Li₁₂Cu_16+xAl_26-x (x = 3.2): a new inter­metallic structure type

The new ternary lithium copper aluminide, Li₁₂Cu_16+xAl_26-x (x = 3.2), dodeca­lithium nona­deca­copper tricosa­aluminide, crystallizes in a new structure type with space group P4/mbm. Among nine independent atomic positions, two Al (one of which is statistically disordered with Cu) and three Li atoms have point symmetry m.2m, two statistically disordered Al/Cu atoms are in m.. sites, one Al atom is in a 4/m.. site and one Cu atom occupies a general site. The framework of Li₁₂Cu_16+xAl_26-x consists of pseudo-Frank-Kasper polyhedra enclosing channels of hexa­gonal prisms occupied by Li atoms. The crystallochemical peculiarity of this new structure type is discussed in relation to the derivatives from Laves phases (LiCuAl₂ and Li₈Cu_12+xAl_6-x) and to the well known CaCu₅ structure.

S1. Comment

The Li–Cu–Al ternary system has been the subject of intense scientific scrutiny for many decades. The first report on the crystal structures of intermetallides existing in this system was made by Hardy & Silcock (1955–1956), but the majority of papers dedicated to the investigation of these compounds were published beginning in the late 1980s. Intermetallides in this system adopt highly symmetrical structures; Li₃CuAl₅ (Audier et al., 1988; Guryan et al., 1988), LiCu₄Al_7.5 (Schneider & von Heimendahl, 1973) and Li₃CuAl₆ (Dubost et al., 1986; Konno et al., 2002) belong to the cubic system, while LiCuAl₂ (Knowles & Stobbs, 1988; Van Smaalen et al., 1990) and Li₈Cu_12+xAl_6-x (Pavlyuk et al., 2008) are hexagonal. The family of quasicrystals of nominal composition close to Li₃CuAl₆, reviewed by Steurer & Deloudi (2008), has attracted the greatest interest among researchers.

Within the framework of our continuing studies of lithium aluminides, we report here the structure of the new compound, Li₁₂Cu_16+xAl_26-x (x = 3.2). To our knowledge, it is the first compound with tetragonal symmetry in the Li–Cu–Al system. Moreover this intermetallide crystallizes in a new structure type with the space group P4/mbm (No. 127), Pearson symbol tP54. The structure of Li₁₂Cu_16+xAl_26-x contains three Li, one Cu, two Al and three Al/Cu statistically mixed positions in the asymmetric unit. For simplicity hereinafter the last positions are designated as Al2, Al3 and Al6, because more Al than Cu is located on these sites. The clinographic projections of the unit cell and coordination polyhedra of atoms are shown in Fig. 1.

Atoms Li1 and Li2 occupy 4g and 4h Wyckoff sites and are surrounded by 15 neighbouring atoms in the form of tri-capped distorted icosahedra, [(Li1)Li₂Cu₄Al₄LiAl₄] and [(Li2)Li₃Cu₄Al₈]. The coordination around atom Li3 (4h site) consists of 14 atoms, resulting in a deformed icosahedron with two additional vertices [(Li3)LiAl₃Cu₄Al₆]. The bonding distances for the Li atoms cover the range 2.49 (5)–3.24 (2) Å. The coordination polyhedra around the Cu atoms (in the 16l position) are distorted icosahedra of composition [(Cu1)Al₂Cu₂Al₄Li₃Al] with distances to the nearest and farthest atoms of 2.453</span>(2) and 3.324 (1) Å. Atom Al5 (2a site) is surrounded by 20 adjacent atoms [(Al5)Al₁₂Cu₈] in the form of a pseudo-Frank–Kasper polyhedron. Atoms Al4 and Al6 (Wyckoff sites 4h and 8i, respectively) are characterized by irregular icosahedra with two extra vertices, [(Al4)LiAlCu₄Al₂Li₆] and [(Al6)Cu₂Al₂Cu₂Al₂Li₃AlLi₂], similar to the Li3 atoms. The coordination environments of atoms Al2 (4g) and Al3 (8j) are distorted (to different degrees) icosahedra, [(Al2)Cu₄Al₄Li₄] and [(Al3)Cu₄Al₂LiAl₂LiAl₂]. The shortest and longest contacts for Al atoms in the structure are 2.453 (2) and 3.324 (1) Å. The interatomic distances of the first coordination spheres of the atoms (Table 1) are in good agreement with the atomic radii of constituent elements (Emsley, 1991) and indicate metallic type bonding [the shortest Cu—Al distance, 2.453<span style=" font-weight:600;">(2) Å, is 90.6% of the sum of single-bond radii].

