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The new ternary lithium copper aluminide Li8Cu12+xAl6-x (x = 1.16) crystallizes in the P63/mmc space group with six independent atom positions of site symmetries \overline{3}m. (Al/Cu mixture), \overline{6}m2 (Li atoms), 3m. (Al/Cu mixture and Li atoms) and .m. (Cu atoms). The compound is a derivative of the K7Cs6 binary structure type and is related to the binary MgZn2 Laves phase and the LiCuAl2, MgCu1.07Al0.93 and Mg(Cu1-xAlx)2 (x = 0.465) ternary Laves phases. The coordination polyhedra of the atoms in this structure are icosa­hedra (Cu atoms), slightly distorted icosa­hedra and bicapped hexa­gonal anti­prisms (Al/Cu statistical mixture), and Frank-Kasper and distorted Frank-Kasper polyhedra (Li atoms). All inter­atomic distances indicate metallic type bonding.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270107065985/sq3108sup1.cif
Contains datablocks global, I, publication_text

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270107065985/sq3108Isup2.hkl
Contains datablock I

Comment top

The Li–Cu–Al system has attracted great attention since the middle of the last century, primarily due to the mechanical properties of alloys based on these components. They are widely used in industrial manufacturing of light, super-light and deformation-stable materials. They also show good prospects for taking one of the leading places in energy-saving technologies. Many papers have been dedicated to investigations of the crystal structures of intermetallides which exist in this system (Hardy & Silcock, 1955–1956; Knowles & Stobbs, 1988; van Smaalen et al., 1990; Audier et al., 1988; Guryan et al., 1988; Dubost et al., 1986; Leblanc et al., 1991).

We report here the single-crystal structure determination for the ternary compound Li8Cu12 + xAl6 - x (x = 1.16), detected during systematic investigations of the Li–Cu–Al system at 473 K. This compound represents a new structure type, which is derived from the K7Cs6 binary type (von Simon et al., 1976) by a redistribution of the occupied Wyckoff sites. The unit-cell volume of Li8Cu12 + xAl6 - x is one-sixth of that of K7Cs6. The K atom sites (2a and 12k) are now occupied by a statistical mixture of Al/Cu and Cu atoms, respectively. Two Cs positions (4f) are occupied by Li atoms and an Al/Cu statistical mixture (for simplicity, hereinafter referred to as Al1 and Al2, because more Al than Cu is situated on these sites). Another two Cs sites (2b and 2c) are now exclusively occupied by Li atoms. A clinographic projection of the Li8Cu12 + xAl6 - x unit cell and coordination polyhedra of atoms are shown in Fig. 1. The interatomic distances in the first coordination spheres of the atoms (Table 1) are in agreement with typical values for intermetallics. The coordination polyhedra of the Cu3 atoms (Wyckoff sites 12k) are icosahedra [Cu3Cu4Al3Li5]. Two types of polyhedra are observed for the Al1 and Al2 atoms on Wyckoff sites 4f and 2a, namely bicapped hexagonal antiprisms, [Al1AlCu6Li7], and slightly distorted icosahedra, [Al2Cu6Li6], respectively. The coordination spheres around the Li1 (2b) and Li2 (2c) atoms consist of 15 atoms, resulting in 15-vertex polyhedra, [Li1Cu6Li3Al6] and [Li2Cu6Li3Al6]. The Li3 atoms (4f) are characterized by 16-vertex polyhedra, [Li3Al4Cu9Li3], similar to those in Laves phases.

Both the Li8Cu12 + xAl6 - x and K7Cs6 structures are derivatives of Laves phases. The MgZn2 (Komura & Tokunaga, 1980), Mg(Cu1 - xAlx)2 (x = 0.468) and MgCu1.07Al0.93 (Kitano et al., 1977), and LiCuAl2 (van Smaalen et al., 1990) structures are similar to the title compound. The main features of all of them are channels of hexagonal prisms with Li atoms inside, hereinafter referred to as I. These channels share edges and faces with neighbouring ones, except in LiCuAl2, where only shared faces are realised by pseudo-Frank–Kasper polyhedra (coordination number 20) sharing their rhombohedral faces to form layers, which are separated by I motifs (Fig. 2). All the other structures consist of two different fragments, namely the same motif, I, and another motif, II, consisting of a pair of empty tetrahedra connected by the vertex and rotated with respect to each other through an angle of 30° (Fig. 3). Moreover, in the MgZn2 compound, each II fragment is linked with two neighbouring ones by face-forming corrugated slabs. The II motifs build up larger ring units of ten and 14 tetrahedra in Mg(Cu1 - xAlx)2 and ten and 18 tetrahedra in MgCu1.07Al0.93 around the hexagonal prisms I. In contrast, all II fragments are isolated from each other in the title compound, so that no rings of tetrahedra are formed. This is reflected in the shorter c-axis parameter, corresponding to four I motifs, but six in MgCu1.07Al0.93 and even 16 for Mg(Cu1 - xAlx)2.

Related literature top

For related literature, see: Audier et al. (1988); Dubost et al. (1986); Farrugia (1999); Gelato & Parthé (1987); Guryan et al. (1988); Hardy & Silcock (1955–1956); Kitano et al. (1977); Knowles & Stobbs (1988); Komura & Tokunaga (1980); Leblanc et al. (1991); McArdle (1996); Pauly (1966); Pauly et al. (1968); Simon et al. (1976); Smaalen et al. (1990).

Experimental top

Crystals of Li8Cu12 + xAl6 - x (x = 1.16) were obtained from an alloy which was prepared by solid-state reaction of lithium (rod, 99.9 at.%), copper (ingots, 99.999 at.%) and aluminium (ingots, 99.999 at.%) sealed under argon in a pure iron crucible and heated at 1370 K for 10 min with intensive shaking. The product was then rapidly cooled to room temperature. When the crucible was opened in an Ar-filled glove-box, metallic dark-grey plate crystals of the title compound were found in the product. The amount of Li lost during sample preparation in hermetically closed crucibles can be estimated [Value?], based on previous studies with successive detailed chemical analyses of similar systems (Pauly, 1966; Pauly et al., 1968).

