Lanthanum tetra­zinc, LaZn₄

The structure of lanthanum tetra­zinc, LaZn₄, has been determined from single-crystal X-ray diffraction data for the first time, approximately 70 years after its discovery. The compound exhibits a new structure type in the space group Cmcm, with one La atom and two Zn atoms occupying sites with m2m symmetry, and one Zn atom occupying a site with 2.. symmetry. The structure is closely related to the BaAl₄, La₃Al₁₁, BaNi₂Si₂ and CaCu₅ structure types, which can be presented as close-packed arrangements of 18-vertex clusters, in this case LaZn₁₈. The kindred structure types contain related 18-vertex clusters around atoms of the rare earth or alkaline earth metal.

S1. Comment

Lanthanum tetrazinc, LaZn₄, was discovered approximately 70 years ago (Rolla & Iandelli, 1941). We detected the compound during a systematic study of La–Zn and La–Zn–Sn alloys with a high content of Zn. Previous data by Bruzzone et al. (1970) included determination of the unit-cell parameters for the compound and a proposal for its space group. Those results were obtained from both Gandolfi photographs of the single-crystal and powder X-ray diffraction data, but a complete description of the crystal structure was not given. Bruzzone et al. also proposed a relationship between the structure of LaZn₄ and the BaAl₄ structure type (Alberti & Andress, 1935).

The single-crystal X-ray data reported here show that the title compound crystallizes in a new structure type in the orthorhombic space group Cmcm (Fig. 1). The structure has four crystallographically distinct atoms, all of which occupy special equivalent positions. The La atoms (Wyckoff position 4c, site symmetry m2m) are surrounded by 18 Zn atoms. The coordination polyhedra of atoms Zn1 and Zn2 (Fig. 2) (also Wyckoff position 4c) are monocapped tetragonal antiprism [ZnLa₄Zn₅] [coordination number (CN) = 9] and bicapped tetragonal antiprism [ZnLa₅Zn₅] (CN = 10), respectively. Atom Zn3 (Wyckoff position 8e, site symmetry 2..) is enclosed in a deformed cuboctahedron [ZnLa₄Zn₈] (CN = 12).

The title compound has no isostructural intermetallic compounds. Amongst other inorganic compounds, PbSbClO₂ has a related crystal structure with the same symmetry, Pearson symbol and Wyckoff sequence (Giuseppetti & Tadini, 1973). In spite of this relationship, however, it has a significantly different b/c unit-cell parameter ratio (2.231 in PbSbClO₂ compared with 1.684 in the title compound).

The coordination polyhedron of atom La1 (Fig. 2) is the principal building block of the LaZn₄ structure. The [LaZn₁₈] polyhedra share their vertices and faces. The kindred structure types BaAl₄, La₃Al₁₁ (Gomes de Mesquita & Buschow, 1967), BaNi₂Si₂ (Dörrscheidt & Schäfer, 1980) and CaCu₅ (Nowotny, 1942) contain related 18-vertex clusters around atoms of the rare earth or alkaline earth metal (Fig. 3). All of these structures, including LaZn₄, have hexagonal channels occupied by the rare earth or alkaline earth metal. Deformation of the 18-vertex cluster in the BaAl₄ structure leads to the LaZn₄ structure, with a reduction in symmetry from I4/mmm to Cmcm (Fig. 3). Shifting of the atomic layers in the BaAl₄ structure along the a and b unit vectors leads to the BaNi₂Si₂ structure type, again with a symmetry reduction from I4/mmm to Cmcm. The structure of La₃Al₁₁ is built from two types of fragments: (i) layers of [LaAl₁₈] clusters extending along b, sharing their faces and vertices; and (ii) the remaining La atoms filling voids with 16 vertices between these layers. In this case, the symmetry is reduced from I4/mmm to Immm. Finally, rearrangement of the atoms in the fragment of the La₃Al₁₁ structure type leads to the main building block of the CaCu₅ structure type.

