Perovskite-related LaTiO_3.41

Crystals of pentalanthanum pentatitanium heptadecaoxide (La₅Ti₅O₁₇ with 0.3% oxy­gen excess, or LaTiO_3.41) have been synthesized by floating-zone melting, and the structure has been solved using single-crystal X-ray diffraction intensities. The monoclinic (P2₁/c) structure consists of perovskite-like slabs of vertex-sharing TiO₆ octahedra, which are separated by additional oxy­gen layers. The slabs are five octahedra wide. Due to the adjustment of the TiO₆ octahedra to meet the coordination requirements of the La³⁺ cations, a superstructure develops along the a axis.

S1. Comment

A group of compounds with the chemical formula A_nB_nO_3n+2 (A is Sr, La or Ca, and B is Nb or Ti) have been studied recently because of their interesting electronic properties (Lichtenberg et al., 2001; Kuntscher, Schuppler et al., 2002; Kuntscher, van der Marel et al., 2002). The crystal structures of the members of this family consist of (110) slabs of the perovskite structure that are separated by layers of additional O atoms. The width of the slabs in terms of the number of octahedra corresponds to the value of n in the chemical formula. The ideal formula of the n = 5 member in the LaTiO_x system is La₅Ti₅O₁₇, or LaTiO_3.40, but this compound exists in the homogeneity range 3.40 < x < 3.42, as revealed by powder X-ray diffraction, high-resolution electron microscopy and thermogravimetry (Lichtenberg et al., 1991). The composition of the title compound, LaTiO_3.41 (0.3% oxygen excess), has been determined by thermogravimetric oxidation (Lichtenberg et al., 2001). It is not clear if this nonstoichiometry corresponds to cation deficiency or oxygen excess, but there are indications for the latter in related niobates with n = 4 (Lichtenberg et al., 2001).

The single-crystal used for the present X-ray diffraction data collection was broken off a larger piece of material synthesized by floating zone melting, with a composition of LaTiO_3.41 (Lichtenberg et al., 2001). Due to its layered structure, the material shows a perfect (001) cleavage, leading to the production of extremely thin plates when preparing single crystals. This property makes the correction for absorption effects indispensable and leads to an increased mosaic spread of crystals. In conjunction with the large cell dimension in the c direction, the mosaic spread limits the number of scans useful for obtaining integrated intensities. Depending on the scan direction in reciprocal space, some scans contained intensity from more than one reflection. These scans were recognized and discarded.

The chemical composition of the compound is slightly non-stoichiometric, but the presence of cation vacancies, or alternatively of excess oxygen, could not be analyzed with the data presented here. The anisotropic displacement parameters describe very oblate ellipsoids, which is due either to the absence of some reflections or to insufficient absorption correction. Hence, the physical meaning of the displacement parameters cannot be discussed. Their strong correlation with occupancy parameters also prohibits the refinement of the latter.

The refinement of the crystal structure shows that it consists of perovskite-type slabs five octahedra wide (Fig. 1). The topology proposed by Williams et al. (1991), based on electron microscopic observations, is confirmed, and the position estimates of Williams et al. (1991) are replaced by more precise values referring to the correct unit cell and symmetry. The unit-cell volume of LaTiO_3.41 is approximately twice as large as that of SrNbO_3.41 (Abrahams et al., 1998), while the symmetry is monoclinic for the former compared with orthorhombic for the latter. The differences between these two isotypic structures can be understood from the different chemical compositions. Divalent Sr is replaced by trivalent La, and nearly tetravalent Ti replaces approximately pentavalent Nb, thus transferring bond strength from the octahedral sites to the A sites. This substitution, in conjunction with differences in radii, distorts the oxygen environment of the metal atoms, causing local strain. This strain, in turn, is relieved by a commensurate modulation of the structure, leading to a twofold superstructure in the [100] direction of LaTiO_3.41 as compared with SrNbO_3.41. Indeed, the reflections with odd h indices have only 20% of the intensities of the reflections with even h indices. This is reflected by the atomic coordinates, whereby a counterpart near (x + 1/2, y, z) can be found for every atom site at (x, y, z).

The difference between orthorhombic SrNbO_3.41 and monoclinic LaTiO_3.41 can best be seen in the coordination of the A sites. Surprisingly, the major differences are not found for atoms near the additional oxygen layer, but for those in positions intermediate between the oxygen layer and the centre of the octahedral slab, i.e. atoms La2 and La3 (Fig. 1). While in SrNbO_3.41 the Sr atoms in this position are all symmetry equivalent and occupy the centre of the coordinating cuboctahedron (Fig. 2a), atoms La2 and La3 in LaTiO_3.41 are shifted away from the centres of their coordination polyhedra (Fig. 2 b). The shifts of the La2 and La3 positions are accompanied by rotations of the octahedra, in agreement with the lower symmetry of the La compound.

The distortions of the coordination polyhedra can be analyzed in terms of average metal-oxygen bond lengths and angles and their standard deviations (Table 1). The TiO₆ octahedra in the centre of the perovskite slabs are virtually undistorted with respect to bond lengths and angles. The distortion grows as the octahedra approach the rim of the slab, as shown by the increasing standard deviations of the mean Ti—O bond lengths (Table 1). No such significant difference can be found with respect to the average O—Ti—O angles. This agrees well with the situation found in SrNbO_3.41 (Abrahams et al., 1998), where the bond-length distortion of the corresponding NbO₆ octahedra is almost identical and the angular distortion grows only by a small amount when approaching the rim of the perovskite slab. While the La sites within the octahedral slabs (La1, La2, and La3) allow the description of their coordination by a distorted cuboctahedron, such a description is useless for La4 and La5. The latter are at the rim of the slabs, and consequently, two of the twelve O atoms of the cuboctahedron are missing. The actual positions of La4 and La5 are shifted away from the would be centre of the cuboctahedron into the direction of the opposite slab. The resulting irregular coordination is similar to that of Sr in Sr₂Nb₂O₇ (Daniels et al., 2002) and is tenfold for La4 and [seven + three]-fold for La5.