Refinement top

Analyses of the systematic absences for single-crystal data using the program ABSEN (McArdle, 1996) led to the possible space groups P31c (No. 163), P31c (No. 159), P63/mmc (No. 194), P63mc (No. 186) and P62c (No. 190). A statistical test of the distribution of the E values using the program E-STATS from the WinGX system (Farrugia, 1999) suggested that the structure is centrosymmetric (probability 61.56%). Initial positions of heavier atoms were taken from direct methods. Later, the largest remaining peaks in the difference Fourier syntheses were assumed to correspond to the Li atoms. A decrease of residual R factors and an absence of other substantial peaks in the Fourier syntheses clearly indicated that the model was correct. Taking into consideration a significant divergence of the isotropic displacement parameters, it became evident that the 2a and 4f Wyckoff sites are occupied by mixtures of atoms. The best results were obtained by refining the model with Li1, Li2, Li3 and Cu3 fully occupying the 2b, 2c, 4f and 12k positions, respectively, while statistical Al/Cu mixtures were placed in the 2a and 4f sites. Because of their relatively low atomic number, an overall displacement parameter was refined for the Li atoms. In the final refinement cycles, the anisotropic displacement parameters were refined only for Cu3. The atomic coordinates were standardized using the STRUCTURE TIDY program (Gelato & Parthé, 1987). The final difference Fourier syntheses revealed no significant residual peaks; the highest maximum residual electron density is 0.88 Å from Li1 and the deepest hole is 0.84 Å from Li1.

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2004); cell refinement: CrysAlis CCD (Oxford Diffraction, 2004); data reduction: CrysAlis RED (Oxford Diffraction, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).

Figures top
[Figure 1] Fig. 1. (a) Clinographic projection of the Li8Cu12 + xAl6 - x unit-cell contents, with displacement ellipsoids drawn at the 95% probability level. (b) The unit-cell projection of the Li8Cu12 + xAl6 - x compound onto the (110) plane and coordination polyhedra of the atoms.
[Figure 2] Fig. 2. The pseudo-Frank–Kasper polyhedral layers in the LiCuAl2 structure.
[Figure 3] Fig. 3. Crystallographic relations between Li8Cu12 + xAl6 - x, MgZn2, MgCu1.07Al0.93 and Mg(Cu1 - xAlx)2 compounds.
lithium copper aluminide top
Crystal data top
Li8Cu13.16Al4.84Dx = 4.379 Mg m3
Mr = 1022.27Mo Kα radiation, λ = 0.71073 Å
Hexagonal, P63/mmcCell parameters from 188 reflections
Hall symbol: -P 6c 2cθ = 4.4–26.4°
a = 4.9351 (10) ŵ = 17.87 mm1
c = 18.380 (4) ÅT = 295 K
V = 387.68 (14) Å3Plate, metallic dark grey
Z = 10.09 × 0.05 × 0.01 mm
F(000) = 468.5
Data collection top
Oxford Diffraction Xcalibur3 CCD
diffractometer
188 independent reflections
Radiation source: fine-focus sealed tube133 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.046
ω scansθmax = 26.4°, θmin = 4.4°
Absorption correction: empirical (using intensity measurements)
(CrysAlis RED; Oxford Diffraction, 2005)
h = 36
Tmin = 0.35, Tmax = 0.83k = 56
1046 measured reflectionsl = 2217
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullPrimary atom site location: structure-invariant direct methods
R[F2 > 2σ(F2)] = 0.027Secondary atom site location: difference Fourier map
wR(F2) = 0.058 w = 1/[σ2(Fo2) + (0.0339P)2]
where P = (Fo2 + 2Fc2)/3
S = 1.00(Δ/σ)max = 0.002
188 reflectionsΔρmax = 0.88 e Å3
14 parametersΔρmin = 0.85 e Å3
Crystal data top
Li8Cu13.16Al4.84Z = 1
Mr = 1022.27Mo Kα radiation
Hexagonal, P63/mmcµ = 17.87 mm1
a = 4.9351 (10) ÅT = 295 K
c = 18.380 (4) Å0.09 × 0.05 × 0.01 mm
V = 387.68 (14) Å3
Data collection top
Oxford Diffraction Xcalibur3 CCD
diffractometer
188 independent reflections
Absorption correction: empirical (using intensity measurements)
(CrysAlis RED; Oxford Diffraction, 2005)
133 reflections with I > 2σ(I)
Tmin = 0.35, Tmax = 0.83Rint = 0.046
1046 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.02714 parameters
wR(F2) = 0.0580 restraints
S = 1.00Δρmax = 0.88 e Å3
188 reflectionsΔρmin = 0.85 e Å3
Special details top

Experimental. A single-crystal, suitable for X-ray diffraction analysis, with the reported composition was selected under a light microscope from a bulk material with the somewhat different composition of 65 at.% of Li, 5 at.% of Cu and 30 at.% of Al and mounted in a thin-walled capillary. Intensity data were collected using an Xcalibur diffractometer from Oxford Diffraction, equipped with the Sapphire2 CCD detector and the ENHANCE X-ray source option. All observed reflections can be indexed based on a hexagonal cell, a = 4.935 (1) Å, c = 18.380 (4) Å without any additional extinction rules. A combined empirical absorption correction with frame scaling was applied, using the SCALE3 ABSPACK command in CrysAlis RED (Oxford Diffraction, 2005).