The pseudo-Frank–Kasper polyhedra around atom Al5 are slightly distorted compared with the analogous polyhedra in the CaCu₅ structure for the Ca atoms (Haucke, 1940). These 20-vertex polyhedra, sharing their rhombohedral faces in CaCu₅ and also in LiCuAl₂ (???van or Van Smaalen et al., 1990), form layers with rhombohedral and hexagonal channels between them, respectively. In Li₁₂Cu_16+xAl_26-x, the same constructive elements, namely pseudo-Frank–Kasper polyhedra connected along the [001] direction and hexagonal channels, can also be recognized (Fig. 2). For all the lithium-containing compounds in this family, including Li₈Cu_12+xAl_6-x (Pavlyuk et al., 2008), a special feature is that the Li atoms are located inside these hexagonal channels, which are connected by sharing edges and faces or byfaces only.

Related literature

For related literature, see: Audier et al. (1988); Dubost et al. (1986); Emsley (1991); Farrugia (1999); Guryan et al. (1988); Haucke (1940); Knowles & Stobbs (1988); Konno et al. (2002); Pauly (1966); Pauly et al. (1968); Pavlyuk et al. (2008); Schneider & von Heimendahl (1973); Steurer & Deloudi (2008); Van Smaalen, Meetsma, de Boer & Bronsveld (1990).

S2. Experimental

The title compound was prepared from elemental lithium (rod, 99.9 at.%), copper (ingots, 99.999 at.%) and aluminium (ingots, 99.999 at.%) in the slightly off-stoichiometric 25:35:40 ratio. The reaction mixture was sealed under argon atmosphere in a pure iron crucible and heated to 1370 K, with intensive shaking started approximately at 1270 K. After holding for 10 min at the maximum temperature, the product was cooled rapidly by removing the crucible from the furnace into ambient conditions. In the crushed sample, metallic dark-grey plate-shaped crystals were found using a conventional light microscope. On the basis of previous studies with successive detailed chemical analyses of similar systems (Pauly, 1966; Pauly et al., 1968), a loss of Li up to 1 at.% in nominal composition during sample preparation in hermetically closed crucibles can be expected. A single crystal was protected from air during X-ray data collection in a sealed thin-walled glass capillary (Heidelberg, No. 10).

S3. Refinement

A statistical test of the distribution of the E values using the program E-STATS from the WinGX system (Farrugia, 1999) suggested with a probability of 60.9% that the structure is centrosymmetric. The analysis of systematic extinctions yielded the space group P4/mbm (No. 127), which was confirmed by the following structure refinement. The structure was solved after the empirical absorption correction. In the first stage of the refinement, the positions of the Cu and Al atoms were obtained correctly by direct methods. The remaining Li atoms were located in subsequent difference Fourier syntheses. The Al2, Al3 and Al6 positions (Wyckoff sites 4g, 8j and 8i, respectively) showed displacement parameters considerably smaller than those of other Al sites, suggesting that these positions are partially occupied by the heavier atom Cu. The attempts to refine all atoms, except for lithium, with anisotropic displacement parameters and Al/Cu statistical distribution for three sites failed because of a very small content of copper in the Al6 site. Assuming this position to be occupied only by aluminium led to unreasonable displacement parameters. The Al:Cu ratio of the Al6 site was varied with fixed displacement parameters and eventually was fixed at 95:5 on the basis of R-factor values. In the final refinement cycles, isotropic and common isotropic displacement parameters for the Al6 position and all Li sites, respectively, were refined. All other atoms were successfully refined with anisotropic displacement parameters without any constraints. The maximum and minimum electron-density features in the final difference map are 1.37 and 0.90 Å from the Cu1 site, respectively.