The electronic structure of LaZn₄ was calculated by means of the TB-LMTO-ASA program package (Andersen et al., 1986). The electron localization function (ELF) and density of states (DOS) plots show a metallic type of conductivity (Fig. 4). Amongst other La–Zn compounds, LaZn_12.37 (Oshchapovsky, Pavlyuk, Dmytriv & White, 2011) and LaZn₅ (Oshchapovsky et al., 2012) also display metallic behaviour and similar DOS plots. The main reason for such similarity is that the La atoms in LaZn_12.37, LaZn₅ and LaZn₄ have large first coordination spheres consisting of Zn atoms only. In these compounds, and also in La₅Zn₂Sn (Oshchapovsky, Pavlyuk, Dmytriv, Chumak & Ehrenberg, 2011), the less electronegative La atoms donate their electron density to the more electronegative Zn and Sn atoms. Therefore, bonds between La and Zn/Sn atoms are mostly metallic but with some ionic component. Besides the dominant metallic component, the Zn—Zn bonds in LaZn₄ also reveal a weak covalent component with an ELF density up to 0.4 (see Fig. 4 and Table 1). In particular, the Zn1—Zn2 distances show a significant contraction [2.497 (3) Å compared with 2.66 Å for twice the van der Waals radius (Gibbs et al., 1997)] and there are unusually weak La1—Zn3 bonds with moderate bond lengths [3.4278 (12) Å]. The chemical bonding (COHP curve) exhibits strongly stabilizing Zn—Zn interactions between -8 and -7 eV, arising mostly from Zn d-orbitals (Fig. 4). These interactions are between atoms Zn1 and Zn2 (-iCOHP = 1.069 eV). The interactions observed between La and Zn atoms are almost half that (Table 1) and the integrated crystal orbital Hamilton population value is equal.

Related literature

For related literature, see: Alberti & Andress (1935); Andersen et al. (1986); Berche et al. (2011, 2012); Bruzzone et al. (1970); Dörrscheidt & Schäfer (1980); Gibbs et al. (1997); Giuseppetti & Tadini (1973); Gomes & Buschow (1967); Nowotny (1942); Oshchapovsky et al. (2012); Oshchapovsky, Pavlyuk, Dmytriv & White (2011); Oshchapovsky, Pavlyuk, Dmytriv, Chumak & Ehrenberg (2011); Rolla & Iandelli (1941).

S2. Experimental

A small irregularly shaped single crystal was selected from an inhomogeneous La–Zn–Sn ternary alloy. The sample was prepared by melting stoichiometric amounts of the pure metals in an evacuated silica ampoule with subsequent annealing in a resistance furnace at 873 K for 30 d, followed by quenching in cold water. To establish that the structure of the LaZn₄ compound is not stabilized by the addition of Sn, the compound was re-synthesized by mixing stoichiometric amounts of Zn and LaZn powders with subsequent pressing into a pellet and with the same thermal treatment as described previously. Reaction between the alloy and the silica container was not observed. The resulting product contained mainly the LaZn₄ compound, together with small amounts of the compounds La₂Zn₁₇, La₃Zn₂₂, LaZn₅ and LaZn₂. This can be explained by slow flow of the chain of peritectic reactions which transform the congruent melting La₂Zn₁₇ compound into LaZn₄ (see Berche et al., 2011, 2012).

S3. Refinement

Structure solution with direct methods in space group Cmcm succeeded without problems. Initial refinement identified clearly the La and Zn atoms. In order to test for possible mixed site occupation involving Sn, test refinements were made in which the site-occupation factors for the Zn atoms were refined, but the resulting values did not differ significantly from unity.

Computing details

Data collection: CrysAlis PRO (Agilent, 2011); cell refinement: CrysAlis PRO (Agilent, 2011); data reduction: CrysAlis PRO (Agilent, 2011); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2006) and VESTA (Momma & Izumi, 2008); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures

	Fig. 1. The unit cell of LaZn4, with displacement ellipsoids drawn at the 99.9% probability level.
	Fig. 2. The coordination polyhedra for the four independent atoms.
	Fig. 3. The relationship between the LaZn4, BaAl4, La3Al11, BaNi2Si2 and CaCu5 structure types.
	Fig. 4. A section of the electron localization function (ELF), drawn parallel to the (001) plane at z = 3/4.
	Fig. 5. Density of states (DOS) plot and chemical bonding (COHP) curves.

lanthanum tetrazinc

Crystal data

LaZn4	F(000) = 708.0
Mr = 400.47	Dx = 6.647 Mg m^−3
Orthorhombic, Cmcm	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2c 2	Cell parameters from 574 reflections
a = 6.340 (2) Å	θ = 3.3–29.0°
b = 10.312 (3) Å	µ = 33.82 mm^−1
c = 6.122 (2) Å	T = 296 K
V = 400.2 (2) Å^3	Irregular, metallic grey
Z = 4	0.12 × 0.10 × 0.003 mm

