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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.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270112020367/bi3038sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270112020367/bi3038Isup2.hkl
Contains datablock I

Comment top

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, LaZn12.37 (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 LaZn12.37, 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 top

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).

Experimental top

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).

Refinement top

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 top

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 top
[Figure 1] Fig. 1. The unit cell of LaZn4, with displacement ellipsoids drawn at the 99.9% probability level.
[Figure 2] Fig. 2. The coordination polyhedra for the four independent atoms.
[Figure 3] Fig. 3. The relationship between the LaZn4, BaAl4, La3Al11, BaNi2Si2 and CaCu5 structure types.
[Figure 4] Fig. 4. A section of the electron localization function (ELF), drawn parallel to the (001) plane at z = 3/4.
[Figure 5] Fig. 5. Density of states (DOS) plot and chemical bonding (COHP) curves.
lanthanum tetrazinc top
Crystal data top
LaZn4F(000) = 708.0
Mr = 400.47Dx = 6.647 Mg m3
Orthorhombic, CmcmMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2c 2Cell parameters from 574 reflections
a = 6.340 (2) Åθ = 3.3–29.0°
b = 10.312 (3) ŵ = 33.82 mm1
c = 6.122 (2) ÅT = 296 K
V = 400.2 (2) Å3Irregular, metallic grey
Z = 40.12 × 0.10 × 0.003 mm
Data collection top
Agilent SuperNova Dual (Cu at zero)
diffractometer with Atlas detector
271 independent reflections
Radiation source: SuperNova (Mo) X-ray Source249 reflections with I > 2σ(I)
Mirror monochromatorRint = 0.055
Detector resolution: 10.3468 pixels mm-1θmax = 27.4°, θmin = 3.8°
ω scansh = 68
Absorption correction: multi-scan
(CrysAlis PRO; Agilent, 2011)
k = 1213
Tmin = 0.028, Tmax = 1.000l = 77
1354 measured reflections
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullPrimary atom site location: structure-invariant direct methods
R[F2 > 2σ(F2)] = 0.043Secondary atom site location: difference Fourier map
wR(F2) = 0.112 w = 1/[σ2(Fo2) + (0.0761P)2]
where P = (Fo2 + 2Fc2)/3
S = 1.08(Δ/σ)max < 0.001
270 reflectionsΔρmax = 2.53 e Å3
18 parametersΔρmin = 2.15 e Å3
Crystal data top
LaZn4V = 400.2 (2) Å3
Mr = 400.47Z = 4
Orthorhombic, CmcmMo Kα radiation
a = 6.340 (2) ŵ = 33.82 mm1
b = 10.312 (3) ÅT = 296 K
c = 6.122 (2) Å0.12 × 0.10 × 0.003 mm
Data collection top
Agilent SuperNova Dual (Cu at zero)
diffractometer with Atlas detector
271 independent reflections
Absorption correction: multi-scan
(CrysAlis PRO; Agilent, 2011)
249 reflections with I > 2σ(I)
Tmin = 0.028, Tmax = 1.000Rint = 0.055
1354 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.04318 parameters
wR(F2) = 0.1120 restraints
S = 1.08Δρmax = 2.53 e Å3
270 reflectionsΔρmin = 2.15 e Å3
Special details top