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. The structure has been solved by direct methods and refined using the SHELX97 program package (Sheldrick, 1997). An initial parameter set was obtained from automatic interpretations of direct methods using SHELXS97, and this structure model was further refined until convergence using SHELXL97.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
Cu10.66670.33330.17727 (14)0.0097 (9)*0.153 (7)
Al10.66670.33330.17727 (14)0.0097 (9)*0.847 (7)
Cu20.00000.00000.00000.0124 (12)*0.272 (10)
Al20.00000.00000.00000.0124 (12)*0.728 (10)
Cu30.16729 (10)0.33457 (19)0.11801 (4)0.0121 (3)
Li10.00000.00000.25000.004 (3)*
Li20.33330.66670.25000.004 (3)*
Li30.66670.33330.0263 (10)0.004 (3)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu30.0078 (4)0.0068 (5)0.0214 (5)0.0034 (2)0.00053 (19)0.0011 (4)
Geometric parameters (Å, º) top
Cu1—Al1i2.674 (5)Al2—Li3xiii2.890 (3)
Cu1—Cu1i2.674 (5)Al2—Li3viii2.890 (3)
Cu1—Cu3ii2.6973 (12)Al2—Li32.890 (3)
Cu1—Cu3iii2.6973 (12)Al2—Li3xiv2.890 (3)
Cu1—Cu3iv2.6973 (12)Al2—Li3xv2.890 (3)
Cu1—Cu3v2.6973 (12)Cu3—Cu3vi2.4584 (15)
Cu1—Cu32.6973 (12)Cu3—Cu3xvi2.4584 (15)
Cu1—Cu3vi2.6973 (12)Cu3—Cu3x2.4767 (15)
Cu1—Li32.775 (18)Cu3—Cu3ii2.4767 (15)
Cu1—Li2iv3.1473 (12)Cu3—Al1xiii2.6973 (12)
Cu1—Li2vii3.1473 (12)Cu3—Cu1xiii2.6973 (12)
Cu1—Li1iv3.1473 (12)Cu3—Li22.8107 (9)
Al1—Al1i2.674 (5)Cu3—Li12.8160 (9)
Al1—Cu1i2.674 (5)Li1—Cu3i2.8160 (9)
Al1—Cu3ii2.6973 (12)Li1—Cu3x2.8160 (9)
Al1—Cu3iii2.6973 (12)Li1—Cu3xvii2.8160 (9)
Al1—Cu3iv2.6973 (12)Li1—Cu3ii2.8160 (9)
Al1—Cu3v2.6973 (12)Li1—Cu3xviii2.8160 (9)
Al1—Cu32.6973 (12)Li1—Li2vii2.8493 (6)
Al1—Cu3vi2.6973 (12)Li1—Li2xv2.8493 (6)
Al1—Li32.775 (18)Li1—Li22.8493 (6)
Al1—Li2iv3.1473 (12)Li1—Cu1xiii3.1473 (12)
Al1—Li2vii3.1473 (12)Li1—Al1xiii3.1473 (12)
Al1—Li1iv3.1473 (12)Li1—Cu1xv3.1473 (12)
Cu2—Cu32.5980 (8)Li2—Cu3xix2.8107 (9)
Cu2—Cu3viii2.5980 (8)Li2—Cu3xx2.8107 (9)
Cu2—Cu3ix2.5980 (8)Li2—Cu3xvi2.8107 (9)
Cu2—Cu3ii2.5980 (8)Li2—Cu3i2.8107 (9)
Cu2—Cu3x2.5980 (8)Li2—Cu3vi2.8107 (9)
Cu2—Cu3xi2.5980 (8)Li2—Li1xxi2.8493 (6)
Cu2—Li3xii2.890 (3)Li2—Li1xxii2.8493 (6)
Cu2—Li3xiii2.890 (3)Li2—Cu1xiii3.1473 (12)
Cu2—Li3viii2.890 (3)Li2—Al1xiii3.1473 (12)
Cu2—Li32.890 (3)Li2—Cu1xxiii3.1473 (12)
Cu2—Li3xiv2.890 (3)Li3—Al2iv2.890 (3)
Cu2—Li3xv2.890 (3)Li3—Cu2iv2.890 (3)
Al2—Cu32.5980 (8)Li3—Al2xxii2.890 (3)
Al2—Cu3viii2.5980 (8)Li3—Cu2xxii2.890 (3)
Al2—Cu3ix2.5980 (8)Li3—Cu3v2.988 (10)
Al2—Cu3ii2.5980 (8)Li3—Cu3iv2.988 (10)
Al2—Cu3x2.5980 (8)Li3—Cu3iii2.988 (10)
Al2—Cu3xi2.5980 (8)Li3—Cu3ii2.988 (10)
Al2—Li3xii2.890 (3)
Al1i—Cu1—Cu3ii113.82 (5)Cu3vi—Cu3—Cu3xvi60.0
Cu1i—Cu1—Cu3ii113.82 (5)Cu3vi—Cu3—Cu3x180.00 (4)
Al1i—Cu1—Cu3iii113.82 (5)Cu3xvi—Cu3—Cu3x120.0
Cu1i—Cu1—Cu3iii113.82 (5)Cu3vi—Cu3—Cu3ii120.0
Cu3ii—Cu1—Cu3iii54.22 (4)Cu3xvi—Cu3—Cu3ii180.0
Al1i—Cu1—Cu3iv113.82 (5)Cu3x—Cu3—Cu3ii60.0
Cu1i—Cu1—Cu3iv113.82 (5)Cu3vi—Cu3—Al2118.468 (16)
Cu3ii—Cu1—Cu3iv104.80 (6)Cu3xvi—Cu3—Al2118.468 (16)
Cu3iii—Cu1—Cu3iv54.66 (4)Cu3x—Cu3—Al261.532 (16)
Al1i—Cu1—Cu3v113.82 (5)Cu3ii—Cu3—Al261.532 (16)
Cu1i—Cu1—Cu3v113.82 (5)Cu3vi—Cu3—Cu2118.468 (16)
Cu3ii—Cu1—Cu3v132.36 (10)Cu3xvi—Cu3—Cu2118.468 (16)
Cu3iii—Cu1—Cu3v104.80 (6)Cu3x—Cu3—Cu261.532 (16)
Cu3iv—Cu1—Cu3v54.22 (4)Cu3ii—Cu3—Cu261.532 (16)