Computing details

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, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. The clinographic projection of the Li12Cu16+xAl26-x unit-cell contents and coordination polyhedra of atoms.
	Fig. 2. The relationship between the Li12Cu16+xAl26-x, Li8Cu12+xAl6-x, LiCuAl2 and CaCu5 structures.

dodecalithium nonadecacopper tricosaaluminide

Crystal data

Li12Cu19.21Al22.84	Dx = 3.971 Mg m^−3
Mr = 1920.43	Mo Kα radiation, λ = 0.71073 Å
Tetragonal, P4/mbm	Cell parameters from 281 reflections
Hall symbol: -P 4 2ab	θ = 3.2–26.4°
a = 12.696 (2) Å	µ = 13.05 mm^−1
c = 4.982 (1) Å	T = 295 K
V = 803.0 (2) Å^3	Prism, metallic dark grey
Z = 1	0.1 × 0.08 × 0.04 mm
F(000) = 890.1

Data collection

Oxford Diffraction Xcalibur3 CCD diffractometer	490 independent reflections
Radiation source: fine-focus sealed tube	281 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.091
ω scans	θmax = 26.4°, θmin = 3.2°
Absorption correction: empirical (using intensity measurements) (CrysAlis RED; Oxford Diffraction, 2005)	h = −15→15
Tmin = 0.29, Tmax = 0.60	k = −15→12
2572 measured reflections	l = −2→6

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)] = 0.049	w = 1/[σ^2(Fo^2) + (0.0336P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.098	(Δ/σ)max < 0.001
S = 0.99	Δρmax = 0.98 e Å^−3
490 reflections	Δρmin = −1.03 e Å^−3
36 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.0005 (1)

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	Occ. (<1)
Cu1	0.24182 (10)	0.02248 (9)	0.2491 (4)	0.0115 (4)
Cu2	0.3609 (3)	0.1391 (3)	0.0000	0.0100 (18)	0.253 (9)
Al2	0.3609 (3)	0.1391 (3)	0.0000	0.0100 (18)	0.75
Cu3	0.0932 (3)	0.1173 (3)	0.5000	0.0127 (14)	0.225 (7)
Al3	0.0932 (3)	0.1173 (3)	0.5000	0.0127 (14)	0.78
Al4	0.4269 (4)	0.0731 (4)	0.5000	0.0116 (17)
Al5	0.0000	0.0000	0.0000	0.022 (3)
Al6	0.1535 (3)	0.1950 (4)	0.0000	0.0136 (12)*	0.95
Cu6	0.1535 (3)	0.1950 (4)	0.0000	0.0136 (12)*	0.05
Li1	0.086 (2)	0.414 (2)	0.0000	0.009 (4)*
Li2	0.142 (2)	0.358 (2)	0.5000	0.009 (4)*
Li3	0.2807 (19)	0.2193 (19)	0.5000	0.009 (4)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0131 (7)	0.0123 (7)	0.0091 (6)	−0.0028 (5)	0.0013 (7)	−0.0016 (10)
Cu2	0.012 (2)	0.012 (2)	0.006 (3)	−0.005 (2)	0.000	0.000
Al2	0.012 (2)	0.012 (2)	0.006 (3)	−0.005 (2)	0.000	0.000
Cu3	0.012 (2)	0.013 (2)	0.013 (2)	0.0037 (16)	0.000	0.000
Al3	0.012 (2)	0.013 (2)	0.013 (2)	0.0037 (16)	0.000	0.000
Al4	0.010 (2)	0.010 (2)	0.015 (4)	0.000 (3)	0.000	0.000
Al5	0.012 (3)	0.012 (3)	0.043 (7)	0.000	0.000	0.000

Geometric parameters (Å, º)

