supplementary materials


Acta Cryst. (2013). E69, i36    [ doi:10.1107/S1600536813012191 ]

The low-symmetry lanthanum(III) oxotellurate(IV), La10Te12O39

P. L. Wang and Y. Mozharivskyj

Abstract top

Single crystals of decalanthanum(III) dodecaoxotellurate(IV), La10Te12O39, were obtained by reacting La2O3 and TeO2 in a CsCl flux. Its crystal structure can be viewed as a three-dimensional network of corner- and edge-sharing LaO8 polyhedra with TeIV atoms filling the interstitial sites. The TeIV atoms with their 5s2 electron lone pairs distort the LaO8 polyhedra through variable Te-O bonds. Among the six unique Te sites, four of them define empty channels extending parallel to the a axis. The formation of these channels is a result of the stereochemically active electron lone pairs on the TeIV atoms. The atomic arrangement of the Te-O units can be understood on the basis of the valence shell electron pair repulsion (VSEPR) model. A certain degree of disorder is observed in the crystal structure. As a result, one of the five different La sites is split into two positions with an occupancy ratio of 0.875 (2):0.125 (2). Also, one of the oxygen sites is split into two positions in a 0.559 (13):0.441 (13) ratio, and one O site is half-occupied. Such disorder was observed in all measured La10Te12O39 crystals.

Comment top

A number of rare-earth(III) oxotellurates(IV), including Dy2Te3O9 (Meier et al., 2009), Nd2Te4O11 (Castro et al., 1990) and Ho2Te5O13 (Weber et al., 2001), have been prepared and structurally characterized. Despite their different compositions, these compounds all contain tellurium atoms in the oxidation state +IV. The remaining two electrons on the TeIV atoms usually form stereo-chemically active but chemically non-bonding electron lone pairs. The local atomic arrangements around these TeIV atoms with electron lone pairs can be understood on basis of the 'Valence Shell Electron Pair Repulsion' (VSEPR) model (Gillespie, 1970). As the local symmetry of the TeIV sites is reduced by the lone pairs, these compounds usually adopt low-symmetry space groups, e.g. C2/c for Nd2Te4O11, P1 for Ho2Te5O13 or P21/c for Dy2Te3O9. The title compound, La10Te12O39, can be considered as another member of the rare-earth(III) oxotellurates(IV) family. Structural similarities can be observed between La10Te12O39 and other rare-earth(III) oxotellurates(IV), including the distorted LaO8 polyhedra and a number of different Te–O structural motifs. Among the six Te atoms in the unit cell, four of them define empty channels parallel to the a-axis, while the other two fill the interstitial positions between the LaO8 polyhedra (Fig. 1).

If Te–O distances 2.03 Å (sum of the Te and O covalent radii) are considered as primary Te–O bonds, three TeO3 units (for Te1, Te4 and Te6) can be identified. Also, a fourth long Te–O interaction is observed for each of these three Te atoms (the fourth oxygen atoms is 2.852 (6) Å from Te1, 2.923 (8) Å from Te4 and 2.802 (6) Å from Te6). Bond valence sum calculations (Brown, 2009) show a minimal contribution from these long interactions; when these interactions are discarded, the bond valence sums for the 3-coordinated Te1, Te4 and Te6 atoms are close to 4.0 valence units (v.u.). The other three Te atoms (Te2, Te3 and Te5) display shorter secondary Te–O interactions ( 2.5 Å), which allow them to form TeO4 units in distorted seesaw configurations. The bond valence sums indicate significant contributions from these interactions. For these TeO4 units, bond valence sum are 3.9 v.u, 3.9 v.u and 4.4 v.u for Te2, Te3 and Te5, respectively. Such results are consistent with the assignment of oxidation state +IV for the Te atoms.

The competition between the Te2 and Te5 atoms to form stronger interactions with the bridging oxygen atom (O19) also causes disorder on the oxygen site. As a result, O19 is split into two separated oxygen positions (O191 and O192) to account for the electron density distribution. In addition to the disordered oxygen sites, one of the lanthanum sites (La5) is also described by split positions (La51 and La52). Such disorder could be a consequence of the asymmetric environment in the distorted LaO8 polyhedron.

Related literature top

For the structures of related rare-earth oxotellurates(IV), see: Castro et al. (1990); Weber et al. (2001); Meier et al. (2009). For synthetic details, see: Weber & Schleid (2000). For standardization of structural data, see: (Gelato & Parthé, 1987). For the VSEPR model, see: Gillespie (1970). For the bond-valence method, see: Brown (2009).