Al1i—Cu1—Cu3113.82 (5)Cu3vi—Cu3—Al1xiii117.33 (2)
Cu1i—Cu1—Cu3113.82 (5)Cu3xvi—Cu3—Al1xiii62.89 (2)
Cu3ii—Cu1—Cu354.66 (4)Cu3x—Cu3—Al1xiii62.67 (2)
Cu3iii—Cu1—Cu3104.80 (6)Cu3ii—Cu3—Al1xiii117.11 (2)
Cu3iv—Cu1—Cu3132.36 (10)Al2—Cu3—Al1xiii109.64 (4)
Cu3v—Cu1—Cu3104.80 (6)Cu2—Cu3—Al1xiii109.64 (4)
Al1i—Cu1—Cu3vi113.82 (5)Cu3vi—Cu3—Cu1xiii117.33 (2)
Cu1i—Cu1—Cu3vi113.82 (5)Cu3xvi—Cu3—Cu1xiii62.89 (2)
Cu3ii—Cu1—Cu3vi104.80 (6)Cu3x—Cu3—Cu1xiii62.67 (2)
Cu3iii—Cu1—Cu3vi132.36 (10)Cu3ii—Cu3—Cu1xiii117.11 (2)
Cu3iv—Cu1—Cu3vi104.80 (6)Al2—Cu3—Cu1xiii109.64 (4)
Cu3v—Cu1—Cu3vi54.66 (4)Cu2—Cu3—Cu1xiii109.64 (4)
Cu3—Cu1—Cu3vi54.22 (4)Al1xiii—Cu3—Cu1xiii0.00 (10)
Al1i—Cu1—Li3180.000 (1)Cu3vi—Cu3—Al162.89 (2)
Cu1i—Cu1—Li3180.000 (1)Cu3xvi—Cu3—Al1117.33 (2)
Cu3ii—Cu1—Li366.18 (5)Cu3x—Cu3—Al1117.11 (2)
Cu3iii—Cu1—Li366.18 (5)Cu3ii—Cu3—Al162.67 (2)
Cu3iv—Cu1—Li366.18 (5)Al2—Cu3—Al1109.64 (4)
Cu3v—Cu1—Li366.18 (5)Cu2—Cu3—Al1109.64 (4)
Cu3—Cu1—Li366.18 (5)Al1xiii—Cu3—Al1132.36 (10)
Cu3vi—Cu1—Li366.18 (5)Cu1xiii—Cu3—Al1132.36 (10)
Al1i—Cu1—Li2iv64.87 (4)Cu3vi—Cu3—Cu162.89 (2)
Cu1i—Cu1—Li2iv64.87 (4)Cu3xvi—Cu3—Cu1117.33 (2)
Cu3ii—Cu1—Li2iv152.609 (18)Cu3x—Cu3—Cu1117.11 (2)
Cu3iii—Cu1—Li2iv99.979 (18)Cu3ii—Cu3—Cu162.67 (2)
Cu3iv—Cu1—Li2iv56.86 (2)Al2—Cu3—Cu1109.64 (4)
Cu3v—Cu1—Li2iv56.86 (2)Cu2—Cu3—Cu1109.64 (4)
Cu3—Cu1—Li2iv152.609 (18)Al1xiii—Cu3—Cu1132.36 (10)
Cu3vi—Cu1—Li2iv99.979 (18)Cu1xiii—Cu3—Cu1132.36 (10)
Li3—Cu1—Li2iv115.13 (4)Al1—Cu3—Cu10.00 (10)
Al1i—Cu1—Li2vii64.87 (4)Cu3vi—Cu3—Li264.066 (15)
Cu1i—Cu1—Li2vii64.87 (4)Cu3xvi—Cu3—Li264.066 (15)
Cu3ii—Cu1—Li2vii56.86 (2)Cu3x—Cu3—Li2115.934 (15)
Cu3iii—Cu1—Li2vii56.86 (2)Cu3ii—Cu3—Li2115.934 (15)
Cu3iv—Cu1—Li2vii99.979 (18)Al2—Cu3—Li2176.94 (3)
Cu3v—Cu1—Li2vii152.609 (18)Cu2—Cu3—Li2176.94 (3)
Cu3—Cu1—Li2vii99.979 (18)Al1xiii—Cu3—Li269.66 (5)
Cu3vi—Cu1—Li2vii152.609 (18)Cu1xiii—Cu3—Li269.66 (5)
Li3—Cu1—Li2vii115.13 (4)Al1—Cu3—Li269.66 (5)
Li2iv—Cu1—Li2vii103.26 (5)Cu1—Cu3—Li269.66 (5)
Al1i—Cu1—Li1iv64.87 (4)Cu3vi—Cu3—Li1116.088 (15)
Cu1i—Cu1—Li1iv64.87 (4)Cu3xvi—Cu3—Li1116.088 (15)
Cu3ii—Cu1—Li1iv99.773 (18)Cu3x—Cu3—Li163.912 (15)
Cu3iii—Cu1—Li1iv56.99 (2)Cu3ii—Cu3—Li163.912 (15)
Cu3iv—Cu1—Li1iv56.99 (2)Al2—Cu3—Li1116.09 (3)
Cu3v—Cu1—Li1iv99.773 (18)Cu2—Cu3—Li1116.09 (3)
Cu3—Cu1—Li1iv152.831 (18)Al1xiii—Cu3—Li169.58 (5)
Cu3vi—Cu1—Li1iv152.831 (18)Cu1xiii—Cu3—Li169.58 (5)
Li3—Cu1—Li1iv115.13 (4)Al1—Cu3—Li169.58 (5)
Li2iv—Cu1—Li1iv53.83 (2)Cu1—Cu3—Li169.58 (5)
Li2vii—Cu1—Li1iv53.83 (2)Li2—Cu3—Li160.85 (2)
Al1i—Al1—Cu1i0.0Cu3i—Li1—Cu3x150.584 (16)
Al1i—Al1—Cu3ii113.82 (5)Cu3i—Li1—Cu3xvii52.18 (3)
Cu1i—Al1—Cu3ii113.82 (5)Cu3x—Li1—Cu3xvii150.584 (16)
Al1i—Al1—Cu3iii113.82 (5)Cu3i—Li1—Cu3ii150.584 (16)
Cu1i—Al1—Cu3iii113.82 (5)Cu3x—Li1—Cu3ii52.18 (3)
Cu3ii—Al1—Cu3iii54.22 (4)Cu3xvii—Li1—Cu3ii118.97 (4)
Al1i—Al1—Cu3iv113.82 (5)Cu3i—Li1—Cu3118.97 (4)
Cu1i—Al1—Cu3iv113.82 (5)Cu3x—Li1—Cu352.18 (3)
Cu3ii—Al1—Cu3iv104.80 (6)Cu3xvii—Li1—Cu3150.584 (16)
Cu3iii—Al1—Cu3iv54.66 (4)Cu3ii—Li1—Cu352.18 (3)
Al1i—Al1—Cu3v113.82 (5)Cu3i—Li1—Cu3xviii52.18 (3)
Cu1i—Al1—Cu3v113.82 (5)Cu3x—Li1—Cu3xviii118.97 (4)
Cu3ii—Al1—Cu3v132.36 (10)Cu3xvii—Li1—Cu3xviii52.18 (3)
Cu3iii—Al1—Cu3v104.80 (6)Cu3ii—Li1—Cu3xviii150.584 (16)