Cu1—Al2	2.4532 (15)	Al6—Cu1^i	2.755 (4)
Cu1—Cu1^i	2.482 (4)	Al6—Al3^vii	2.786 (3)
Cu1—Al3^ii	2.494 (3)	Al6—Cu3^vii	2.786 (3)
Cu1—Cu3^ii	2.494 (3)	Al6—Li1	2.92 (3)
Cu1—Cu1^iii	2.500 (4)	Al6—Li3	2.985 (11)
Cu1—Cu3	2.564 (3)	Al6—Li3^vii	2.985 (11)
Cu1—Cu6^iv	2.624 (4)	Al6—Li2	3.243 (18)
Cu1—Al6^iv	2.624 (4)	Al6—Li2^vii	3.243 (18)
Cu1—Al4	2.738 (3)	Li1—Li2^vii	2.688 (18)
Cu1—Al6	2.755 (4)	Li1—Li2	2.688 (18)
Cu1—Li3	2.837 (17)	Li1—Cu1^xv	2.87 (2)
Cu1—Li2^ii	2.85 (2)	Li1—Cu1^ix	2.87 (2)
Cu1—Li1^iv	2.87 (2)	Li1—Cu1^xvi	2.87 (2)
Cu2—Cu1^v	2.4532 (15)	Li1—Cu1^xvii	2.87 (2)
Cu2—Cu1^vi	2.4532 (15)	Li1—Cu6^v	2.92 (3)
Cu2—Cu1^i	2.4532 (15)	Li1—Al6^v	2.92 (3)
Cu2—Cu6^v	2.726 (6)	Li1—Cu2^ix	2.93 (2)
Cu2—Al6^v	2.726 (6)	Li1—Al2^ix	2.93 (2)
Cu2—Al6	2.726 (6)	Li1—Al2^xviii	2.93 (2)
Cu2—Al4	2.759 (4)	Li1—Cu2^xviii	2.93 (2)
Cu2—Al4^vii	2.759 (4)	Li1—Li1^xix	3.07 (8)
Cu2—Li3	2.877 (17)	Li1—Al4^xx	3.207 (19)
Cu2—Li3^vii	2.877 (17)	Li1—Al4^ix	3.207 (19)
Cu2—Li1^iv	2.93 (2)	Li1—Al4^xxi	3.207 (19)
Cu2—Li1^viii	2.93 (2)	Li1—Al4^xviii	3.207 (19)
Al3—Cu1^ix	2.494 (3)	Li2—Li3	2.49 (5)
Cu3—Cu1^x	2.494 (3)	Li2—Li1^xi	2.688 (18)
Cu3—Cu1^iii	2.564 (3)	Li2—Cu1^ix	2.85 (2)
Cu3—Al3^ii	2.690 (5)	Li2—Cu1^x	2.85 (2)
Cu3—Cu3^ii	2.690 (5)	Li2—Cu1^xxii	2.85 (2)
Cu3—Al3^ix	2.690 (5)	Li2—Cu1^xvi	2.85 (2)
Cu3—Cu3^ix	2.690 (5)	Li2—Al4^ix	2.86 (3)
Cu3—Li3	2.710 (10)	Li2—Al4^xxi	2.86 (3)
Cu3—Cu6^xi	2.786 (3)	Li2—Cu3^v	3.12 (2)
Cu3—Al6^xi	2.786 (3)	Li2—Al3^v	3.12 (2)
Cu3—Al6	2.786 (3)	Li2—Al6^xi	3.243 (18)
Cu3—Li2	3.12 (2)	Li2—Cu6^xi	3.243 (18)
Al4—Al4^xii	2.624 (14)	Li2—Cu6^xxiii	3.244 (18)
Al4—Li3	2.63 (3)	Li2—Al6^xxiii	3.244 (18)
Al4—Cu1^iii	2.738 (3)	Li2—Al6^v	3.244 (18)
Al4—Cu1^xiii	2.738 (3)	Li2—Cu6^v	3.244 (18)
Al4—Cu1^v	2.738 (3)	Li3—Al3^v	2.710 (10)
Al4—Al2^xi	2.759 (4)	Li3—Cu3^v	2.710 (10)
Al4—Cu2^xi	2.759 (4)	Li3—Cu1^xiii	2.837 (17)
Al4—Li2^ii	2.86 (3)	Li3—Cu1^v	2.837 (17)
Al4—Li2^viii	2.86 (3)	Li3—Cu1^iii	2.837 (17)
Al4—Li1^iv	3.207 (19)	Li3—Al2^xi	2.877 (17)