Experimental top

Single crystals of La10Te12O39 were obtained by reacting La2O3 (99.99 wt. %, Rhône-Poulenc, pre-fired at 1273 K for 12 h) and TeO2 (99.99%, Johnson Matthey Electronics) in a CsCl (99.9%, Alfa-Aesar) flux (Weber & Schleid, 2000). In total, 0.1 gram of the La2O3 and TeO2 powder with the 1:2 molar ratio were ground and mixed with 1.9 grams of CsCl. The sample mixture was placed in an alumina crucible, which was sealed in a silica tube under vacuum. The sample was heated to 1273 K at a rate of 50 K/h. After holding at 1273 K for 72 h, the temperature was then slowly decreased to 1073 K at a rate of 5 K/hour. After annealing at 1073 K for 20 h, the sample was quenched in air. Transparent, colorless, needle-shaped single crystals were obtained by washing away the salt flux with distilled water and ethanol.

Refinement top

The structure was standardized by using the STRUCTURE TIDY program (Gelato & Parthé, 1987). Two pairs of split positions, La51/La52 and O191/O192 were modelled to account for the observed electron density distribution. Between each pair of spilt sites, the sum of their occupancies was constrained to 100%, while the isotropic or anisotropic displacement parameters were equalized using the EADP command. The occupancies of each site was extracted from the refinement. Deficiency on the O20 site was observed during the refinement. The occupancy of the O20 site was later assigned to 50% to account for charge balance. The remaining maximum and minimum electron densities (3.71 e- Å-3 and -3.98 e- Å-3) are 0.62 Å and 0.24 Å, respectively, from atom Te5.

Computing details top

Data collection: X-AREA (Stoe, 2004); cell refinement: X-AREA (Stoe, 2004); data reduction: X-RED32 (Stoe, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Crystal Impact, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The crystal structure of La10Te12O39 represented with displacement ellipsoids at the 90% probability level.
Decalanthanum dodecatellurium triacontnonaoxide top
Crystal data top
La10Te12O39Z = 1
Mr = 3544.30F(000) = 1506
Triclinic, P1Dx = 5.843 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 5.6856 (11) ÅCell parameters from 18743 reflections
b = 12.621 (3) Åθ = 2.9–36.9°
c = 14.402 (3) ŵ = 18.98 mm1
α = 95.53 (3)°T = 293 K
β = 100.88 (3)°Needle, colourless
γ = 93.13 (3)°0.12 × 0.04 × 0.02 mm
V = 1007.3 (3) Å3
Data collection top
Stoe IPDSII
diffractometer
8922 independent reflections
Radiation source: fine-focus sealed tube5110 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.063
ω–scanθmax = 36.3°, θmin = 2.9°
Absorption correction: numerical
(X-SHAPE and X-RED32; Stoe, 2004)
h = 96
Tmin = 0.256, Tmax = 0.702k = 2120
18743 measured reflectionsl = 2323
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.042 w = 1/[σ2(Fo2) + (0.0122P)2]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.064(Δ/σ)max = 0.003
S = 0.77Δρmax = 3.71 e Å3
8922 reflectionsΔρmin = 3.98 e Å3
289 parametersExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 0.00195 (3)
Crystal data top
La10Te12O39γ = 93.13 (3)°
Mr = 3544.30V = 1007.3 (3) Å3
Triclinic, P1Z = 1
a = 5.6856 (11) ÅMo Kα radiation
b = 12.621 (3) ŵ = 18.98 mm1
c = 14.402 (3) ÅT = 293 K
α = 95.53 (3)°0.12 × 0.04 × 0.02 mm
β = 100.88 (3)°
Data collection top
Stoe IPDSII
diffractometer
8922 independent reflections
Absorption correction: numerical
(X-SHAPE and X-RED32; Stoe, 2004)
5110 reflections with I > 2σ(I)
Tmin = 0.256, Tmax = 0.702Rint = 0.063
18743 measured reflectionsθmax = 36.3°
Refinement top
R[F2 > 2σ(F2)] = 0.042Δρmax = 3.71 e Å3
wR(F2) = 0.064Δρmin = 3.98 e Å3
S = 0.77Absolute structure: ?
8922 reflectionsFlack parameter: ?
289 parametersRogers parameter: ?
0 restraints
Special details top