S2. Experimental

Please provide brief details of compound synthesis and crystal growth.

S3. Refinement

In the difference Fourier synthesis, the highest peak (3.22 e Å⁻¹) is at 0.8322, 0.5566, 0.1985 [0.56 Å from La5] and the deepest hole (−3.16 e Å⁻¹) is at 0.3587, 0.4674, 0.1929 [0.59 Å from La4].

Computing details

Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: HELENA (Spek, 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The crystal structure of LaTiO3.41 viewed along b. Large grey spheres represent La, smaller light-grey spheres are Ti, and the smallest and dark-grey spheres represent O atoms. The unit cell is outlined.
	Fig. 2. The coordination of (a) Sr3 in SrNbO3.41 viewed along a* and (b) La2 and La3 in LaTiO3.41 viewed along c*. The view directions relative to the topology are the same in both cases; only the unit-cell settings are different.

pentalanthanum pentatitanium heptadecaoxide

Crystal data

La5Ti5O17	F(000) = 2124
Mr = 1205.90	Dx = 5.906 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71069 Å
Hall symbol: -p 2ybc	Cell parameters from 25 reflections
a = 7.8580 (11) Å	θ = 18.0–22.7°
b = 5.5281 (9) Å	µ = 18.25 mm^−1
c = 31.449 (5) Å	T = 293 K
β = 97.166 (16)°	Irregular plate, dark-blue-black
V = 1355.5 (4) Å^3	0.10 × 0.08 × 0.01 mm
Z = 4

Data collection

Enraf-Nonius MACH3 diffractometer	5164 reflections with I > 2σ(I)
Radiation source: Nonius rotating anode generator	Rint = 0.053
Graphite monochromator	θmax = 36.9°, θmin = 1.3°
ω/2θ scans	h = −12→12
Absorption correction: ψ scan (Herrendorf, 1992)	k = −7→9
Tmin = 0.31, Tmax = 0.89	l = −53→50
21243 measured reflections	3 standard reflections every 60 min
6456 independent reflections	intensity decay: none

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.039	w = 1/[σ^2(Fo^2) + (0.0238P)^2 + 11.7499P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.082	(Δ/σ)max = 0.002
S = 1.13	Δρmax = 3.22 e Å^−3
6456 reflections	Δρmin = −3.16 e Å^−3
248 parameters	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.00024 (2)