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*/Ueq
La10.00000.73467 (9)0.25000.0173 (4)
Zn10.00000.14879 (18)0.25000.0206 (6)
Zn20.00000.39093 (19)0.25000.0224 (6)
Zn30.2186 (3)0.00000.00000.0216 (5)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
La10.0213 (7)0.0140 (6)0.0166 (6)0.0000.0000.000
Zn10.0266 (12)0.0168 (11)0.0183 (9)0.0000.0000.000
Zn20.0275 (12)0.0193 (11)0.0204 (10)0.0000.0000.000
Zn30.0276 (9)0.0103 (7)0.0268 (8)0.0000.0000.0018 (5)
Geometric parameters (Å, º) top
La1—Zn1i3.2885 (12)Zn1—La1xiii3.2912 (12)
La1—Zn1ii3.2885 (12)Zn1—La1xiv3.2912 (12)
La1—Zn1iii3.2912 (12)Zn2—Zn3vii2.6055 (14)
La1—Zn1iv3.2912 (12)Zn2—Zn3iii2.6055 (14)
La1—Zn2ii3.3238 (13)Zn2—Zn3v2.6055 (14)
La1—Zn2i3.3238 (13)Zn2—Zn3vi2.6055 (14)
La1—Zn3iii3.3734 (12)Zn2—La1ii3.3238 (13)
La1—Zn3v3.3734 (12)Zn2—La1i3.3238 (13)
La1—Zn3vi3.3734 (12)Zn3—Zn1x2.5725 (15)
La1—Zn3vii3.3734 (12)Zn3—Zn2xiii2.6055 (14)
La1—Zn3viii3.4278 (12)Zn3—Zn2vi2.6055 (14)
La1—Zn3ix3.4278 (12)Zn3—Zn3x2.772 (3)
Zn1—Zn22.497 (3)Zn3—Zn3xi3.0610 (11)
Zn1—Zn3x2.5725 (15)Zn3—Zn3xv3.0610 (11)
Zn1—Zn32.5725 (15)Zn3—La1xiii3.3734 (12)
Zn1—Zn3xi2.5725 (15)Zn3—La1vi3.3734 (12)
Zn1—Zn3xii2.5725 (15)Zn3—La1xvi3.4278 (12)
Zn1—La1i3.2885 (12)Zn3—La1ii3.4278 (12)
Zn1—La1ii3.2885 (12)
Zn1i—La1—Zn1ii137.13 (6)La1xiii—Zn1—La1xiv148.78 (8)
Zn1i—La1—Zn1iii95.64 (2)Zn1—Zn2—Zn3vii115.57 (4)
Zn1ii—La1—Zn1iii95.64 (2)Zn1—Zn2—Zn3iii115.57 (4)
Zn1i—La1—Zn1iv95.64 (2)Zn3vii—Zn2—Zn3iii128.85 (8)
Zn1ii—La1—Zn1iv95.64 (2)Zn1—Zn2—Zn3v115.57 (4)
Zn1iii—La1—Zn1iv148.78 (8)Zn3vii—Zn2—Zn3v86.40 (7)
Zn1i—La1—Zn2ii178.50 (4)Zn3iii—Zn2—Zn3v71.95 (5)
Zn1ii—La1—Zn2ii44.37 (5)Zn1—Zn2—Zn3vi115.57 (4)
Zn1iii—La1—Zn2ii83.981 (19)Zn3vii—Zn2—Zn3vi71.95 (5)
Zn1iv—La1—Zn2ii83.981 (19)Zn3iii—Zn2—Zn3vi86.40 (7)
Zn1i—La1—Zn2i44.37 (5)Zn3v—Zn2—Zn3vi128.85 (8)
Zn1ii—La1—Zn2i178.50 (4)Zn1—Zn2—La1ii67.07 (3)
Zn1iii—La1—Zn2i83.981 (19)Zn3vii—Zn2—La1ii135.17 (3)
Zn1iv—La1—Zn2i83.981 (19)Zn3iii—Zn2—La1ii68.11 (2)
Zn2ii—La1—Zn2i134.13 (6)Zn3v—Zn2—La1ii135.17 (3)
Zn1i—La1—Zn3iii133.19 (3)Zn3vi—Zn2—La1ii68.11 (2)
Zn1ii—La1—Zn3iii80.78 (3)Zn1—Zn2—La1i67.07 (3)
Zn1iii—La1—Zn3iii45.39 (4)Zn3vii—Zn2—La1i68.11 (2)