Experimental. A numerical absorption correction was based on the crystal shape that was originally derived from the optical face indexing but later optimized against equivalent reflections using Stoe X-SHAPE software (Stoe & Cie GmbH, 2004)

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 (Å2) top
xyzUiso*/UeqOcc. (<1)
La10.42088 (10)0.52484 (4)0.35191 (3)0.00809 (10)
La20.54271 (10)0.15044 (4)0.55453 (3)0.01179 (12)
La30.79356 (10)0.07556 (4)0.08168 (3)0.00813 (9)
La40.81948 (10)0.38287 (4)0.17100 (4)0.01151 (11)
La510.93544 (12)0.03921 (6)0.37049 (5)0.01013 (15)0.875 (2)
La520.9564 (9)0.0092 (4)0.3946 (4)0.01013 (15)0.125 (2)
Te10.03902 (11)0.34576 (4)0.44123 (4)0.01010 (11)
Te20.10966 (12)0.29104 (6)0.71241 (4)0.01761 (14)
Te30.22321 (11)0.24798 (5)0.00280 (4)0.00909 (11)
Te40.48089 (10)0.20819 (4)0.28804 (4)0.01029 (11)
Te50.33718 (14)0.55670 (7)0.09840 (5)0.02424 (16)
Te60.28887 (10)0.90925 (4)0.18953 (3)0.00793 (10)
O10.0464 (12)0.8560 (5)0.3423 (5)0.0228 (15)
O20.0751 (13)0.2551 (6)0.1077 (5)0.0248 (15)
O30.0812 (11)0.3836 (5)0.3226 (4)0.0165 (13)
O40.0853 (11)0.1040 (5)0.9697 (4)0.0157 (13)
O50.0957 (12)0.0194 (5)0.2117 (4)0.0157 (13)
O60.1285 (13)0.6544 (6)0.3738 (4)0.0217 (14)
O70.1599 (13)0.5237 (5)0.1880 (4)0.0202 (14)
O80.1863 (14)0.2177 (6)0.4339 (5)0.0243 (15)
O90.2484 (11)0.0094 (5)0.4996 (4)0.0153 (13)
O100.3008 (13)0.4396 (6)0.4992 (4)0.0238 (16)
O110.3612 (12)0.2841 (5)0.6470 (4)0.0193 (13)
O120.4366 (11)0.9645 (5)0.0960 (4)0.0166 (12)
O130.4386 (16)0.4258 (8)0.0647 (5)0.039 (2)
O140.4707 (11)0.0531 (5)0.7030 (4)0.0195 (14)
O150.5313 (11)0.2219 (5)0.0575 (5)0.0253 (16)
O160.5651 (11)0.3536 (5)0.2926 (4)0.0139 (12)
O170.6547 (11)0.1833 (5)0.4068 (4)0.0139 (12)
O180.7421 (12)0.1666 (6)0.2342 (4)0.0207 (13)
O1910.290 (2)0.4482 (9)0.7515 (8)0.0153 (18)0.559 (13)
O1920.382 (3)0.4438 (11)0.8010 (10)0.0153 (18)0.441 (13)
O200.916 (3)0.4450 (15)0.0126 (8)0.032 (4)0.50
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
La10.0086 (2)0.0071 (2)0.00811 (18)0.00113 (17)0.00047 (17)0.00086 (15)
La20.0160 (3)0.0123 (2)0.0099 (2)0.0065 (2)0.0060 (2)0.00511 (16)
La30.0085 (2)0.00864 (19)0.00750 (17)0.00180 (17)0.00207 (15)0.00023 (14)
La40.0087 (2)0.0109 (2)0.0138 (2)0.00191 (17)0.00131 (18)0.00210 (17)
La510.0097 (2)0.0098 (3)0.0121 (3)0.0027 (2)0.0034 (2)0.0037 (2)