Data collection

Agilent SuperNova Dual (Cu at zero) diffractometer with Atlas detector	271 independent reflections
Radiation source: SuperNova (Mo) X-ray Source	249 reflections with I > 2σ(I)
Mirror monochromator	Rint = 0.055
Detector resolution: 10.3468 pixels mm^-1	θmax = 27.4°, θmin = 3.8°
ω scans	h = −6→8
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011)	k = −12→13
Tmin = 0.028, Tmax = 1.000	l = −7→7
1354 measured reflections

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Primary atom site location: structure-invariant direct methods
R[F^2 > 2σ(F^2)] = 0.043	Secondary atom site location: difference Fourier map
wR(F^2) = 0.112	w = 1/[σ^2(Fo^2) + (0.0761P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max < 0.001
270 reflections	Δρmax = 2.53 e Å^−3
18 parameters	Δρmin = −2.15 e Å^−3

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	0.0000	0.73467 (9)	0.2500	0.0173 (4)
Zn1	0.0000	0.14879 (18)	0.2500	0.0206 (6)
Zn2	0.0000	0.39093 (19)	0.2500	0.0224 (6)
Zn3	0.2186 (3)	0.0000	0.0000	0.0216 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
La1	0.0213 (7)	0.0140 (6)	0.0166 (6)	0.000	0.000	0.000
Zn1	0.0266 (12)	0.0168 (11)	0.0183 (9)	0.000	0.000	0.000
Zn2	0.0275 (12)	0.0193 (11)	0.0204 (10)	0.000	0.000	0.000
Zn3	0.0276 (9)	0.0103 (7)	0.0268 (8)	0.000	0.000	0.0018 (5)

Geometric parameters (Å, º)