Cu3iv—Al1—Cu3v54.22 (4)Cu3—Li1—Cu3xviii150.584 (16)
Al1i—Al1—Cu3113.82 (5)Cu3i—Li1—Li2vii104.708 (8)
Cu1i—Al1—Cu3113.82 (5)Cu3x—Li1—Li2vii104.708 (8)
Cu3ii—Al1—Cu354.66 (4)Cu3xvii—Li1—Li2vii59.484 (18)
Cu3iii—Al1—Cu3104.80 (6)Cu3ii—Li1—Li2vii59.484 (18)
Cu3iv—Al1—Cu3132.36 (10)Cu3—Li1—Li2vii104.708 (8)
Cu3v—Al1—Cu3104.80 (6)Cu3xviii—Li1—Li2vii104.708 (8)
Al1i—Al1—Cu3vi113.82 (5)Cu3i—Li1—Li2xv104.708 (8)
Cu1i—Al1—Cu3vi113.82 (5)Cu3x—Li1—Li2xv59.484 (18)
Cu3ii—Al1—Cu3vi104.80 (6)Cu3xvii—Li1—Li2xv104.708 (8)
Cu3iii—Al1—Cu3vi132.36 (10)Cu3ii—Li1—Li2xv104.708 (8)
Cu3iv—Al1—Cu3vi104.80 (6)Cu3—Li1—Li2xv104.708 (8)
Cu3v—Al1—Cu3vi54.66 (4)Cu3xviii—Li1—Li2xv59.484 (18)
Cu3—Al1—Cu3vi54.22 (4)Li2vii—Li1—Li2xv120.0
Al1i—Al1—Li3180.000 (1)Cu3i—Li1—Li259.484 (18)
Cu1i—Al1—Li3180.000 (1)Cu3x—Li1—Li2104.708 (8)
Cu3ii—Al1—Li366.18 (5)Cu3xvii—Li1—Li2104.708 (8)
Cu3iii—Al1—Li366.18 (5)Cu3ii—Li1—Li2104.708 (8)
Cu3iv—Al1—Li366.18 (5)Cu3—Li1—Li259.484 (18)
Cu3v—Al1—Li366.18 (5)Cu3xviii—Li1—Li2104.708 (8)
Cu3—Al1—Li366.18 (5)Li2vii—Li1—Li2120.0
Cu3vi—Al1—Li366.18 (5)Li2xv—Li1—Li2120.0
Al1i—Al1—Li2iv64.87 (4)Cu3i—Li1—Cu1xiii97.82 (4)
Cu1i—Al1—Li2iv64.87 (4)Cu3x—Li1—Cu1xiii53.43 (4)
Cu3ii—Al1—Li2iv152.609 (18)Cu3xvii—Li1—Cu1xiii145.65 (5)
Cu3iii—Al1—Li2iv99.979 (18)Cu3ii—Li1—Cu1xiii95.38 (5)
Cu3iv—Al1—Li2iv56.86 (2)Cu3—Li1—Cu1xiii53.43 (4)
Cu3v—Al1—Li2iv56.86 (2)Cu3xviii—Li1—Cu1xiii97.82 (4)
Cu3—Al1—Li2iv152.609 (18)Li2vii—Li1—Cu1xiii154.87 (4)
Cu3vi—Al1—Li2iv99.979 (18)Li2xv—Li1—Cu1xiii63.086 (10)
Li3—Al1—Li2iv115.13 (4)Li2—Li1—Cu1xiii63.086 (10)
Al1i—Al1—Li2vii64.87 (4)Cu3i—Li1—Al1xiii97.82 (4)
Cu1i—Al1—Li2vii64.87 (4)Cu3x—Li1—Al1xiii53.43 (4)
Cu3ii—Al1—Li2vii56.86 (2)Cu3xvii—Li1—Al1xiii145.65 (5)
Cu3iii—Al1—Li2vii56.86 (2)Cu3ii—Li1—Al1xiii95.38 (5)
Cu3iv—Al1—Li2vii99.979 (18)Cu3—Li1—Al1xiii53.43 (4)
Cu3v—Al1—Li2vii152.609 (18)Cu3xviii—Li1—Al1xiii97.82 (4)
Cu3—Al1—Li2vii99.979 (18)Li2vii—Li1—Al1xiii154.87 (4)
Cu3vi—Al1—Li2vii152.609 (18)Li2xv—Li1—Al1xiii63.086 (10)
Li3—Al1—Li2vii115.13 (4)Li2—Li1—Al1xiii63.086 (10)
Li2iv—Al1—Li2vii103.26 (5)Cu1xiii—Li1—Al1xiii0.00 (8)
Al1i—Al1—Li1iv64.87 (4)Cu3i—Li1—Cu1xv145.65 (5)
Cu1i—Al1—Li1iv64.87 (4)Cu3x—Li1—Cu1xv53.43 (4)
Cu3ii—Al1—Li1iv99.773 (18)Cu3xvii—Li1—Cu1xv97.82 (4)
Cu3iii—Al1—Li1iv56.99 (2)Cu3ii—Li1—Cu1xv53.43 (4)
Cu3iv—Al1—Li1iv56.99 (2)Cu3—Li1—Cu1xv95.38 (5)
Cu3v—Al1—Li1iv99.773 (18)Cu3xviii—Li1—Cu1xv97.82 (4)
Cu3—Al1—Li1iv152.831 (18)Li2vii—Li1—Cu1xv63.086 (10)
Cu3vi—Al1—Li1iv152.831 (18)Li2xv—Li1—Cu1xv63.086 (10)
Li3—Al1—Li1iv115.13 (4)Li2—Li1—Cu1xv154.87 (4)
Li2iv—Al1—Li1iv53.83 (2)Cu1xiii—Li1—Cu1xv103.26 (5)
Li2vii—Al1—Li1iv53.83 (2)Al1xiii—Li1—Cu1xv103.26 (5)
Cu3—Cu2—Cu3viii180.00 (4)Cu3xix—Li2—Cu3xx51.87 (3)
Cu3—Cu2—Cu3ix123.06 (3)Cu3xix—Li2—Cu3xvi150.750 (16)
Cu3viii—Cu2—Cu3ix56.94 (3)Cu3xx—Li2—Cu3xvi119.34 (4)
Cu3—Cu2—Cu3ii56.94 (3)Cu3xix—Li2—Cu3150.750 (16)
Cu3viii—Cu2—Cu3ii123.06 (3)Cu3xx—Li2—Cu3150.750 (16)
Cu3ix—Cu2—Cu3ii180.000 (18)Cu3xvi—Li2—Cu351.87 (3)
Cu3—Cu2—Cu3x56.94 (3)Cu3xix—Li2—Cu3i51.87 (3)
Cu3viii—Cu2—Cu3x123.06 (3)Cu3xx—Li2—Cu3i51.87 (3)
Cu3ix—Cu2—Cu3x123.06 (3)Cu3xvi—Li2—Cu3i150.750 (16)
Cu3ii—Cu2—Cu3x56.94 (3)Cu3—Li2—Cu3i119.34 (4)
Cu3—Cu2—Cu3xi123.06 (3)Cu3xix—Li2—Cu3vi119.34 (4)
Cu3viii—Cu2—Cu3xi56.94 (3)Cu3xx—Li2—Cu3vi150.750 (16)