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
La1	0.25173 (3)	0.00052 (5)	0.502664 (9)	0.00695 (6)
La2	0.29695 (3)	−0.00424 (5)	0.092757 (9)	0.00526 (6)
La3	0.79311 (3)	0.00169 (5)	0.087115 (9)	0.00665 (6)
La4	−0.35508 (4)	0.04768 (6)	0.294718 (10)	0.00941 (6)
La5	0.14382 (3)	0.08565 (5)	0.284710 (10)	0.00608 (6)
Ti1	0.5000	0.0000	0.0000	0.00393 (19)
Ti2	0.0000	0.0000	0.0000	0.00390 (19)
Ti3	0.54528 (10)	0.50568 (16)	0.09322 (3)	0.00388 (13)
Ti4	0.04726 (10)	0.50697 (16)	0.09266 (3)	0.00387 (13)
Ti5	0.08704 (11)	0.03592 (16)	0.17749 (3)	0.00440 (14)
Ti6	0.59026 (11)	0.03939 (16)	0.17870 (3)	0.00419 (14)
O1	0.5508 (5)	0.2810 (7)	0.03715 (12)	0.0084 (6)
O2	−0.0135 (5)	0.2795 (7)	0.03752 (12)	0.0081 (6)
O3	0.5060 (5)	0.7765 (7)	0.05044 (12)	0.0072 (6)
O4	0.0445 (5)	0.7748 (7)	0.04998 (13)	0.0090 (7)
O5	0.0914 (4)	0.2992 (7)	0.21231 (12)	0.0063 (6)
O6	0.6208 (5)	0.3106 (7)	0.20898 (14)	0.0100 (7)
O7	0.1230 (4)	0.8153 (7)	0.22172 (12)	0.0057 (6)
O8	0.6013 (4)	0.8224 (7)	0.22483 (12)	0.0057 (6)
O9	0.0476 (4)	0.1963 (7)	0.12086 (12)	0.0061 (6)
O10	0.5725 (4)	0.1943 (6)	0.12080 (12)	0.0053 (6)
O11	0.3366 (4)	0.0700 (8)	0.17234 (12)	0.0095 (7)
O12	0.8350 (4)	−0.0361 (7)	0.16952 (12)	0.0070 (6)
O13	0.1136 (5)	0.7135 (7)	0.13701 (12)	0.0085 (6)
O14	0.5240 (5)	0.7083 (7)	0.13823 (13)	0.0093 (7)
O15	0.7944 (5)	0.5414 (7)	0.08964 (13)	0.0097 (7)
O16	0.2904 (4)	0.4432 (7)	0.08152 (12)	0.0068 (6)
O17	0.7499 (4)	0.9488 (7)	−0.00103 (12)	0.0080 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
La1	0.00592 (11)	0.00706 (12)	0.00789 (12)	−0.00014 (9)	0.00090 (8)	−0.00118 (10)
La2	0.00332 (10)	0.00592 (12)	0.00659 (11)	−0.00016 (8)	0.00076 (8)	−0.00086 (9)
La3	0.00390 (11)	0.00764 (12)	0.00849 (12)	−0.00017 (9)	0.00110 (8)	−0.00144 (9)
La4	0.00330 (11)	0.00955 (13)	0.01566 (14)	−0.00069 (9)	0.00225 (9)	−0.00421 (10)
La5	0.00309 (10)	0.00519 (11)	0.01000 (12)	−0.00014 (9)	0.00094 (8)	−0.00143 (9)
Ti1	0.0026 (4)	0.0045 (5)	0.0046 (4)	−0.0007 (4)	0.0001 (3)	0.0002 (4)
Ti2	0.0028 (4)	0.0038 (5)	0.0049 (4)	−0.0007 (4)	0.0001 (3)	0.0003 (4)
Ti3	0.0038 (3)	0.0032 (3)	0.0047 (3)	0.0001 (3)	0.0005 (2)	0.0006 (3)
Ti4	0.0039 (3)	0.0032 (3)	0.0046 (3)	−0.0003 (3)	0.0005 (2)	0.0002 (3)
Ti5	0.0044 (3)	0.0035 (3)	0.0054 (3)	0.0005 (3)	0.0010 (2)	0.0004 (3)
Ti6	0.0047 (3)	0.0029 (3)	0.0049 (3)	−0.0005 (3)	0.0004 (2)	−0.0001 (3)
O1	0.0083 (15)	0.0084 (16)	0.0084 (16)	−0.0001 (12)	0.0009 (12)	−0.0003 (13)
O2	0.0107 (15)	0.0073 (16)	0.0063 (16)	0.0004 (12)	0.0005 (12)	−0.0026 (13)
O3	0.0092 (15)	0.0066 (15)	0.0059 (15)	0.0011 (12)	0.0011 (11)	0.0006 (13)
O4	0.0089 (15)	0.0101 (17)	0.0080 (16)	0.0001 (13)	0.0006 (12)	0.0026 (14)
O5	0.0060 (14)	0.0036 (15)	0.0096 (17)	0.0005 (11)	0.0018 (11)	−0.0018 (12)
O6	0.0032 (14)	0.0083 (17)	0.018 (2)	−0.0021 (12)	−0.0001 (12)	−0.0042 (15)
O7	0.0048 (14)	0.0059 (15)	0.0064 (16)	−0.0008 (11)	0.0001 (11)	−0.0036 (12)
O8	0.0047 (14)	0.0061 (15)	0.0065 (16)	0.0005 (11)	0.0018 (11)	0.0009 (12)
O9	0.0050 (14)	0.0064 (15)	0.0071 (16)	−0.0018 (11)	0.0012 (11)	0.0023 (12)
O10	0.0071 (14)	0.0010 (13)	0.0078 (16)	0.0008 (11)	0.0011 (11)	0.0002 (12)
O11	0.0010 (13)	0.0179 (19)	0.0093 (16)	−0.0015 (13)	−0.0005 (11)	−0.0003 (14)
O12	0.0019 (13)	0.0107 (16)	0.0086 (15)	0.0010 (12)	0.0012 (10)	0.0014 (13)
O13	0.0122 (16)	0.0064 (15)	0.0067 (16)	−0.0009 (13)	0.0005 (12)	−0.0021 (13)
O14	0.0105 (16)	0.0086 (16)	0.0088 (17)	0.0031 (13)	0.0008 (12)	−0.0003 (13)
O15	0.0054 (14)	0.0099 (17)	0.0136 (17)	−0.0013 (12)	0.0004 (12)	0.0001 (14)
O16	0.0038 (13)	0.0079 (16)	0.0089 (15)	−0.0008 (11)	0.0015 (11)	−0.0001 (13)
O17	0.0026 (13)	0.0094 (16)	0.0119 (17)	−0.0002 (12)	0.0000 (12)	−0.0010 (14)

Geometric parameters (Å, º)