Zn1iv—La1—Zn3iii108.43 (5)Zn3iii—Zn2—La1i135.17 (3)
Zn2ii—La1—Zn3iii45.78 (3)Zn3v—Zn2—La1i68.11 (2)
Zn2i—La1—Zn3iii97.95 (3)Zn3vi—Zn2—La1i135.17 (3)
Zn1i—La1—Zn3v80.78 (3)La1ii—Zn2—La1i134.13 (6)
Zn1ii—La1—Zn3v133.19 (3)Zn1—Zn2—La1180.0
Zn1iii—La1—Zn3v45.39 (4)Zn3vii—Zn2—La164.43 (4)
Zn1iv—La1—Zn3v108.43 (5)Zn3iii—Zn2—La164.43 (4)
Zn2ii—La1—Zn3v97.95 (3)Zn3v—Zn2—La164.43 (4)
Zn2i—La1—Zn3v45.78 (3)Zn3vi—Zn2—La164.43 (4)
Zn3iii—La1—Zn3v53.96 (3)La1ii—Zn2—La1112.93 (3)
Zn1i—La1—Zn3vi133.19 (3)La1i—Zn2—La1112.93 (3)
Zn1ii—La1—Zn3vi80.78 (3)Zn1—Zn2—La1xiv63.06 (4)
Zn1iii—La1—Zn3vi108.43 (5)Zn3vii—Zn2—La1xiv143.69 (2)
Zn1iv—La1—Zn3vi45.39 (3)Zn3iii—Zn2—La1xiv65.50 (3)
Zn2ii—La1—Zn3vi45.78 (3)Zn3v—Zn2—La1xiv65.50 (3)
Zn2i—La1—Zn3vi97.95 (3)Zn3vi—Zn2—La1xiv143.69 (2)
Zn3iii—La1—Zn3vi63.84 (6)La1ii—Zn2—La1xiv79.83 (2)
Zn3v—La1—Zn3vi88.33 (5)La1i—Zn2—La1xiv79.83 (2)
Zn1i—La1—Zn3vii80.78 (3)La1—Zn2—La1xiv116.94 (4)
Zn1ii—La1—Zn3vii133.19 (3)Zn1—Zn2—La1xiii63.06 (4)
Zn1iii—La1—Zn3vii108.43 (5)Zn3vii—Zn2—La1xiii65.50 (3)
Zn1iv—La1—Zn3vii45.39 (4)Zn3iii—Zn2—La1xiii143.69 (2)
Zn2ii—La1—Zn3vii97.95 (3)Zn3v—Zn2—La1xiii143.69 (2)
Zn2i—La1—Zn3vii45.78 (3)Zn3vi—Zn2—La1xiii65.50 (3)
Zn3iii—La1—Zn3vii88.33 (5)La1ii—Zn2—La1xiii79.83 (2)
Zn3v—La1—Zn3vii63.84 (6)La1i—Zn2—La1xiii79.83 (2)
Zn3vi—La1—Zn3vii53.96 (3)La1—Zn2—La1xiii116.94 (4)
Zn1i—La1—Zn3viii44.98 (3)La1xiv—Zn2—La1xiii126.11 (7)
Zn1ii—La1—Zn3viii97.12 (4)Zn1x—Zn3—Zn1114.79 (7)
Zn1iii—La1—Zn3viii127.18 (5)Zn1x—Zn3—Zn2xiii117.45 (6)
Zn1iv—La1—Zn3viii79.94 (4)Zn1—Zn3—Zn2xiii106.07 (3)
Zn2ii—La1—Zn3viii136.24 (3)Zn1x—Zn3—Zn2vi106.07 (3)
Zn2i—La1—Zn3viii84.25 (3)Zn1—Zn3—Zn2vi117.45 (6)
Zn3iii—La1—Zn3viii171.48 (5)Zn2xiii—Zn3—Zn2vi93.60 (7)
Zn3v—La1—Zn3viii125.72 (2)Zn1x—Zn3—Zn3x57.40 (4)
Zn3vi—La1—Zn3viii124.15 (2)Zn1—Zn3—Zn3x57.40 (4)
Zn3vii—La1—Zn3viii98.98 (2)Zn2xiii—Zn3—Zn3x133.20 (4)
Zn1i—La1—Zn3ix97.12 (4)Zn2vi—Zn3—Zn3x133.20 (4)
Zn1ii—La1—Zn3ix44.98 (3)Zn1x—Zn3—Zn3xi126.51 (3)
Zn1iii—La1—Zn3ix127.18 (5)Zn1—Zn3—Zn3xi53.49 (3)
Zn1iv—La1—Zn3ix79.94 (4)Zn2xiii—Zn3—Zn3xi54.03 (2)
Zn2ii—La1—Zn3ix84.25 (3)Zn2vi—Zn3—Zn3xi125.97 (2)
Zn2i—La1—Zn3ix136.24 (3)Zn3x—Zn3—Zn3xi90.0
Zn3iii—La1—Zn3ix125.72 (2)Zn1x—Zn3—Zn3xv53.49 (3)