Cu3ix—Cu2—Cu3xi56.94 (3)Cu3xvi—Li2—Cu3vi51.87 (3)
Cu3ii—Cu2—Cu3xi123.06 (3)Cu3—Li2—Cu3vi51.87 (3)
Cu3x—Cu2—Cu3xi180.00 (4)Cu3i—Li2—Cu3vi150.750 (16)
Cu3—Cu2—Li3xii114.3 (3)Cu3xix—Li2—Li1xxi104.625 (8)
Cu3viii—Cu2—Li3xii65.7 (3)Cu3xx—Li2—Li1xxi59.670 (18)
Cu3ix—Cu2—Li3xii113.8 (3)Cu3xvi—Li2—Li1xxi59.670 (18)
Cu3ii—Cu2—Li3xii66.2 (3)Cu3—Li2—Li1xxi104.625 (8)
Cu3x—Cu2—Li3xii114.3 (3)Cu3i—Li2—Li1xxi104.625 (8)
Cu3xi—Cu2—Li3xii65.7 (3)Cu3vi—Li2—Li1xxi104.625 (8)
Cu3—Cu2—Li3xiii65.7 (3)Cu3xix—Li2—Li1xxii59.670 (18)
Cu3viii—Cu2—Li3xiii114.3 (3)Cu3xx—Li2—Li1xxii104.625 (8)
Cu3ix—Cu2—Li3xiii66.2 (3)Cu3xvi—Li2—Li1xxii104.625 (8)
Cu3ii—Cu2—Li3xiii113.8 (3)Cu3—Li2—Li1xxii104.625 (8)
Cu3x—Cu2—Li3xiii65.7 (3)Cu3i—Li2—Li1xxii104.625 (8)
Cu3xi—Cu2—Li3xiii114.3 (3)Cu3vi—Li2—Li1xxii59.670 (18)
Li3xii—Cu2—Li3xiii180.0Li1xxi—Li2—Li1xxii120.0
Cu3—Cu2—Li3viii114.3 (3)Cu3xix—Li2—Li1104.625 (8)
Cu3viii—Cu2—Li3viii65.7 (3)Cu3xx—Li2—Li1104.625 (8)
Cu3ix—Cu2—Li3viii65.7 (3)Cu3xvi—Li2—Li1104.625 (8)
Cu3ii—Cu2—Li3viii114.3 (3)Cu3—Li2—Li159.670 (18)
Cu3x—Cu2—Li3viii66.2 (3)Cu3i—Li2—Li159.670 (18)
Cu3xi—Cu2—Li3viii113.8 (3)Cu3vi—Li2—Li1104.625 (8)
Li3xii—Cu2—Li3viii117.26 (19)Li1xxi—Li2—Li1120.0
Li3xiii—Cu2—Li3viii62.74 (19)Li1xxii—Li2—Li1120.0
Cu3—Cu2—Li365.7 (3)Cu3xix—Li2—Cu1xiii145.46 (5)
Cu3viii—Cu2—Li3114.3 (3)Cu3xx—Li2—Cu1xiii97.93 (4)
Cu3ix—Cu2—Li3114.3 (3)Cu3xvi—Li2—Cu1xiii53.47 (4)
Cu3ii—Cu2—Li365.7 (3)Cu3—Li2—Cu1xiii53.47 (4)
Cu3x—Cu2—Li3113.8 (3)Cu3i—Li2—Cu1xiii97.93 (4)
Cu3xi—Cu2—Li366.2 (3)Cu3vi—Li2—Cu1xiii95.20 (5)
Li3xii—Cu2—Li362.74 (19)Li1xxi—Li2—Cu1xiii63.086 (10)
Li3xiii—Cu2—Li3117.26 (19)Li1xxii—Li2—Cu1xiii154.87 (4)
Li3viii—Cu2—Li3180.0Li1—Li2—Cu1xiii63.086 (10)
Cu3—Cu2—Li3xiv66.2 (3)Cu3xix—Li2—Al1xiii145.46 (5)
Cu3viii—Cu2—Li3xiv113.8 (3)Cu3xx—Li2—Al1xiii97.93 (4)
Cu3ix—Cu2—Li3xiv65.7 (3)Cu3xvi—Li2—Al1xiii53.47 (4)
Cu3ii—Cu2—Li3xiv114.3 (3)Cu3—Li2—Al1xiii53.47 (4)
Cu3x—Cu2—Li3xiv114.3 (3)Cu3i—Li2—Al1xiii97.93 (4)
Cu3xi—Cu2—Li3xiv65.7 (3)Cu3vi—Li2—Al1xiii95.20 (5)
Li3xii—Cu2—Li3xiv117.26 (19)Li1xxi—Li2—Al1xiii63.086 (10)
Li3xiii—Cu2—Li3xiv62.74 (19)Li1xxii—Li2—Al1xiii154.87 (4)
Li3viii—Cu2—Li3xiv117.26 (19)Li1—Li2—Al1xiii63.086 (10)
Li3—Cu2—Li3xiv62.74 (19)Cu1xiii—Li2—Al1xiii0.0
Cu3—Cu2—Li3xv113.8 (3)Cu3xix—Li2—Cu1xxiii53.47 (4)
Cu3viii—Cu2—Li3xv66.2 (3)Cu3xx—Li2—Cu1xxiii53.47 (4)
Cu3ix—Cu2—Li3xv114.3 (3)Cu3xvi—Li2—Cu1xxiii97.93 (4)
Cu3ii—Cu2—Li3xv65.7 (3)Cu3—Li2—Cu1xxiii145.46 (5)
Cu3x—Cu2—Li3xv65.7 (3)Cu3i—Li2—Cu1xxiii95.20 (5)
Cu3xi—Cu2—Li3xv114.3 (3)Cu3vi—Li2—Cu1xxiii97.93 (4)
Li3xii—Cu2—Li3xv62.74 (19)Li1xxi—Li2—Cu1xxiii63.086 (10)
Li3xiii—Cu2—Li3xv117.26 (19)Li1xxii—Li2—Cu1xxiii63.086 (10)
Li3viii—Cu2—Li3xv62.74 (19)Li1—Li2—Cu1xxiii154.87 (4)
Li3—Cu2—Li3xv117.26 (19)Cu1xiii—Li2—Cu1xxiii126.17 (2)
Li3xiv—Cu2—Li3xv180.0Al1xiii—Li2—Cu1xxiii126.17 (2)
Cu3—Al2—Cu3viii180.00 (4)Al1—Li3—Cu10.0
Cu3—Al2—Cu3ix123.06 (3)Al1—Li3—Al2iv99.6 (3)
Cu3viii—Al2—Cu3ix56.94 (3)Cu1—Li3—Al2iv99.6 (3)
Cu3—Al2—Cu3ii56.94 (3)Al1—Li3—Cu2iv99.6 (3)
Cu3viii—Al2—Cu3ii123.06 (3)Cu1—Li3—Cu2iv99.6 (3)
Cu3ix—Al2—Cu3ii180.000 (18)Al2iv—Li3—Cu2iv0.0
Cu3—Al2—Cu3x56.94 (3)Al1—Li3—Cu299.6 (3)
Cu3viii—Al2—Cu3x123.06 (3)Cu1—Li3—Cu299.6 (3)
Cu3ix—Al2—Cu3x123.06 (3)Al2iv—Li3—Cu2117.26 (19)