La1—O1^i	2.435 (4)	Ti3—O1	2.162 (4)
La1—O2^ii	2.450 (4)	Ti3—La2^xviii	3.3378 (10)
La1—O17^i	2.479 (4)	Ti3—La3^xviii	3.3825 (10)
La1—O16^iii	2.480 (4)	Ti3—La1^xiv	3.4343 (11)
La1—O1^iii	2.743 (4)	Ti3—La1^v	3.5832 (10)
La1—O2^iii	2.756 (4)	Ti4—O13	1.827 (4)
La1—O4^iii	2.791 (4)	Ti4—O9	1.932 (4)
La1—O3^iii	2.801 (4)	Ti4—O15^xii	1.987 (4)
La1—O15^i	2.889 (4)	Ti4—O4	1.997 (4)
La1—O17^iv	3.050 (4)	Ti4—O16	2.016 (4)
La1—O4^ii	3.081 (4)	Ti4—O2	2.147 (4)
La1—O3^i	3.088 (4)	Ti4—La2^xviii	3.3391 (10)
La1—Ti1^v	3.3879 (5)	Ti4—La3^xix	3.3781 (10)
La1—Ti2^vi	3.3915 (5)	Ti4—La1^xiv	3.4248 (10)
La1—Ti1^i	3.3926 (5)	Ti4—La3^xii	3.4256 (10)
La2—O10	2.489 (4)	Ti4—La1^vi	3.5709 (11)
La2—O16	2.498 (4)	Ti5—O5	1.819 (4)
La2—O9	2.506 (4)	Ti5—O7^vii	1.845 (4)
La2—O11	2.517 (4)	Ti5—O9	1.979 (4)
La2—O3^vii	2.547 (4)	Ti5—O11	1.996 (4)
La2—O4^vii	2.564 (4)	Ti5—O12^xii	2.005 (4)
La2—O13^vii	2.636 (4)	Ti5—O13^vii	2.215 (4)
La2—O14^vii	2.668 (4)	Ti5—La5^ii	3.3820 (10)
La2—O17^viii	2.879 (4)	Ti5—La3^xii	3.4366 (11)
La2—O16^vii	3.075 (4)	Ti5—La4^ii	3.4678 (10)
La2—O2	3.221 (4)	Ti5—La4^vi	3.5700 (10)
La2—O1	3.224 (4)	Ti6—O6	1.776 (4)
La2—Ti5	3.3117 (10)	Ti6—O8^vii	1.876 (4)
La2—Ti6	3.3350 (11)	Ti6—O11	1.986 (4)
La2—Ti3^vii	3.3378 (10)	Ti6—O10	2.001 (4)
La3—O10	2.391 (3)	Ti6—O12	2.024 (3)
La3—O9^ix	2.399 (4)	Ti6—O14^vii	2.253 (4)
La3—O15^vii	2.546 (4)	Ti6—La5^i	3.3737 (10)
La3—O12	2.580 (4)	Ti6—La4^ii	3.4479 (10)
La3—O3^vii	2.705 (4)	Ti6—La4^vi	3.5206 (10)
La3—O4^x	2.723 (4)	Ti6—La4^ix	3.6204 (11)
La3—O17^vii	2.766 (4)	O1—La1^v	2.435 (4)
La3—O2^ix	2.773 (4)	O1—La1^xiv	2.743 (4)
La3—O1	2.781 (4)	O2—La1^vi	2.450 (4)
La3—O15	2.985 (4)	O2—La1^xiv	2.756 (4)
La3—O13^x	3.218 (4)	O2—La3^xii	2.773 (4)
La3—O14^vii	3.246 (4)	O3—Ti1^xviii	2.007 (4)
La3—Ti1	3.3521 (7)	O3—La2^xviii	2.547 (4)
La3—Ti2^ix	3.3557 (6)	O3—La3^xviii	2.705 (4)
La3—Ti4^x	3.3781 (10)	O3—La1^xiv	2.801 (4)
La4—O7^ii	2.453 (4)	O3—La1^v	3.088 (4)
La4—O6^ii	2.456 (4)	O4—Ti2^xviii	2.001 (4)
La4—O8^ii	2.476 (4)	O4—La2^xviii	2.564 (4)
La4—O8^xi	2.512 (4)	O4—La3^xix	2.723 (4)
La4—O5^ii	2.519 (4)	O4—La1^xiv	2.791 (4)
La4—O14^ii	2.774 (4)	O4—La1^vi	3.081 (4)
La4—O11^ii	2.834 (4)	O5—La5^vi	2.445 (4)
La4—O13^ii	2.834 (4)	O5—La4^vi	2.519 (4)
La4—O6^xii	3.048 (4)	O5—La5^ii	4.362 (4)
La4—O11^vi	3.065 (4)	O6—La5^v	2.384 (4)
La4—Ti6^vi	3.4479 (10)	O6—La4^vi	2.456 (4)
La4—Ti5^vi	3.4678 (10)	O6—La4^ix	3.048 (4)
La4—Ti6^ii	3.5206 (10)	O6—La5^i	4.408 (4)
La4—Ti5^ii	3.5700 (10)	O7—Ti5^xviii	1.845 (4)
La4—Ti6^xii	3.6204 (11)	O7—La5^vi	2.438 (4)
La5—O6^i	2.384 (4)	O7—La4^vi	2.453 (4)
La5—O7^ii	2.438 (4)	O7—La5^xviii	2.471 (4)
La5—O8^i	2.442 (3)	O8—Ti6^xviii	1.876 (4)
La5—O5^ii	2.445 (4)	O8—La5^v	2.442 (3)
La5—O7^vii	2.471 (4)	O8—La4^vi	2.476 (4)
La5—O12^v	2.532 (4)	O8—La4^xx	2.512 (4)
La5—O5	2.552 (4)	O9—La3^xii	2.399 (4)
La5—Ti5	3.3572 (10)	O9—La4^vi	3.880 (4)
La5—Ti6^v	3.3737 (10)	O9—La5^vi	4.102 (4)
La5—Ti5^vi	3.3820 (10)	O10—La4^vi	3.864 (4)
La5—O14^i	3.401 (4)	O10—La5^v	4.102 (4)
La5—O13^ii	3.449 (4)	O11—La4^vi	2.834 (4)
La5—O12^i	3.722 (4)	O11—La4^ii	3.065 (4)