Zn3v—La1—Zn3ix171.48 (5)Zn1—Zn3—Zn3xv126.51 (3)
Zn3vi—La1—Zn3ix98.98 (2)Zn2xiii—Zn3—Zn3xv125.97 (2)
Zn3vii—La1—Zn3ix124.15 (2)Zn2vi—Zn3—Zn3xv54.03 (2)
Zn3viii—La1—Zn3ix53.04 (3)Zn3x—Zn3—Zn3xv90.0
Zn2—Zn1—Zn3x126.61 (4)Zn3xi—Zn3—Zn3xv180.00 (6)
Zn2—Zn1—Zn3126.61 (4)Zn1x—Zn3—La1xiii169.31 (3)
Zn3x—Zn1—Zn365.21 (7)Zn1—Zn3—La1xiii65.62 (3)
Zn2—Zn1—Zn3xi126.61 (4)Zn2xiii—Zn3—La1xiii71.41 (6)
Zn3x—Zn1—Zn3xi106.78 (8)Zn2vi—Zn3—La1xiii66.10 (4)
Zn3—Zn1—Zn3xi73.02 (5)Zn3x—Zn3—La1xiii121.92 (3)
Zn2—Zn1—Zn3xii126.61 (4)Zn3xi—Zn3—La1xiii63.018 (13)
Zn3x—Zn1—Zn3xii73.02 (5)Zn3xv—Zn3—La1xiii116.982 (13)
Zn3—Zn1—Zn3xii106.78 (8)Zn1x—Zn3—La1vi65.62 (3)
Zn3xi—Zn1—Zn3xii65.21 (7)Zn1—Zn3—La1vi169.31 (3)
Zn2—Zn1—La1i68.57 (3)Zn2xiii—Zn3—La1vi66.10 (4)
Zn3x—Zn1—La1i140.51 (3)Zn2vi—Zn3—La1vi71.41 (6)
Zn3—Zn1—La1i140.51 (3)Zn3x—Zn3—La1vi121.92 (3)
Zn3xi—Zn1—La1i70.38 (2)Zn3xi—Zn3—La1vi116.982 (13)
Zn3xii—Zn1—La1i70.38 (2)Zn3xv—Zn3—La1vi63.018 (13)
Zn2—Zn1—La1ii68.57 (3)La1xiii—Zn3—La1vi116.16 (6)
Zn3x—Zn1—La1ii70.38 (2)Zn1x—Zn3—La1xvi64.64 (4)
Zn3—Zn1—La1ii70.38 (2)Zn1—Zn3—La1xvi89.57 (5)
Zn3xi—Zn1—La1ii140.51 (3)Zn2xiii—Zn3—La1xvi70.73 (3)
Zn3xii—Zn1—La1ii140.51 (3)Zn2vi—Zn3—La1xvi152.09 (6)
La1i—Zn1—La1ii137.13 (6)Zn3x—Zn3—La1xvi66.15 (3)
Zn2—Zn1—La1xiii74.39 (4)Zn3xi—Zn3—La1xvi63.480 (13)
Zn3x—Zn1—La1xiii132.80 (5)Zn3xv—Zn3—La1xvi116.520 (13)
Zn3—Zn1—La1xiii68.99 (3)La1xiii—Zn3—La1xvi125.72 (2)
Zn3xi—Zn1—La1xiii68.99 (3)La1vi—Zn3—La1xvi81.02 (2)
Zn3xii—Zn1—La1xiii132.80 (5)Zn1x—Zn3—La1ii89.57 (5)
La1i—Zn1—La1xiii84.36 (2)Zn1—Zn3—La1ii64.64 (4)
La1ii—Zn1—La1xiii84.36 (2)Zn2xiii—Zn3—La1ii152.09 (6)
Zn2—Zn1—La1xiv74.39 (4)Zn2vi—Zn3—La1ii70.73 (3)
Zn3x—Zn1—La1xiv68.99 (3)Zn3x—Zn3—La1ii66.15 (3)
Zn3—Zn1—La1xiv132.80 (5)Zn3xi—Zn3—La1ii116.520 (13)
Zn3xi—Zn1—La1xiv132.80 (5)Zn3xv—Zn3—La1ii63.480 (13)
Zn3xii—Zn1—La1xiv68.99 (3)La1xiii—Zn3—La1ii81.02 (2)
La1i—Zn1—La1xiv84.36 (2)La1vi—Zn3—La1ii125.72 (2)
La1ii—Zn1—La1xiv84.36 (2)La1xvi—Zn3—La1ii132.29 (6)
Symmetry codes: (i) x, y+1, z+1; (ii) x, y+1, z; (iii) x1/2, y+1/2, z; (iv) x+1/2, y+1/2, z; (v) x1/2, 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, y1/2, z; (xiv) x1/2, y1/2, z; (xv) x, y, z1/2; (xvi) x, y1, z.