Cu3ii—Al2—Cu3x56.94 (3)Cu2iv—Li3—Cu2117.26 (19)
Cu3—Al2—Cu3xi123.06 (3)Al1—Li3—Al299.6 (3)
Cu3viii—Al2—Cu3xi56.94 (3)Cu1—Li3—Al299.6 (3)
Cu3ix—Al2—Cu3xi56.94 (3)Al2iv—Li3—Al2117.26 (19)
Cu3ii—Al2—Cu3xi123.06 (3)Cu2iv—Li3—Al2117.26 (19)
Cu3x—Al2—Cu3xi180.00 (4)Cu2—Li3—Al20.0
Cu3—Al2—Li3xii114.3 (3)Al1—Li3—Al2xxii99.6 (3)
Cu3viii—Al2—Li3xii65.7 (3)Cu1—Li3—Al2xxii99.6 (3)
Cu3ix—Al2—Li3xii113.8 (3)Al2iv—Li3—Al2xxii117.26 (19)
Cu3ii—Al2—Li3xii66.2 (3)Cu2iv—Li3—Al2xxii117.26 (19)
Cu3x—Al2—Li3xii114.3 (3)Cu2—Li3—Al2xxii117.26 (19)
Cu3xi—Al2—Li3xii65.7 (3)Al2—Li3—Al2xxii117.26 (19)
Cu3—Al2—Li3xiii65.7 (3)Al1—Li3—Cu2xxii99.6 (3)
Cu3viii—Al2—Li3xiii114.3 (3)Cu1—Li3—Cu2xxii99.6 (3)
Cu3ix—Al2—Li3xiii66.2 (3)Al2iv—Li3—Cu2xxii117.26 (19)
Cu3ii—Al2—Li3xiii113.8 (3)Cu2iv—Li3—Cu2xxii117.26 (19)
Cu3x—Al2—Li3xiii65.7 (3)Cu2—Li3—Cu2xxii117.26 (19)
Cu3xi—Al2—Li3xiii114.3 (3)Al2—Li3—Cu2xxii117.26 (19)
Li3xii—Al2—Li3xiii180.0Al2xxii—Li3—Cu2xxii0.0
Cu3—Al2—Li3viii114.3 (3)Al1—Li3—Cu3v55.7 (3)
Cu3viii—Al2—Li3viii65.7 (3)Cu1—Li3—Cu3v55.7 (3)
Cu3ix—Al2—Li3viii65.7 (3)Al2iv—Li3—Cu3v95.32 (15)
Cu3ii—Al2—Li3viii114.3 (3)Cu2iv—Li3—Cu3v95.32 (15)
Cu3x—Al2—Li3viii66.2 (3)Cu2—Li3—Cu3v143.2 (4)
Cu3xi—Al2—Li3viii113.8 (3)Al2—Li3—Cu3v143.2 (4)
Li3xii—Al2—Li3viii117.26 (19)Al2xxii—Li3—Cu3v52.43 (8)
Li3xiii—Al2—Li3viii62.74 (19)Cu2xxii—Li3—Cu3v52.43 (8)
Cu3—Al2—Li365.7 (3)Al1—Li3—Cu3iv55.7 (3)
Cu3viii—Al2—Li3114.3 (3)Cu1—Li3—Cu3iv55.7 (3)
Cu3ix—Al2—Li3114.3 (3)Al2iv—Li3—Cu3iv52.43 (8)
Cu3ii—Al2—Li365.7 (3)Cu2iv—Li3—Cu3iv52.43 (8)
Cu3x—Al2—Li3113.8 (3)Cu2—Li3—Cu3iv143.2 (4)
Cu3xi—Al2—Li366.2 (3)Al2—Li3—Cu3iv143.2 (4)
Li3xii—Al2—Li362.74 (19)Al2xxii—Li3—Cu3iv95.32 (15)
Li3xiii—Al2—Li3117.26 (19)Cu2xxii—Li3—Cu3iv95.32 (15)
Li3viii—Al2—Li3180.0Cu3v—Li3—Cu3iv48.58 (17)
Cu3—Al2—Li3xiv66.2 (3)Al1—Li3—Cu3iii55.7 (3)
Cu3viii—Al2—Li3xiv113.8 (3)Cu1—Li3—Cu3iii55.7 (3)
Cu3ix—Al2—Li3xiv65.7 (3)Al2iv—Li3—Cu3iii52.43 (8)
Cu3ii—Al2—Li3xiv114.3 (3)Cu2iv—Li3—Cu3iii52.43 (8)
Cu3x—Al2—Li3xiv114.3 (3)Cu2—Li3—Cu3iii95.32 (15)
Cu3xi—Al2—Li3xiv65.7 (3)Al2—Li3—Cu3iii95.32 (15)
Li3xii—Al2—Li3xiv117.26 (19)Al2xxii—Li3—Cu3iii143.2 (4)
Li3xiii—Al2—Li3xiv62.74 (19)Cu2xxii—Li3—Cu3iii143.2 (4)
Li3viii—Al2—Li3xiv117.26 (19)Cu3v—Li3—Cu3iii91.3 (4)
Li3—Al2—Li3xiv62.74 (19)Cu3iv—Li3—Cu3iii48.97 (18)
Cu3—Al2—Li3xv113.8 (3)Al1—Li3—Cu3ii55.7 (3)
Cu3viii—Al2—Li3xv66.2 (3)Cu1—Li3—Cu3ii55.7 (3)
Cu3ix—Al2—Li3xv114.3 (3)Al2iv—Li3—Cu3ii95.32 (15)
Cu3ii—Al2—Li3xv65.7 (3)Cu2iv—Li3—Cu3ii95.32 (15)
Cu3x—Al2—Li3xv65.7 (3)Cu2—Li3—Cu3ii52.43 (8)
Cu3xi—Al2—Li3xv114.3 (3)Al2—Li3—Cu3ii52.43 (8)
Li3xii—Al2—Li3xv62.74 (19)Al2xxii—Li3—Cu3ii143.2 (4)
Li3xiii—Al2—Li3xv117.26 (19)Cu2xxii—Li3—Cu3ii143.2 (4)
Li3viii—Al2—Li3xv62.74 (19)Cu3v—Li3—Cu3ii111.3 (6)
Li3—Al2—Li3xv117.26 (19)Cu3iv—Li3—Cu3ii91.3 (4)
Li3xiv—Al2—Li3xv180.0Cu3iii—Li3—Cu3ii48.58 (17)
Symmetry codes: (i) x, y, z+1/2; (ii) x+y, x, z; (iii) y+1, xy, z; (iv) x+1, y, z; (v) x+y+1, x+1, z; (vi) y+1, xy+1, z; (vii) x, y1, z; (viii) x, y, z; (ix) xy, x, z; (x) y, xy, z; (xi) y, x+y, z; (xii) x+1, y, z; (xiii) x1, y, z; (xiv) x+1, y+1, z; (xv) x1, y1, z; (xvi) x+y, x+1, z; (xvii) x+y, x, z+1/2; (xviii) y, xy, z+1/2; (xix) y+1, xy+1, z+1/2; (xx) x+y, x+1, z+1/2; (xxi) x, y+1, z; (xxii) x+1, y+1, z; (xxiii) x, y+1, z+1/2.