La5—Ti6^i	3.7696 (10)	O11—La4^ix	4.286 (4)
La5—Ti5^ii	3.8050 (10)	O12—Ti5^ix	2.005 (3)
Ti1—O1^xiii	1.955 (4)	O12—La5^i	2.532 (4)
Ti1—O1	1.955 (4)	O12—La5^v	3.722 (4)
Ti1—O17^viii	1.989 (3)	O12—La5^ix	4.156 (4)
Ti1—O17^vii	1.989 (3)	O12—La4^ix	4.407 (4)
Ti1—O3^vii	2.007 (4)	O13—Ti5^xviii	2.215 (4)
Ti1—O3^viii	2.007 (4)	O13—La2^xviii	2.636 (4)
Ti1—La3^xiii	3.3521 (7)	O13—La4^vi	2.834 (4)
Ti1—La1^i	3.3879 (5)	O13—La3^xix	3.218 (4)
Ti1—La1^xiv	3.3879 (5)	O13—La5^vi	3.449 (4)
Ti1—La1^v	3.3926 (5)	O14—Ti6^xviii	2.253 (4)
Ti1—La1^xv	3.3926 (5)	O14—La2^xviii	2.668 (4)
Ti2—O2	1.955 (4)	O14—La4^vi	2.774 (4)
Ti2—O2^xvi	1.955 (4)	O14—La3^xviii	3.246 (4)
Ti2—O17^xi	1.982 (3)	O14—La5^v	3.401 (4)
Ti2—O17^viii	1.982 (3)	O15—Ti4^ix	1.987 (4)
Ti2—O4^vii	2.001 (4)	O15—La3^xviii	2.546 (4)
Ti2—O4^xvii	2.001 (4)	O15—La1^v	2.889 (4)
Ti2—La3^xii	3.3557 (6)	O15—La5^v	3.928 (4)
Ti2—La3^xiii	3.3557 (6)	O16—La1^xiv	2.480 (4)
Ti2—La1^xiv	3.3915 (5)	O16—La2^xviii	3.075 (4)
Ti2—La1^ii	3.3915 (5)	O16—La4^vi	3.905 (4)
Ti2—La1^xv	3.3962 (5)	O17—Ti2^xx	1.982 (3)
Ti2—La1^vi	3.3962 (5)	O17—Ti1^xviii	1.989 (3)
Ti3—O14	1.829 (4)	O17—La1^v	2.479 (4)
Ti3—O10	1.927 (4)	O17—La3^xviii	2.766 (4)
Ti3—O15	1.984 (4)	O17—La2^viii	2.879 (4)
Ti3—O3	2.011 (4)	O17—La1^xxi	3.050 (4)
Ti3—O16	2.021 (4)
O1^i—La1—O2^ii	88.92 (13)	O17^viii—Ti2—O4^vii	90.03 (15)
O1^i—La1—O17^i	119.30 (12)	O2—Ti2—O4^xvii	88.00 (17)
O2^ii—La1—O17^i	119.09 (12)	O2^xvi—Ti2—O4^xvii	92.00 (17)
O1^i—La1—O16^iii	124.76 (12)	O17^xi—Ti2—O4^xvii	90.03 (15)
O2^ii—La1—O16^iii	124.66 (12)	O17^viii—Ti2—O4^xvii	89.97 (15)
O17^i—La1—O16^iii	83.98 (12)	O4^vii—Ti2—O4^xvii	180.00 (15)
O1^i—La1—O1^iii	81.56 (14)	O14—Ti3—O10	102.39 (17)
O2^ii—La1—O1^iii	170.17 (12)	O14—Ti3—O15	99.73 (17)
O17^i—La1—O1^iii	64.54 (12)	O10—Ti3—O15	93.40 (16)
O16^iii—La1—O1^iii	63.73 (12)	O14—Ti3—O3	92.33 (17)
O1^i—La1—O2^iii	170.48 (12)	O10—Ti3—O3	164.85 (16)
O2^ii—La1—O2^iii	81.85 (13)	O15—Ti3—O3	87.59 (16)
O17^i—La1—O2^iii	64.20 (11)	O14—Ti3—O16	93.53 (16)
O16^iii—La1—O2^iii	63.34 (12)	O10—Ti3—O16	88.93 (15)
O1^iii—La1—O2^iii	107.56 (12)	O15—Ti3—O16	165.70 (17)
O1^i—La1—O4^iii	117.00 (13)	O3—Ti3—O16	86.53 (15)
O2^ii—La1—O4^iii	62.86 (12)	O14—Ti3—O1	175.03 (17)
O17^i—La1—O4^iii	123.67 (12)	O10—Ti3—O1	80.89 (15)
O16^iii—La1—O4^iii	62.75 (12)	O15—Ti3—O1	83.71 (16)
O1^iii—La1—O4^iii	123.89 (12)	O3—Ti3—O1	84.20 (16)
O2^iii—La1—O4^iii	60.52 (11)	O16—Ti3—O1	82.74 (15)
O1^i—La1—O3^iii	62.99 (12)	O13—Ti4—O9	102.77 (17)
O2^ii—La1—O3^iii	116.87 (12)	O13—Ti4—O15^xii	99.51 (17)
O17^i—La1—O3^iii	124.01 (11)	O9—Ti4—O15^xii	92.94 (16)
O16^iii—La1—O3^iii	62.74 (11)	O13—Ti4—O4	91.61 (17)
O1^iii—La1—O3^iii	60.65 (11)	O9—Ti4—O4	165.15 (17)
O2^iii—La1—O3^iii	123.52 (11)	O15^xii—Ti4—O4	88.27 (16)
O4^iii—La1—O3^iii	80.83 (11)	O13—Ti4—O16	93.18 (16)
O1^i—La1—O15^i	61.99 (12)	O9—Ti4—O16	88.69 (15)
O2^ii—La1—O15^i	61.89 (12)	O15^xii—Ti4—O16	166.50 (17)
O17^i—La1—O15^i	84.33 (12)	O4—Ti4—O16	86.79 (16)
O16^iii—La1—O15^i	168.31 (12)	O13—Ti4—O2	174.82 (16)
O1^iii—La1—O15^i	110.90 (11)	O9—Ti4—O2	80.65 (16)