La1—Zn1^i	3.2885 (12)	Zn1—La1^xiii	3.2912 (12)
La1—Zn1^ii	3.2885 (12)	Zn1—La1^xiv	3.2912 (12)
La1—Zn1^iii	3.2912 (12)	Zn2—Zn3^vii	2.6055 (14)
La1—Zn1^iv	3.2912 (12)	Zn2—Zn3^iii	2.6055 (14)
La1—Zn2^ii	3.3238 (13)	Zn2—Zn3^v	2.6055 (14)
La1—Zn2^i	3.3238 (13)	Zn2—Zn3^vi	2.6055 (14)
La1—Zn3^iii	3.3734 (12)	Zn2—La1^ii	3.3238 (13)
La1—Zn3^v	3.3734 (12)	Zn2—La1^i	3.3238 (13)
La1—Zn3^vi	3.3734 (12)	Zn3—Zn1^x	2.5725 (15)
La1—Zn3^vii	3.3734 (12)	Zn3—Zn2^xiii	2.6055 (14)
La1—Zn3^viii	3.4278 (12)	Zn3—Zn2^vi	2.6055 (14)
La1—Zn3^ix	3.4278 (12)	Zn3—Zn3^x	2.772 (3)
Zn1—Zn2	2.497 (3)	Zn3—Zn3^xi	3.0610 (11)
Zn1—Zn3^x	2.5725 (15)	Zn3—Zn3^xv	3.0610 (11)
Zn1—Zn3	2.5725 (15)	Zn3—La1^xiii	3.3734 (12)
Zn1—Zn3^xi	2.5725 (15)	Zn3—La1^vi	3.3734 (12)
Zn1—Zn3^xii	2.5725 (15)	Zn3—La1^xvi	3.4278 (12)
Zn1—La1^i	3.2885 (12)	Zn3—La1^ii	3.4278 (12)
Zn1—La1^ii	3.2885 (12)
Zn1^i—La1—Zn1^ii	137.13 (6)	La1^xiii—Zn1—La1^xiv	148.78 (8)
Zn1^i—La1—Zn1^iii	95.64 (2)	Zn1—Zn2—Zn3^vii	115.57 (4)
Zn1^ii—La1—Zn1^iii	95.64 (2)	Zn1—Zn2—Zn3^iii	115.57 (4)
Zn1^i—La1—Zn1^iv	95.64 (2)	Zn3^vii—Zn2—Zn3^iii	128.85 (8)
Zn1^ii—La1—Zn1^iv	95.64 (2)	Zn1—Zn2—Zn3^v	115.57 (4)
Zn1^iii—La1—Zn1^iv	148.78 (8)	Zn3^vii—Zn2—Zn3^v	86.40 (7)
Zn1^i—La1—Zn2^ii	178.50 (4)	Zn3^iii—Zn2—Zn3^v	71.95 (5)
Zn1^ii—La1—Zn2^ii	44.37 (5)	Zn1—Zn2—Zn3^vi	115.57 (4)
Zn1^iii—La1—Zn2^ii	83.981 (19)	Zn3^vii—Zn2—Zn3^vi	71.95 (5)
Zn1^iv—La1—Zn2^ii	83.981 (19)	Zn3^iii—Zn2—Zn3^vi	86.40 (7)
Zn1^i—La1—Zn2^i	44.37 (5)	Zn3^v—Zn2—Zn3^vi	128.85 (8)
Zn1^ii—La1—Zn2^i	178.50 (4)	Zn1—Zn2—La1^ii	67.07 (3)
Zn1^iii—La1—Zn2^i	83.981 (19)	Zn3^vii—Zn2—La1^ii	135.17 (3)
Zn1^iv—La1—Zn2^i	83.981 (19)	Zn3^iii—Zn2—La1^ii	68.11 (2)
Zn2^ii—La1—Zn2^i	134.13 (6)	Zn3^v—Zn2—La1^ii	135.17 (3)
Zn1^i—La1—Zn3^iii	133.19 (3)	Zn3^vi—Zn2—La1^ii	68.11 (2)
Zn1^ii—La1—Zn3^iii	80.78 (3)	Zn1—Zn2—La1^i	67.07 (3)
Zn1^iii—La1—Zn3^iii	45.39 (4)	Zn3^vii—Zn2—La1^i	68.11 (2)
Zn1^iv—La1—Zn3^iii	108.43 (5)	Zn3^iii—Zn2—La1^i	135.17 (3)
Zn2^ii—La1—Zn3^iii	45.78 (3)	Zn3^v—Zn2—La1^i	68.11 (2)
Zn2^i—La1—Zn3^iii	97.95 (3)	Zn3^vi—Zn2—La1^i	135.17 (3)
Zn1^i—La1—Zn3^v	80.78 (3)	La1^ii—Zn2—La1^i	134.13 (6)
Zn1^ii—La1—Zn3^v	133.19 (3)	Zn1—Zn2—La1	180.0
Zn1^iii—La1—Zn3^v	45.39 (4)	Zn3^vii—Zn2—La1	64.43 (4)