La520.0097 (2)0.0098 (3)0.0121 (3)0.0027 (2)0.0034 (2)0.0037 (2)
Te10.0108 (2)0.0096 (2)0.0100 (2)0.0011 (2)0.00199 (18)0.00261 (17)
Te20.0136 (3)0.0306 (4)0.0117 (2)0.0098 (3)0.0051 (2)0.0082 (2)
Te30.0073 (2)0.0111 (2)0.00840 (19)0.0012 (2)0.00017 (18)0.00111 (17)
Te40.0113 (2)0.0080 (2)0.0109 (2)0.00019 (19)0.00045 (18)0.00099 (16)
Te50.0210 (4)0.0329 (4)0.0213 (3)0.0096 (3)0.0112 (3)0.0031 (3)
Te60.0080 (2)0.0077 (2)0.00793 (19)0.00001 (18)0.00129 (18)0.00082 (16)
O10.015 (3)0.014 (3)0.037 (4)0.002 (2)0.004 (3)0.008 (3)
O20.028 (4)0.023 (4)0.025 (3)0.007 (3)0.019 (3)0.011 (3)
O30.016 (3)0.019 (3)0.012 (2)0.008 (2)0.003 (2)0.008 (2)
O40.012 (3)0.014 (3)0.019 (3)0.003 (2)0.002 (2)0.007 (2)
O50.022 (3)0.017 (3)0.008 (2)0.010 (3)0.001 (2)0.001 (2)
O60.026 (4)0.026 (3)0.015 (3)0.014 (3)0.003 (3)0.004 (2)
O70.022 (3)0.020 (3)0.019 (3)0.005 (3)0.000 (3)0.006 (2)
O80.030 (4)0.022 (3)0.022 (3)0.013 (3)0.001 (3)0.009 (2)
O90.011 (3)0.017 (3)0.017 (3)0.000 (2)0.003 (2)0.007 (2)
O100.024 (3)0.023 (3)0.019 (3)0.013 (3)0.007 (3)0.008 (2)
O110.022 (3)0.013 (3)0.024 (3)0.001 (3)0.011 (3)0.004 (2)
O120.011 (3)0.029 (3)0.012 (2)0.003 (3)0.004 (2)0.007 (2)
O130.038 (5)0.063 (6)0.014 (3)0.035 (4)0.005 (3)0.001 (3)
O140.015 (3)0.029 (3)0.012 (2)0.008 (3)0.005 (2)0.008 (2)
O150.009 (3)0.014 (3)0.046 (4)0.003 (2)0.011 (3)0.002 (3)
O160.014 (3)0.008 (2)0.020 (3)0.003 (2)0.001 (2)0.005 (2)
O170.019 (3)0.020 (3)0.006 (2)0.006 (2)0.006 (2)0.006 (2)
O180.022 (3)0.025 (3)0.015 (2)0.006 (3)0.005 (2)0.005 (2)
O1910.018 (5)0.011 (4)0.021 (4)0.004 (4)0.012 (4)0.002 (3)
O1920.018 (5)0.011 (4)0.021 (4)0.004 (4)0.012 (4)0.002 (3)
O200.028 (8)0.066 (11)0.010 (5)0.026 (8)0.007 (5)0.020 (6)
Geometric parameters (Å, º) top
La1—O10i2.400 (6)Te2—O1912.156 (11)
La1—O62.435 (7)Te2—O1922.488 (14)
La1—O191i2.448 (12)Te3—O151.841 (6)
La1—O162.485 (6)Te3—O21.861 (7)
La1—O32.502 (6)Te3—O4ix1.919 (6)
La1—O72.539 (6)Te3—O132.496 (10)
La1—O11i2.647 (6)Te4—O161.863 (6)
La1—O102.652 (7)Te4—O171.871 (5)
La1—O192i2.706 (15)Te4—O181.877 (7)
La2—O92.345 (6)Te5—O131.831 (9)
La2—O172.400 (6)Te5—O71.845 (7)
La2—O112.441 (6)Te5—O20vi1.936 (13)
La2—O9ii2.528 (7)Te5—O192i1.945 (15)
La2—O1i2.531 (6)Te6—O5x1.859 (7)
La2—O82.643 (6)Te6—O14i1.866 (5)
La2—O142.651 (6)Te6—O121.883 (6)
La2—O6i2.985 (7)O1—Te2viii2.032 (7)
La3—O152.447 (6)O1—La52xi2.131 (9)