O2^iii—La1—O15^i	111.04 (11)	O15^xii—Ti4—O2	84.09 (16)
O4^iii—La1—O15^i	124.75 (11)	O4—Ti4—O2	84.75 (16)
O3^iii—La1—O15^i	124.98 (11)	O16—Ti4—O2	82.95 (15)
O10—La2—O16	67.37 (12)	O5—Ti5—O7^vii	94.89 (17)
O10—La2—O9	111.33 (12)	O5—Ti5—O9	99.93 (17)
O16—La2—O9	66.96 (11)	O7^vii—Ti5—O9	165.18 (17)
O10—La2—O11	65.26 (12)	O5—Ti5—O11	91.63 (16)
O16—La2—O11	88.68 (13)	O7^vii—Ti5—O11	93.66 (16)
O9—La2—O11	65.31 (12)	O9—Ti5—O11	85.96 (15)
O10—La2—O3^vii	78.78 (12)	O5—Ti5—O12^xii	100.27 (16)
O16—La2—O3^vii	113.61 (12)	O7^vii—Ti5—O12^xii	91.09 (16)
O9—La2—O3^vii	168.12 (12)	O9—Ti5—O12^xii	86.29 (15)
O11—La2—O3^vii	126.12 (12)	O11—Ti5—O12^xii	166.77 (17)
O10—La2—O4^vii	168.01 (12)	O5—Ti5—O13^vii	173.51 (15)
O16—La2—O4^vii	113.36 (12)	O7^vii—Ti5—O13^vii	83.39 (16)
O9—La2—O4^vii	78.93 (12)	O9—Ti5—O13^vii	81.88 (15)
O11—La2—O4^vii	126.24 (12)	O11—Ti5—O13^vii	82.26 (16)
O3^vii—La2—O4^vii	90.37 (12)	O12^xii—Ti5—O13^vii	86.03 (15)
O10—La2—O13^vii	125.63 (12)	O6—Ti6—O8^vii	97.77 (19)
O16—La2—O13^vii	131.14 (12)	O6—Ti6—O11	92.80 (17)
O9—La2—O13^vii	64.72 (12)	O8^vii—Ti6—O11	94.68 (16)
O11—La2—O13^vii	65.13 (12)	O6—Ti6—O10	96.66 (18)
O3^vii—La2—O13^vii	115.15 (12)	O8^vii—Ti6—O10	165.56 (16)
O4^vii—La2—O13^vii	63.70 (12)	O11—Ti6—O10	85.22 (15)
O10—La2—O14^vii	65.08 (12)	O6—Ti6—O12	100.57 (16)
O16—La2—O14^vii	131.78 (12)	O8^vii—Ti6—O12	91.45 (15)
O9—La2—O14^vii	125.07 (12)	O11—Ti6—O12	164.41 (17)
O11—La2—O14^vii	64.70 (12)	O10—Ti6—O12	85.29 (15)
O3^vii—La2—O14^vii	64.19 (12)	O6—Ti6—O14^vii	174.17 (16)
O4^vii—La2—O14^vii	114.80 (12)	O8^vii—Ti6—O14^vii	84.40 (16)
O13^vii—La2—O14^vii	74.77 (12)	O11—Ti6—O14^vii	81.61 (16)
O10—La2—O17^viii	107.76 (11)	O10—Ti6—O14^vii	81.29 (15)
O16—La2—O17^viii	75.82 (12)	O12—Ti6—O14^vii	84.75 (15)
O9—La2—O17^viii	107.36 (11)	Ti1—O1—Ti3	157.0 (2)
O11—La2—O17^viii	164.50 (13)	Ti1—O1—La1^v	100.63 (16)
O3^vii—La2—O17^viii	62.43 (11)	Ti3—O1—La1^v	102.25 (15)
O4^vii—La2—O17^viii	62.02 (11)	Ti1—O1—La1^xiv	90.71 (14)
O13^vii—La2—O17^viii	125.60 (11)	Ti3—O1—La1^xiv	88.06 (13)
O14^vii—La2—O17^viii	126.44 (11)	La1^v—O1—La1^xiv	98.44 (13)
O10—La3—O9^ix	102.40 (12)	Ti1—O1—La3	88.33 (14)
O10—La3—O15^vii	115.56 (12)	Ti3—O1—La3	86.56 (13)
O9^ix—La3—O15^vii	115.77 (12)	La1^v—O1—La3	97.59 (12)
O10—La3—O12	66.41 (12)	La1^xiv—O1—La3	163.84 (16)
O9^ix—La3—O12	66.24 (12)	Ti2—O2—Ti4	158.0 (2)
O15^vii—La3—O12	83.57 (13)	Ti2—O2—La1^vi	100.27 (16)
O10—La3—O3^vii	77.40 (12)	Ti4—O2—La1^vi	101.72 (15)
O9^ix—La3—O3^vii	178.87 (12)	Ti2—O2—La1^xiv	90.46 (13)
O15^vii—La3—O3^vii	63.46 (12)	Ti4—O2—La1^xiv	87.69 (13)
O12—La3—O3^vii	112.72 (11)	La1^vi—O2—La1^xiv	98.15 (13)
O10—La3—O4^x	178.81 (12)	Ti2—O2—La3^xii	88.66 (14)
O9^ix—La3—O4^x	77.70 (12)	Ti4—O2—La3^xii	87.27 (13)
O15^vii—La3—O4^x	63.43 (12)	La1^vi—O2—La3^xii	97.43 (12)
O12—La3—O4^x	112.64 (11)	La1^xiv—O2—La3^xii	164.30 (16)
O3^vii—La3—O4^x	102.48 (12)	Ti1^xviii—O3—Ti3	166.9 (2)
O10—La3—O17^vii	119.08 (11)	Ti1^xviii—O3—La2^xviii	99.61 (15)
O9^ix—La3—O17^vii	118.82 (11)	Ti3—O3—La2^xviii	93.43 (14)