Zn1^iv—La1—Zn3^v	108.43 (5)	Zn3^iii—Zn2—La1	64.43 (4)
Zn2^ii—La1—Zn3^v	97.95 (3)	Zn3^v—Zn2—La1	64.43 (4)
Zn2^i—La1—Zn3^v	45.78 (3)	Zn3^vi—Zn2—La1	64.43 (4)
Zn3^iii—La1—Zn3^v	53.96 (3)	La1^ii—Zn2—La1	112.93 (3)
Zn1^i—La1—Zn3^vi	133.19 (3)	La1^i—Zn2—La1	112.93 (3)
Zn1^ii—La1—Zn3^vi	80.78 (3)	Zn1—Zn2—La1^xiv	63.06 (4)
Zn1^iii—La1—Zn3^vi	108.43 (5)	Zn3^vii—Zn2—La1^xiv	143.69 (2)
Zn1^iv—La1—Zn3^vi	45.39 (3)	Zn3^iii—Zn2—La1^xiv	65.50 (3)
Zn2^ii—La1—Zn3^vi	45.78 (3)	Zn3^v—Zn2—La1^xiv	65.50 (3)
Zn2^i—La1—Zn3^vi	97.95 (3)	Zn3^vi—Zn2—La1^xiv	143.69 (2)
Zn3^iii—La1—Zn3^vi	63.84 (6)	La1^ii—Zn2—La1^xiv	79.83 (2)
Zn3^v—La1—Zn3^vi	88.33 (5)	La1^i—Zn2—La1^xiv	79.83 (2)
Zn1^i—La1—Zn3^vii	80.78 (3)	La1—Zn2—La1^xiv	116.94 (4)
Zn1^ii—La1—Zn3^vii	133.19 (3)	Zn1—Zn2—La1^xiii	63.06 (4)
Zn1^iii—La1—Zn3^vii	108.43 (5)	Zn3^vii—Zn2—La1^xiii	65.50 (3)
Zn1^iv—La1—Zn3^vii	45.39 (4)	Zn3^iii—Zn2—La1^xiii	143.69 (2)
Zn2^ii—La1—Zn3^vii	97.95 (3)	Zn3^v—Zn2—La1^xiii	143.69 (2)
Zn2^i—La1—Zn3^vii	45.78 (3)	Zn3^vi—Zn2—La1^xiii	65.50 (3)
Zn3^iii—La1—Zn3^vii	88.33 (5)	La1^ii—Zn2—La1^xiii	79.83 (2)
Zn3^v—La1—Zn3^vii	63.84 (6)	La1^i—Zn2—La1^xiii	79.83 (2)
Zn3^vi—La1—Zn3^vii	53.96 (3)	La1—Zn2—La1^xiii	116.94 (4)
Zn1^i—La1—Zn3^viii	44.98 (3)	La1^xiv—Zn2—La1^xiii	126.11 (7)
Zn1^ii—La1—Zn3^viii	97.12 (4)	Zn1^x—Zn3—Zn1	114.79 (7)
Zn1^iii—La1—Zn3^viii	127.18 (5)	Zn1^x—Zn3—Zn2^xiii	117.45 (6)
Zn1^iv—La1—Zn3^viii	79.94 (4)	Zn1—Zn3—Zn2^xiii	106.07 (3)
Zn2^ii—La1—Zn3^viii	136.24 (3)	Zn1^x—Zn3—Zn2^vi	106.07 (3)
Zn2^i—La1—Zn3^viii	84.25 (3)	Zn1—Zn3—Zn2^vi	117.45 (6)
Zn3^iii—La1—Zn3^viii	171.48 (5)	Zn2^xiii—Zn3—Zn2^vi	93.60 (7)
Zn3^v—La1—Zn3^viii	125.72 (2)	Zn1^x—Zn3—Zn3^x	57.40 (4)
Zn3^vi—La1—Zn3^viii	124.15 (2)	Zn1—Zn3—Zn3^x	57.40 (4)
Zn3^vii—La1—Zn3^viii	98.98 (2)	Zn2^xiii—Zn3—Zn3^x	133.20 (4)
Zn1^i—La1—Zn3^ix	97.12 (4)	Zn2^vi—Zn3—Zn3^x	133.20 (4)
Zn1^ii—La1—Zn3^ix	44.98 (3)	Zn1^x—Zn3—Zn3^xi	126.51 (3)
Zn1^iii—La1—Zn3^ix	127.18 (5)	Zn1—Zn3—Zn3^xi	53.49 (3)
Zn1^iv—La1—Zn3^ix	79.94 (4)	Zn2^xiii—Zn3—Zn3^xi	54.03 (2)
Zn2^ii—La1—Zn3^ix	84.25 (3)	Zn2^vi—Zn3—Zn3^xi	125.97 (2)
Zn2^i—La1—Zn3^ix	136.24 (3)	Zn3^x—Zn3—Zn3^xi	90.0
Zn3^iii—La1—Zn3^ix	125.72 (2)	Zn1^x—Zn3—Zn3^xv	53.49 (3)
Zn3^v—La1—Zn3^ix	171.48 (5)	Zn1—Zn3—Zn3^xv	126.51 (3)