La3—O182.454 (6)O1—La51xi2.446 (7)
La3—O12iii2.456 (6)O1—La2i2.531 (6)
La3—O5iv2.477 (6)O2—La4xii2.453 (8)
La3—O4ii2.489 (7)O2—La3xii2.655 (7)
La3—O4v2.557 (7)O3—La4xii2.398 (5)
La3—O12vi2.633 (5)O4—Te3xiii1.919 (6)
La3—O2iv2.655 (7)O4—La3ii2.489 (7)
La4—O3iv2.398 (5)O4—La3xiv2.557 (7)
La4—O2iv2.453 (8)O5—Te6iii1.859 (7)
La4—O191i2.476 (11)O5—La3xii2.477 (6)
La4—O162.513 (7)O5—La51xii2.612 (6)
La4—O7iv2.516 (7)O5—La52xii2.902 (8)
La4—O132.522 (7)O6—Te2viii1.866 (6)
La4—O192i2.556 (15)O6—La2i2.985 (7)
La4—O202.626 (13)O7—La4xii2.516 (7)
La4—O152.733 (6)O8—La51xii2.589 (7)
La4—O182.995 (7)O8—La52xii2.829 (9)
La51—O9iv2.393 (6)O9—La52xii2.023 (7)
La51—O9ii2.420 (7)O9—La52ii2.107 (9)
La51—O1vii2.446 (7)O9—La51xii2.393 (6)
La51—O14ii2.521 (6)O9—La51ii2.420 (7)
La51—O172.565 (7)O9—La2ii2.528 (7)
La51—O8iv2.589 (7)O10—La1i2.400 (6)
La51—O5iv2.612 (6)O11—La1i2.647 (6)
La51—O182.763 (7)O12—La3x2.456 (6)
La52—O9iv2.023 (7)O12—La3vi2.633 (5)
La52—O9ii2.107 (9)O14—Te6i1.866 (5)
La52—O1vii2.131 (9)O14—La51ii2.521 (6)
La52—O14ii2.604 (7)O14—La52ii2.604 (7)
La52—O8iv2.829 (9)O191—O1920.808 (16)
La52—O172.872 (8)O191—La1i2.448 (12)
La52—O5iv2.902 (8)O191—La4i2.476 (11)
Te1—O101.861 (6)O192—Te5i1.945 (15)
Te1—O81.864 (7)O192—La4i2.556 (15)
Te1—O31.872 (6)O192—La1i2.706 (15)
Te2—O111.857 (7)O20—O20xv1.75 (4)
Te2—O6viii1.866 (6)O20—Te5vi1.936 (13)
Te2—O1viii2.032 (7)
O10i—La1—O6100.8 (2)O9ii—La51—O5iv159.6 (2)
O10i—La1—O191i97.2 (3)O1vii—La51—O5iv71.5 (2)
O6—La1—O191i121.3 (3)O14ii—La51—O5iv94.0 (2)
O10i—La1—O1699.0 (2)O17—La51—O5iv122.32 (18)
O6—La1—O16156.5 (2)O8iv—La51—O5iv94.0 (2)
O191i—La1—O1668.0 (3)O9iv—La51—O18149.6 (2)
O10i—La1—O3123.0 (2)O9ii—La51—O18125.3 (2)
O6—La1—O387.4 (2)O1vii—La51—O18126.6 (2)
O191i—La1—O3126.1 (3)O14ii—La51—O1875.5 (2)
O16—La1—O371.2 (2)O17—La51—O1858.70 (18)
O10i—La1—O7168.4 (2)O8iv—La51—O1879.75 (19)
O6—La1—O775.5 (2)O5iv—La51—O1864.02 (19)
O191i—La1—O776.1 (3)O9iv—La52—O9ii86.2 (3)
O16—La1—O787.4 (2)O9iv—La52—O1vii86.6 (3)
O3—La1—O768.2 (2)O9ii—La52—O1vii108.8 (4)
O10i—La1—O11i73.2 (2)O9iv—La52—O14ii156.7 (4)
O6—La1—O11i73.3 (2)O9ii—La52—O14ii76.7 (3)
O191i—La1—O11i59.6 (3)O1vii—La52—O14ii84.1 (3)
O16—La1—O11i125.0 (2)O9iv—La52—O8iv71.1 (3)
O3—La1—O11i157.5 (2)O9ii—La52—O8iv106.8 (3)
O7—La1—O11i95.2 (2)O1vii—La52—O8iv136.2 (3)
O10i—La1—O1063.2 (3)O14ii—La52—O8iv128.9 (3)