O15^vii—La3—O17^vii	85.71 (12)	Ti1^xviii—O3—La3^xviii	89.43 (13)
O12—La3—O17^vii	169.28 (12)	Ti3—O3—La3^xviii	90.41 (14)
O3^vii—La3—O17^vii	62.13 (11)	La2^xviii—O3—La3^xviii	96.68 (13)
O4^x—La3—O17^vii	61.72 (11)	Ti1^xviii—O3—La1^xiv	88.14 (13)
O10—La3—O2^ix	118.74 (12)	Ti3—O3—La1^xiv	89.51 (13)
O9^ix—La3—O2^ix	61.01 (12)	La2^xviii—O3—La1^xiv	94.41 (11)
O15^vii—La3—O2^ix	124.80 (12)	La3^xviii—O3—La1^xiv	168.90 (15)
O12—La3—O2^ix	126.84 (11)	Ti4—O4—Ti2^xviii	167.3 (2)
O3^vii—La3—O2^ix	120.08 (11)	Ti4—O4—La2^xviii	93.30 (15)
O4^x—La3—O2^ix	62.37 (11)	Ti2^xviii—O4—La2^xviii	99.41 (15)
O17^vii—La3—O2^ix	60.14 (11)	Ti4—O4—La3^xix	90.05 (14)
O10—La3—O1	61.32 (12)	Ti2^xviii—O4—La3^xix	89.16 (14)
O9^ix—La3—O1	118.37 (12)	La2^xviii—O4—La3^xix	96.35 (13)
O15^vii—La3—O1	124.92 (12)	Ti4—O4—La1^xiv	89.77 (14)
O12—La3—O1	127.25 (11)	Ti2^xviii—O4—La1^xiv	88.67 (14)
O3^vii—La3—O1	62.54 (11)	La2^xviii—O4—La1^xiv	94.28 (12)
O4^x—La3—O1	119.71 (11)	La3^xix—O4—La1^xiv	169.35 (16)
O17^vii—La3—O1	60.17 (11)	Ti5—O5—La5^vi	125.72 (18)
O2^ix—La3—O1	76.07 (11)	Ti5—O5—La4^vi	109.71 (16)
O10—La3—O15	62.82 (11)	La5^vi—O5—La4^vi	106.52 (14)
O9^ix—La3—O15	62.61 (11)	Ti5—O5—La5	98.97 (16)
O15^vii—La3—O15	176.71 (17)	La5^vi—O5—La5	107.71 (13)
O12—La3—O15	93.14 (12)	La4^vi—O5—La5	106.71 (14)
O3^vii—La3—O15	118.10 (11)	Ti6—O6—La5^v	129.39 (19)
O4^x—La3—O15	118.15 (11)	Ti6—O6—La4^vi	111.59 (17)
O17^vii—La3—O15	97.58 (11)	La5^v—O6—La4^vi	108.05 (16)
O2^ix—La3—O15	57.40 (11)	Ti5^xviii—O7—La5^vi	103.43 (15)
O1—La3—O15	57.29 (11)	Ti5^xviii—O7—La4^vi	106.73 (16)
O7^ii—La4—O6^ii	164.16 (13)	La5^vi—O7—La4^vi	108.84 (14)
O7^ii—La4—O8^ii	98.99 (12)	Ti5^xviii—O7—La5^xviii	101.14 (16)
O6^ii—La4—O8^ii	71.46 (13)	La5^vi—O7—La5^xviii	110.59 (13)
O7^ii—La4—O8^xi	97.95 (12)	La4^vi—O7—La5^xviii	123.88 (14)
O6^ii—La4—O8^xi	70.83 (13)	Ti6^xviii—O8—La5^v	101.96 (14)
O8^ii—La4—O8^xi	94.00 (7)	Ti6^xviii—O8—La4^vi	103.93 (15)
O7^ii—La4—O5^ii	70.67 (12)	La5^v—O8—La4^vi	105.56 (14)
O6^ii—La4—O5^ii	114.12 (13)	Ti6^xviii—O8—La4^xx	110.34 (17)
O8^ii—La4—O5^ii	159.82 (12)	La5^v—O8—La4^xx	110.41 (13)
O8^xi—La4—O5^ii	71.14 (12)	La4^vi—O8—La4^xx	122.57 (14)
O7^ii—La4—O14^ii	113.96 (12)	Ti4—O9—Ti5	143.3 (2)
O6^ii—La4—O14^ii	73.87 (13)	Ti4—O9—La3^xii	104.01 (16)
O8^ii—La4—O14^ii	63.85 (12)	Ti5—O9—La3^xii	103.01 (15)
O8^xi—La4—O14^ii	142.91 (11)	Ti4—O9—La2	100.83 (14)
O5^ii—La4—O14^ii	135.91 (12)	Ti5—O9—La2	94.45 (14)
O7^ii—La4—O11^ii	129.31 (11)	La3^xii—O9—La2	106.91 (14)
O6^ii—La4—O11^ii	61.61 (12)	Ti3—O10—Ti6	141.5 (2)
O8^ii—La4—O11^ii	131.69 (11)	Ti3—O10—La3	104.15 (15)
O8^xi—La4—O11^ii	81.55 (12)	Ti6—O10—La3	103.92 (15)
O5^ii—La4—O11^ii	61.22 (11)	Ti3—O10—La2	101.04 (15)
O14^ii—La4—O11^ii	91.60 (11)	Ti6—O10—La2	95.30 (14)
O7^ii—La4—O13^ii	61.29 (12)	La3—O10—La2	107.06 (14)
O6^ii—La4—O13^ii	133.89 (13)	Ti6—O11—Ti5	165.4 (2)
O8^ii—La4—O13^ii	114.72 (12)	Ti6—O11—La2	94.84 (14)
O8^xi—La4—O13^ii	145.94 (11)	Ti5—O11—La2	93.69 (14)
O5^ii—La4—O13^ii	76.27 (12)	Ti6—O11—La4^vi	92.15 (14)
O14^ii—La4—O13^ii	70.08 (11)	Ti5—O11—La4^vi	93.70 (15)