Experimental details

Crystal data
Chemical formulaLi8Cu13.16Al4.84
Mr1022.27
Crystal system, space groupHexagonal, P63/mmc
Temperature (K)295
a, c (Å)4.9351 (10), 18.380 (4)
V3)387.68 (14)
Z1
Radiation typeMo Kα
µ (mm1)17.87
Crystal size (mm)0.09 × 0.05 × 0.01
Data collection
DiffractometerOxford Diffraction Xcalibur3 CCD
diffractometer
Absorption correctionEmpirical (using intensity measurements)
(CrysAlis RED; Oxford Diffraction, 2005)
Tmin, Tmax0.35, 0.83
No. of measured, independent and
observed [I > 2σ(I)] reflections
1046, 188, 133
Rint0.046
(sin θ/λ)max1)0.625
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.027, 0.058, 1.00
No. of reflections188
No. of parameters14
Δρmax, Δρmin (e Å3)0.88, 0.85

Computer programs: CrysAlis CCD (Oxford Diffraction, 2004), CrysAlis RED (Oxford Diffraction, 2005), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), DIAMOND (Brandenburg, 1999).

Selected bond lengths (Å) top
Al1—Al1i2.674 (5)Cu3—Cu3ii2.4584 (15)
Al1—Li32.775 (18)Cu3—Li22.8107 (9)
Al2—Cu32.5980 (8)Cu3—Li12.8160 (9)
Symmetry codes: (i) x, y, z+1/2; (ii) y+1, xy+1, z.
 

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