O6—La1—O1086.3 (2)O9iv—La52—O17117.3 (3)
O191i—La1—O10149.8 (3)O9ii—La52—O1769.9 (3)
O16—La1—O1091.4 (2)O1vii—La52—O17155.5 (3)
O3—La1—O1061.16 (18)O14ii—La52—O1771.7 (2)
O7—La1—O10126.7 (2)O8iv—La52—O1762.9 (2)
O11i—La1—O10127.04 (19)O9iv—La52—O5iv110.9 (3)
O10i—La1—O192i113.7 (4)O9ii—La52—O5iv162.5 (3)
O6—La1—O192i111.4 (4)O1vii—La52—O5iv70.1 (3)
O191i—La1—O192i17.1 (4)O14ii—La52—O5iv85.8 (2)
O16—La1—O192i71.3 (3)O8iv—La52—O5iv83.1 (2)
O3—La1—O192i115.1 (3)O17—La52—O5iv103.5 (2)
O7—La1—O192i59.1 (4)O10—Te1—O8100.6 (3)
O11i—La1—O192i63.8 (3)O10—Te1—O389.4 (3)
O10—La1—O192i162.1 (4)O8—Te1—O396.2 (3)
O10i—La1—Te193.63 (16)O11—Te2—O6viii102.3 (3)
O9—La2—O1799.5 (2)O11—Te2—O1viii95.2 (3)
O9—La2—O11106.8 (2)O6viii—Te2—O1viii86.7 (3)
O17—La2—O11122.0 (2)O11—Te2—O19178.0 (4)
O9—La2—O9ii72.4 (3)O6viii—Te2—O19190.4 (4)
O17—La2—O9ii72.6 (2)O1viii—Te2—O191171.9 (4)
O11—La2—O9ii164.7 (2)O11—Te2—O19279.9 (4)
O9—La2—O1i128.0 (2)O6viii—Te2—O192108.0 (4)
O17—La2—O1i100.2 (2)O1viii—Te2—O192165.2 (4)
O11—La2—O1i102.3 (2)O191—Te2—O19218.3 (4)
O9ii—La2—O1i68.6 (2)O15—Te3—O2101.3 (3)
O9—La2—O870.7 (2)O15—Te3—O4ix99.7 (3)
O17—La2—O867.6 (2)O2—Te3—O4ix88.2 (3)
O11—La2—O873.9 (2)O15—Te3—O1373.6 (3)
O9ii—La2—O8118.8 (2)O2—Te3—O1389.1 (3)
O1i—La2—O8160.4 (2)O4ix—Te3—O13172.1 (2)
O9—La2—O1472.04 (19)O16—Te4—O1799.0 (3)
O17—La2—O14161.3 (2)O16—Te4—O1894.0 (3)
O11—La2—O1476.7 (2)O17—Te4—O1888.6 (3)
O9ii—La2—O1488.8 (2)O13—Te5—O7101.0 (4)
O1i—La2—O1474.1 (2)O13—Te5—O20vi95.8 (6)
O8—La2—O14122.3 (2)O7—Te5—O20vi100.5 (5)
O9—La2—O6i173.5 (2)O13—Te5—O192i80.4 (5)
O17—La2—O6i82.1 (2)O7—Te5—O192i86.2 (5)
O11—La2—O6i67.3 (2)O20vi—Te5—O192i172.9 (6)
O9ii—La2—O6i114.1 (2)O5x—Te6—O14i96.7 (3)
O1i—La2—O6i57.4 (2)O5x—Te6—O1299.5 (3)
O8—La2—O6i104.5 (2)O14i—Te6—O12100.2 (3)
O14—La2—O6i108.17 (17)Te2viii—O1—La52xi140.8 (4)
O15—La3—O1868.9 (2)Te2viii—O1—La51xi139.5 (3)
O15—La3—O12iii87.2 (2)La52xi—O1—La51xi11.06 (15)
O18—La3—O12iii83.6 (2)Te2viii—O1—La2i113.0 (3)
O15—La3—O5iv137.5 (2)La52xi—O1—La2i100.1 (3)
O18—La3—O5iv70.7 (2)La51xi—O1—La2i105.8 (2)
O12iii—La3—O5iv100.8 (2)Te3—O2—La4xii133.6 (4)
O15—La3—O4ii150.80 (19)Te3—O2—La3xii104.2 (3)
O18—La3—O4ii134.4 (2)La4xii—O2—La3xii101.3 (3)
O12iii—La3—O4ii80.0 (2)Te1—O3—La4xii134.1 (3)
O5iv—La3—O4ii71.1 (2)Te1—O3—La1107.3 (2)
O15—La3—O4v103.2 (2)La4xii—O3—La1113.3 (2)