O11^ii—La4—O13^ii	91.46 (11)	La2—O11—La4^vi	120.66 (16)
O6^i—La5—O7^ii	171.72 (13)	Ti5^ix—O12—Ti6	152.0 (2)
O6^i—La5—O8^i	73.28 (13)	Ti5^ix—O12—La5^i	95.70 (14)
O7^ii—La5—O8^i	114.89 (13)	Ti6—O12—La5^i	94.89 (14)
O6^i—La5—O5^ii	99.56 (13)	Ti5^ix—O12—La3	96.31 (14)
O7^ii—La5—O5^ii	72.17 (12)	Ti6—O12—La3	97.02 (14)
O8^i—La5—O5^ii	170.91 (13)	La5^i—O12—La3	128.99 (16)
O6^i—La5—O7^vii	69.75 (14)	Ti4—O13—Ti5^xviii	154.5 (2)
O7^ii—La5—O7^vii	106.16 (7)	Ti4—O13—La2^xviii	95.14 (15)
O8^i—La5—O7^vii	101.47 (12)	Ti5^xviii—O13—La2^xviii	85.65 (13)
O5^ii—La5—O7^vii	70.37 (12)	Ti4—O13—La4^vi	118.45 (18)
O6^i—La5—O12^v	118.96 (13)	Ti5^xviii—O13—La4^vi	85.82 (12)
O7^ii—La5—O12^v	67.17 (12)	La2^xviii—O13—La4^vi	103.49 (12)
O8^i—La5—O12^v	68.33 (12)	Ti3—O14—Ti6^xviii	153.9 (2)
O5^ii—La5—O12^v	120.63 (12)	Ti3—O14—La2^xviii	93.99 (16)
O7^vii—La5—O12^v	161.52 (12)	Ti6^xviii—O14—La2^xviii	84.88 (13)
O6^i—La5—O5	113.99 (13)	Ti3—O14—La4^vi	119.40 (18)
O7^ii—La5—O5	69.12 (11)	Ti6^xviii—O14—La4^vi	85.94 (12)
O8^i—La5—O5	71.71 (12)	La2^xviii—O14—La4^vi	104.28 (12)
O5^ii—La5—O5	107.16 (8)	Ti3—O15—Ti4^ix	167.3 (2)
O7^vii—La5—O5	65.00 (12)	Ti3—O15—La3^xviii	95.81 (15)
O12^v—La5—O5	96.73 (12)	Ti4^ix—O15—La3^xviii	95.57 (15)
O1^xiii—Ti1—O1	180.00 (19)	Ti3—O15—La1^v	92.77 (14)
O1^xiii—Ti1—O17^viii	89.67 (15)	Ti4^ix—O15—La1^v	92.28 (14)
O1—Ti1—O17^viii	90.33 (15)	La3^xviii—O15—La1^v	92.71 (13)
O1^xiii—Ti1—O17^vii	90.33 (15)	Ti3—O15—La3	84.38 (13)
O1—Ti1—O17^vii	89.67 (15)	Ti4^ix—O15—La3	84.58 (14)
O17^viii—Ti1—O17^vii	180.0	La3^xviii—O15—La3	176.71 (17)
O1^xiii—Ti1—O3^vii	88.06 (16)	La1^v—O15—La3	84.00 (11)
O1—Ti1—O3^vii	91.94 (16)	Ti4—O16—Ti3	151.4 (2)
O17^viii—Ti1—O3^vii	90.05 (15)	Ti4—O16—La1^xiv	98.71 (15)
O17^vii—Ti1—O3^vii	89.95 (15)	Ti3—O16—La1^xiv	98.96 (14)
O1^xiii—Ti1—O3^viii	91.94 (16)	Ti4—O16—La2	98.73 (14)
O1—Ti1—O3^viii	88.06 (16)	Ti3—O16—La2	98.10 (15)
O17^viii—Ti1—O3^viii	89.95 (15)	La1^xiv—O16—La2	105.27 (14)
O17^vii—Ti1—O3^viii	90.05 (15)	Ti2^xx—O17—Ti1^xviii	163.5 (2)
O3^vii—Ti1—O3^viii	180.00 (13)	Ti2^xx—O17—La1^v	98.38 (14)
O2—Ti2—O2^xvi	180.0 (3)	Ti1^xviii—O17—La1^v	98.05 (14)
O2—Ti2—O17^xi	89.67 (16)	Ti2^xx—O17—La3^xviii	88.35 (13)
O2^xvi—Ti2—O17^xi	90.33 (16)	Ti1^xviii—O17—La3^xviii	88.09 (13)
O2—Ti2—O17^viii	90.33 (16)	La1^v—O17—La3^xviii	97.25 (13)
O2^xvi—Ti2—O17^viii	89.67 (16)	Ti2^xx—O17—La2^viii	90.22 (13)
O17^xi—Ti2—O17^viii	180.0 (2)	Ti1^xviii—O17—La2^viii	89.88 (13)
O2—Ti2—O4^vii	92.00 (17)	La1^v—O17—La2^viii	94.93 (12)
O2^xvi—Ti2—O4^vii	88.00 (17)	La3^xviii—O17—La2^viii	167.82 (16)
O17^xi—Ti2—O4^vii	89.97 (15)

Symmetry codes: (i) −x+1, y−1/2, −z+1/2; (ii) −x, y−1/2, −z+1/2; (iii) x, −y+1/2, z+1/2; (iv) −x+1, y−3/2, −z+1/2; (v) −x+1, y+1/2, −z+1/2; (vi) −x, y+1/2, −z+1/2; (vii) x, y−1, z; (viii) −x+1, −y+1, −z; (ix) x+1, y, z; (x) x+1, y−1, z; (xi) x−1, y−1, z; (xii) x−1, y, z; (xiii) −x+1, −y, −z; (xiv) x, −y+1/2, z−1/2; (xv) x, −y−1/2, z−1/2; (xvi) −x, −y, −z; (xvii) −x, −y+1, −z; (xviii) x, y+1, z; (xix) x−1, y+1, z; (xx) x+1, y+1, z; (xxi) −x+1, y+3/2, −z+1/2.