Experimental details

Crystal data
Chemical formulaLaZn4
Mr400.47
Crystal system, space groupOrthorhombic, Cmcm
Temperature (K)296
a, b, c (Å)6.340 (2), 10.312 (3), 6.122 (2)
V3)400.2 (2)
Z4
Radiation typeMo Kα
µ (mm1)33.82
Crystal size (mm)0.12 × 0.10 × 0.003
Data collection
DiffractometerAgilent SuperNova Dual (Cu at zero)
diffractometer with Atlas detector
Absorption correctionMulti-scan
(CrysAlis PRO; Agilent, 2011)
Tmin, Tmax0.028, 1.000
No. of measured, independent and
observed [I > 2σ(I)] reflections
1354, 271, 249
Rint0.055
(sin θ/λ)max1)0.648
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.043, 0.112, 1.08
No. of reflections270
No. of parameters18
Δρmax, Δρmin (e Å3)2.53, 2.15

Computer programs: CrysAlis PRO (Agilent, 2011), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2006) and VESTA (Momma & Izumi, 2008), publCIF (Westrip, 2010).

Table 1. Selected bond lengths and associated bond energies top
AtomsDistance (Å)iCOHP (eV per cell)
La1—Zn1i3.2885 (12)-0.549
La1—Zn1iii3.2912 (12)-0.547
La1—Zn2i3.3238 (13)-0.521
Zn2—La13.545 (3)-0.359
Zn2—La1xiii3.5558 (14)-0.438
La1—Zn3iii3.3734 (12)-0.485
La1—Zn3viii3.4278 (12)-0.033
Zn1—Zn22.497 (3)-1.069
Zn1—Zn32.5725 (15)-0.537
Zn2—Zn3iii2.6055 (14)-0.725
Zn3—Zn3x2.772 (3)-0.495
Zn3—Zn3xi3.0610 (11)-0.381
Symmetry codes: (i) -x, -y + 1, -z + 1; (iii) x - 1/2, y + 1/2, z; (viii) x, y + 1, -z + 1/2; (x) -x, -y, -z; (xi) x, y, -z + 1/2; (xiii) x + 1/2, y - 1/2, z.
 

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