O18—La3—O4v134.4 (2)Te3xiii—O4—La3ii139.3 (3)
O12iii—La3—O4v141.94 (19)Te3xiii—O4—La3xiv106.1 (3)
O5iv—La3—O4v95.7 (2)La3ii—O4—La3xiv106.7 (2)
O4ii—La3—O4v73.3 (2)Te6iii—O5—La3xii121.3 (3)
O15—La3—O12vi75.3 (2)Te6iii—O5—La51xii119.3 (3)
O18—La3—O12vi140.1 (2)La3xii—O5—La51xii109.6 (3)
O12iii—La3—O12vi77.4 (2)Te6iii—O5—La52xii109.8 (3)
O5iv—La3—O12vi147.1 (2)La3xii—O5—La52xii117.1 (3)
O4ii—La3—O12vi76.3 (2)La51xii—O5—La52xii9.51 (11)
O4v—La3—O12vi70.38 (19)Te2viii—O6—La1131.9 (3)
O15—La3—O2iv72.9 (2)Te2viii—O6—La2i101.1 (3)
O18—La3—O2iv74.6 (2)La1—O6—La2i100.1 (2)
O12iii—La3—O2iv154.5 (2)Te5—O7—La4xii128.2 (3)
O5iv—La3—O2iv84.6 (2)Te5—O7—La1112.1 (3)
O4ii—La3—O2iv124.9 (2)La4xii—O7—La1108.2 (2)
O4v—La3—O2iv60.6 (2)Te1—O8—La51xii120.8 (3)
O12vi—La3—O2iv111.4 (2)Te1—O8—La2129.5 (3)
O15—La3—Te3iv84.65 (18)La51xii—O8—La2100.7 (2)
O18—La3—Te3iv104.67 (17)Te1—O8—La52xii127.0 (4)
O12iii—La3—Te3iv165.27 (13)La51xii—O8—La52xii10.27 (10)
O5iv—La3—Te3iv93.53 (16)La2—O8—La52xii91.0 (2)
O4ii—La3—Te3iv101.55 (16)La52xii—O9—La52ii93.8 (3)
O4v—La3—Te3iv30.83 (13)La52xii—O9—La2126.6 (3)
O12vi—La3—Te3iv88.70 (14)La52ii—O9—La2108.6 (3)
O2iv—La3—Te3iv30.10 (14)La52xii—O9—La51xii10.31 (16)
O3iv—La4—O2iv87.2 (2)La52ii—O9—La51xii99.6 (3)
O3iv—La4—O191i81.8 (3)La2—O9—La51xii116.4 (3)
O2iv—La4—O191i158.2 (3)La52xii—O9—La51ii101.2 (3)
O3iv—La4—O1671.8 (2)La52ii—O9—La51ii11.21 (15)
O2iv—La4—O16126.8 (2)La2—O9—La51ii109.7 (2)
O191i—La4—O1667.2 (3)La51xii—O9—La51ii108.1 (3)
O3iv—La4—O7iv70.2 (2)La52xii—O9—La2ii103.2 (3)
O2iv—La4—O7iv88.0 (2)La52ii—O9—La2ii117.3 (3)
O191i—La4—O7iv70.6 (3)La2—O9—La2ii107.6 (3)
O16—La4—O7iv125.9 (2)La51xii—O9—La2ii107.5 (2)
O3iv—La4—O13153.1 (3)La51ii—O9—La2ii107.1 (2)
O2iv—La4—O13119.0 (2)Te1—O10—La1i139.7 (3)
O191i—La4—O1375.2 (3)Te1—O10—La1102.0 (2)
O16—La4—O1386.4 (3)La1i—O10—La1116.8 (3)
O7iv—La4—O13113.6 (3)Te2—O11—La2138.5 (3)
O3iv—La4—O192i100.2 (4)Te2—O11—La1i111.5 (3)
O2iv—La4—O192i159.8 (4)La2—O11—La1i110.0 (3)
O191i—La4—O192i18.4 (4)Te6—O12—La3x140.4 (3)
O16—La4—O192i73.4 (4)Te6—O12—La3vi117.0 (3)
O7iv—La4—O192i77.0 (4)La3x—O12—La3vi102.6 (2)
O13—La4—O192i57.4 (4)Te5—O13—Te3133.3 (4)
O3iv—La4—O20129.1 (4)Te5—O13—La4113.8 (4)
O2iv—La4—O2071.6 (4)Te3—O13—La4104.4 (3)
O191i—La4—O20101.1 (5)Te6i—O14—La51ii149.0 (3)
O16—La4—O20155.9 (3)Te6i—O14—La52ii157.7 (4)
O7iv—La4—O2063.5 (4)La51ii—O14—La52ii11.98 (12)
