, Ti(3) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form TiO6 octahedra that share corners with three equivalent Ti(1)O6 octahedra, corners with three equivalent Ti(2)O6 octahedra,  a faceface with one La(2)O12 cuboctahedra, faces with three equivalent La(1)O12 cuboctahedra, and faces with four equivalent Ca(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-6°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to one Ca(1), one La(2), two equivalent La(1), one Ti(2), and one Ti(3) atom. In the second O site, O(2) is bonded in a distorted linear geometry to three equivalent Ca(1), one La(1), one Ti(1), and one Ti(3) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one La(1), three equivalent La(2), and one Ti(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca2La4Ti5O18
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.535
_cell_length_b   5.535
_cell_length_c   13.712
_cell_angle_alpha   78.355
_cell_angle_beta   78.355
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   353.826
_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
  Ca  Ca0  1  0.361  0.361  0.917  1.0
  Ca  Ca1  1  0.639  0.639  0.083  1.0
  La  La2  1  0.087  0.087  0.739  1.0
  La  La3  1  0.913  0.913  0.261  1.0
  La  La4  1  0.187  0.187  0.438  1.0
  La  La5  1  0.813  0.813  0.562  1.0
  Ti  Ti6  1  0.000  0.000  0.000  1.0
  Ti  Ti7  1  0.450  0.450  0.651  1.0
  Ti  Ti8  1  0.550  0.550  0.349  1.0
  Ti  Ti9  1  0.277  0.277  0.169  1.0
  Ti  Ti10  1  0.723  0.723  0.831  1.0
  O  O11  1  0.916  0.417  0.250  1.0
  O  O12  1  0.417  0.417  0.250  1.0
  O  O13  1  0.417  0.916  0.250  1.0
  O  O14  1  0.084  0.583  0.750  1.0
  O  O15  1  0.583  0.583  0.750  1.0
  O  O16  1  0.583  0.084  0.750  1.0
  O  O17  1  0.360  0.862  0.916  1.0
  O  O18  1  0.862  0.862  0.916  1.0
  O  O19  1  0.862  0.360  0.916  1.0
  O  O20  1  0.640  0.138  0.084  1.0
  O  O21  1  0.138  0.138  0.084  1.0
  O  O22  1  0.138  0.640  0.084  1.0
  O  O23  1  0.818  0.298  0.587  1.0
  O  O24  1  0.298  0.298  0.587  1.0
  O  O25  1  0.298  0.818  0.587  1.0
  O  O26  1  0.182  0.702  0.413  1.0
  O  O27  1  0.702  0.702  0.413  1.0
  O  O28  1  0.702  0.182  0.413  1.0
[/CIF]
.
The crystal structure described by Ca2La4Ti5O18 crystallizes in the trigonal R-3m space group. Ca(1) is bonded to three equivalent O(1) and nine equivalent O(2) atoms to form CaO12 cuboctahedra that share corners with three equivalent La(1)O12 cuboctahedra, corners with three equivalent La(2)O12 cuboctahedra, corners with six equivalent Ca(1)O12 cuboctahedra, faces with three equivalent Ca(1)O12 cuboctahedra, faces with three equivalent La(1)O12 cuboctahedra,  a faceface with one Ti(2)O6 octahedra, faces with three equivalent Ti(1)O6 octahedra, and faces with four equivalent Ti(3)O6 octahedra. There are two inequivalent La sites. In the first La site, La(1) is bonded to three equivalent O(2), three equivalent O(3), and six equivalent O(1) atoms to form LaO12 cuboctahedra that share corners with three equivalent Ca(1)O12 cuboctahedra, corners with six equivalent La(1)O12 cuboctahedra, faces with three equivalent Ca(1)O12 cuboctahedra, faces with four equivalent La(2)O12 cuboctahedra,  a faceface with one Ti(1)O6 octahedra, faces with three equivalent Ti(2)O6 octahedra, and faces with three equivalent Ti(3)O6 octahedra. In the second La site, La(2) is bonded to three equivalent O(1) and nine equivalent O(3) atoms to form distorted LaO12 cuboctahedra that share corners with three equivalent Ca(1)O12 cuboctahedra, corners with six equivalent La(2)O12 cuboctahedra, corners with three equivalent Ti(2)O6 octahedra, faces with three equivalent La(2)O12 cuboctahedra, faces with four equivalent La(1)O12 cuboctahedra,  a faceface with one Ti(3)O6 octahedra, and faces with three equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles are 25°. There are three inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to six equivalent O(2) atoms to form TiO6 octahedra that share corners with six equivalent Ti(3)O6 octahedra, faces with two equivalent La(1)O12 cuboctahedra, and faces with six equivalent Ca(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. In the second Ti site, Ti(2) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form TiO6 octahedra that share corners with three equivalent La(2)O12 cuboctahedra, corners with three equivalent Ti(3)O6 octahedra,  a faceface with one Ca(1)O12 cuboctahedra, faces with three equivalent La(1)O12 cuboctahedra, and faces with three equivalent La(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 6°. In the third Ti site, Ti(3) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form TiO6 octahedra that share corners with three equivalent Ti(1)O6 octahedra, corners with three equivalent Ti(2)O6 octahedra,  a faceface with one La(2)O12 cuboctahedra, faces with three equivalent La(1)O12 cuboctahedra, and faces with four equivalent Ca(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-6°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to one Ca(1), one La(2), two equivalent La(1), one Ti(2), and one Ti(3) atom. In the second O site, O(2) is bonded in a distorted linear geometry to three equivalent Ca(1), one La(1), one Ti(1), and one Ti(3) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one La(1), three equivalent La(2), and one Ti(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca2La4Ti5O18
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.535
_cell_length_b   5.535
_cell_length_c   13.712
_cell_angle_alpha   78.355
_cell_angle_beta   78.355
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   353.826
_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
  Ca  Ca0  1  0.361  0.361  0.917  1.0
  Ca  Ca1  1  0.639  0.639  0.083  1.0
  La  La2  1  0.087  0.087  0.739  1.0
  La  La3  1  0.913  0.913  0.261  1.0
  La  La4  1  0.187  0.187  0.438  1.0
  La  La5  1  0.813  0.813  0.562  1.0
  Ti  Ti6  1  0.000  0.000  0.000  1.0
  Ti  Ti7  1  0.450  0.450  0.651  1.0
  Ti  Ti8  1  0.550  0.550  0.349  1.0
  Ti  Ti9  1  0.277  0.277  0.169  1.0
  Ti  Ti10  1  0.723  0.723  0.831  1.0
  O  O11  1  0.916  0.417  0.250  1.0
  O  O12  1  0.417  0.417  0.250  1.0
  O  O13  1  0.417  0.916  0.250  1.0
  O  O14  1  0.084  0.583  0.750  1.0
  O  O15  1  0.583  0.583  0.750  1.0
  O  O16  1  0.583  0.084  0.750  1.0
  O  O17  1  0.360  0.862  0.916  1.0
  O  O18  1  0.862  0.862  0.916  1.0
  O  O19  1  0.862  0.360  0.916  1.0
  O  O20  1  0.640  0.138  0.084  1.0
  O  O21  1  0.138  0.138  0.084  1.0
  O  O22  1  0.138  0.640  0.084  1.0
  O  O23  1  0.818  0.298  0.587  1.0
  O  O24  1  0.298  0.298  0.587  1.0
  O  O25  1  0.298  0.818  0.587  1.0
  O  O26  1  0.182  0.702  0.413  1.0
  O  O27  1  0.702  0.702  0.413  1.0
  O  O28  1  0.702  0.182  0.413  1.0
[/CIF]
.