Zn3^vi—La1—Zn3^ix	98.98 (2)	Zn2^xiii—Zn3—Zn3^xv	125.97 (2)
Zn3^vii—La1—Zn3^ix	124.15 (2)	Zn2^vi—Zn3—Zn3^xv	54.03 (2)
Zn3^viii—La1—Zn3^ix	53.04 (3)	Zn3^x—Zn3—Zn3^xv	90.0
Zn2—Zn1—Zn3^x	126.61 (4)	Zn3^xi—Zn3—Zn3^xv	180.00 (6)
Zn2—Zn1—Zn3	126.61 (4)	Zn1^x—Zn3—La1^xiii	169.31 (3)
Zn3^x—Zn1—Zn3	65.21 (7)	Zn1—Zn3—La1^xiii	65.62 (3)
Zn2—Zn1—Zn3^xi	126.61 (4)	Zn2^xiii—Zn3—La1^xiii	71.41 (6)
Zn3^x—Zn1—Zn3^xi	106.78 (8)	Zn2^vi—Zn3—La1^xiii	66.10 (4)
Zn3—Zn1—Zn3^xi	73.02 (5)	Zn3^x—Zn3—La1^xiii	121.92 (3)
Zn2—Zn1—Zn3^xii	126.61 (4)	Zn3^xi—Zn3—La1^xiii	63.018 (13)
Zn3^x—Zn1—Zn3^xii	73.02 (5)	Zn3^xv—Zn3—La1^xiii	116.982 (13)
Zn3—Zn1—Zn3^xii	106.78 (8)	Zn1^x—Zn3—La1^vi	65.62 (3)
Zn3^xi—Zn1—Zn3^xii	65.21 (7)	Zn1—Zn3—La1^vi	169.31 (3)
Zn2—Zn1—La1^i	68.57 (3)	Zn2^xiii—Zn3—La1^vi	66.10 (4)
Zn3^x—Zn1—La1^i	140.51 (3)	Zn2^vi—Zn3—La1^vi	71.41 (6)
Zn3—Zn1—La1^i	140.51 (3)	Zn3^x—Zn3—La1^vi	121.92 (3)
Zn3^xi—Zn1—La1^i	70.38 (2)	Zn3^xi—Zn3—La1^vi	116.982 (13)
Zn3^xii—Zn1—La1^i	70.38 (2)	Zn3^xv—Zn3—La1^vi	63.018 (13)
Zn2—Zn1—La1^ii	68.57 (3)	La1^xiii—Zn3—La1^vi	116.16 (6)
Zn3^x—Zn1—La1^ii	70.38 (2)	Zn1^x—Zn3—La1^xvi	64.64 (4)
Zn3—Zn1—La1^ii	70.38 (2)	Zn1—Zn3—La1^xvi	89.57 (5)
Zn3^xi—Zn1—La1^ii	140.51 (3)	Zn2^xiii—Zn3—La1^xvi	70.73 (3)
Zn3^xii—Zn1—La1^ii	140.51 (3)	Zn2^vi—Zn3—La1^xvi	152.09 (6)
La1^i—Zn1—La1^ii	137.13 (6)	Zn3^x—Zn3—La1^xvi	66.15 (3)
Zn2—Zn1—La1^xiii	74.39 (4)	Zn3^xi—Zn3—La1^xvi	63.480 (13)
Zn3^x—Zn1—La1^xiii	132.80 (5)	Zn3^xv—Zn3—La1^xvi	116.520 (13)
Zn3—Zn1—La1^xiii	68.99 (3)	La1^xiii—Zn3—La1^xvi	125.72 (2)
Zn3^xi—Zn1—La1^xiii	68.99 (3)	La1^vi—Zn3—La1^xvi	81.02 (2)
Zn3^xii—Zn1—La1^xiii	132.80 (5)	Zn1^x—Zn3—La1^ii	89.57 (5)
La1^i—Zn1—La1^xiii	84.36 (2)	Zn1—Zn3—La1^ii	64.64 (4)
La1^ii—Zn1—La1^xiii	84.36 (2)	Zn2^xiii—Zn3—La1^ii	152.09 (6)
Zn2—Zn1—La1^xiv	74.39 (4)	Zn2^vi—Zn3—La1^ii	70.73 (3)
Zn3^x—Zn1—La1^xiv	68.99 (3)	Zn3^x—Zn3—La1^ii	66.15 (3)
Zn3—Zn1—La1^xiv	132.80 (5)	Zn3^xi—Zn3—La1^ii	116.520 (13)
Zn3^xi—Zn1—La1^xiv	132.80 (5)	Zn3^xv—Zn3—La1^ii	63.480 (13)
Zn3^xii—Zn1—La1^xiv	68.99 (3)	La1^xiii—Zn3—La1^ii	81.02 (2)
La1^i—Zn1—La1^xiv	84.36 (2)	La1^vi—Zn3—La1^ii	125.72 (2)
La1^ii—Zn1—La1^xiv	84.36 (2)	La1^xvi—Zn3—La1^ii	132.29 (6)

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