O13—La4—O2070.0 (4)Te6i—O14—La2112.9 (3)
O192i—La4—O2089.4 (5)La51ii—O14—La297.73 (17)
O3iv—La4—O15131.0 (2)La52ii—O14—La287.0 (2)
O2iv—La4—O1571.4 (2)Te3—O15—La3141.2 (3)
O191i—La4—O15129.5 (3)Te3—O15—La4119.0 (3)
O16—La4—O1586.3 (2)La3—O15—La499.34 (19)
O7iv—La4—O15147.7 (2)Te4—O16—La1137.7 (3)
O13—La4—O1560.4 (3)Te4—O16—La4109.3 (3)
O192i—La4—O15115.1 (4)La1—O16—La4110.7 (2)
O20—La4—O1585.9 (4)Te4—O17—La2133.5 (3)
O3iv—La4—O1873.59 (18)Te4—O17—La51105.0 (2)
O2iv—La4—O1868.6 (2)La2—O17—La51106.5 (2)
O191i—La4—O18125.1 (3)Te4—O17—La52112.6 (3)
O16—La4—O1858.79 (19)La2—O17—La5297.1 (2)
O7iv—La4—O18137.49 (19)La51—O17—La529.40 (11)
O13—La4—O18108.8 (3)Te4—O18—La3135.8 (3)
O192i—La4—O18131.5 (4)Te4—O18—La5197.8 (3)
O20—La4—O18132.5 (4)La3—O18—La51105.6 (2)
O15—La4—O1857.66 (18)Te4—O18—La492.0 (3)
O9iv—La51—O9ii71.9 (3)La3—O18—La492.5 (2)
La52—La51—O1vii49.1 (5)La51—O18—La4141.2 (2)
O9iv—La51—O1vii72.2 (2)O192—O191—Te2104.8 (14)
O9ii—La51—O1vii90.2 (2)O192—O191—La1i99.9 (15)
La52—La51—O14ii92.8 (5)Te2—O191—La1i108.9 (5)
O9iv—La51—O14ii134.6 (2)O192—O191—La4i86.4 (13)
O9ii—La51—O14ii73.25 (19)Te2—O191—La4i133.7 (6)
O1vii—La51—O14ii79.9 (2)La1i—O191—La4i113.2 (4)
La52—La51—O17119.8 (6)O191—O192—Te5i165.3 (18)
O9iv—La51—O17115.9 (2)O191—O192—Te256.9 (12)
O9ii—La51—O1771.7 (2)Te5i—O192—Te2129.3 (7)
O1vii—La51—O17155.0 (2)O191—O192—La4i75.2 (13)
O14ii—La51—O1778.4 (2)Te5i—O192—La4i108.3 (6)
La52—La51—O8iv111.1 (5)Te2—O192—La4i115.3 (6)
O9iv—La51—O8iv71.0 (2)O191—O192—La1i63.0 (14)
O9ii—La51—O8iv105.4 (2)Te5i—O192—La1i102.4 (6)
O1vii—La51—O8iv132.6 (2)Te2—O192—La1i92.3 (5)
O14ii—La51—O8iv147.3 (2)La4i—O192—La1i102.7 (5)
O17—La51—O8iv70.5 (2)O20xv—O20—Te5vi95.3 (9)
La52—La51—O5iv117.6 (5)O20xv—O20—La4133.2 (12)
O9iv—La51—O5iv109.5 (2)Te5vi—O20—La4120.3 (8)
Symmetry codes: (i) x+1, y+1, z+1; (ii) x+1, y, z+1; (iii) x, y1, z; (iv) x+1, y, z; (v) x+1, y, z1; (vi) x+1, y+1, z; (vii) x+1, y1, z; (viii) x, y+1, z+1; (ix) x, y, z1; (x) x, y+1, z; (xi) x1, y+1, z; (xii) x1, y, z; (xiii) x, y, z+1; (xiv) x1, y, z+1; (xv) x+2, y+1, z.
Acknowledgements top

This work was supported by a Discovery Grant from the Natural Sciences and Engineering Research Council of Canada and by a grant from the ACS Petroleum Research Fund.

references
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