Al4—Li1^ii	3.207 (19)	Li3—Cu2^xi	2.877 (17)
Al4—Li1^xiv	3.207 (19)	Li3—Cu6^xxiii	2.985 (11)
Al4—Li1^viii	3.207 (19)	Li3—Al6^xxiii	2.985 (11)
Al6—Cu1^xv	2.624 (4)	Li3—Cu6^v	2.985 (11)
Al6—Cu1^ix	2.624 (4)	Li3—Al6^v	2.985 (11)
Al6—Cu6^v	2.721 (9)	Li3—Cu6^xi	2.985 (11)
Al6—Al6^v	2.721 (9)	Li3—Al6^xi	2.985 (11)
Cu2—Cu1—Cu1^i	59.61 (4)	Cu1^v—Al4—Li2^viii	61.0 (3)
Cu2—Cu1—Al3^ii	178.64 (15)	Al2^xi—Al4—Li2^viii	101.36 (13)
Cu1^i—Cu1—Al3^ii	120.08 (6)	Cu2^xi—Al4—Li2^viii	101.36 (13)
Cu2—Cu1—Cu3^ii	178.64 (15)	Cu2—Al4—Li2^viii	101.36 (13)
Cu1^i—Cu1—Cu3^ii	120.08 (6)	Li2^ii—Al4—Li2^viii	125.5 (7)
Al3^ii—Cu1—Cu3^ii	0.00 (17)	Cu1^xv—Al6—Cu1^ix	56.45 (13)
Cu2—Cu1—Cu1^iii	120.39 (4)	Cu1^xv—Al6—Cu6^v	116.21 (10)
Cu1^i—Cu1—Cu1^iii	180.00 (5)	Cu1^ix—Al6—Cu6^v	116.21 (10)
Al3^ii—Cu1—Cu1^iii	59.92 (6)	Cu1^xv—Al6—Al6^v	116.21 (10)
Cu3^ii—Cu1—Cu1^iii	59.92 (6)	Cu1^ix—Al6—Al6^v	116.21 (10)
Cu2—Cu1—Cu3	114.63 (15)	Cu6^v—Al6—Al6^v	0.00 (13)
Cu1^i—Cu1—Cu3	119.18 (6)	Cu1^xv—Al6—Cu2	151.77 (7)
Al3^ii—Cu1—Cu3	64.24 (15)	Cu1^ix—Al6—Cu2	151.77 (7)
Cu3^ii—Cu1—Cu3	64.24 (15)	Cu6^v—Al6—Cu2	60.07 (11)
Cu1^iii—Cu1—Cu3	60.82 (6)	Al6^v—Al6—Cu2	60.07 (11)
Cu2—Cu1—Cu6^iv	114.48 (12)	Cu1^xv—Al6—Cu1^i	108.27 (11)
Cu1^i—Cu1—Cu6^iv	61.77 (7)	Cu1^ix—Al6—Cu1^i	137.70 (19)
Al3^ii—Cu1—Cu6^iv	65.91 (9)	Cu6^v—Al6—Cu1^i	105.92 (9)
Cu3^ii—Cu1—Cu6^iv	65.91 (9)	Al6^v—Al6—Cu1^i	105.92 (9)
Cu1^iii—Cu1—Cu6^iv	118.23 (7)	Cu2—Al6—Cu1^i	53.17 (9)
Cu3—Cu1—Cu6^iv	117.61 (13)	Cu1^xv—Al6—Cu1	137.70 (19)
Cu2—Cu1—Al6^iv	114.48 (12)	Cu1^ix—Al6—Cu1	108.27 (11)
Cu1^i—Cu1—Al6^iv	61.77 (7)	Cu6^v—Al6—Cu1	105.92 (9)
Al3^ii—Cu1—Al6^iv	65.91 (9)	Al6^v—Al6—Cu1	105.92 (9)
Cu3^ii—Cu1—Al6^iv	65.91 (9)	Cu2—Al6—Cu1	53.17 (9)
Cu1^iii—Cu1—Al6^iv	118.23 (7)	Cu1^i—Al6—Cu1	53.55 (12)
Cu3—Cu1—Al6^iv	117.61 (13)	Cu1^xv—Al6—Al3^vii	54.78 (10)
Cu6^iv—Cu1—Al6^iv	0.00 (10)	Cu1^ix—Al6—Al3^vii	105.60 (16)
Cu2—Cu1—Al4	63.93 (7)	Cu6^v—Al6—Al3^vii	116.40 (11)
Cu1^i—Cu1—Al4	117.16 (5)	Al6^v—Al6—Al3^vii	116.40 (11)
Al3^ii—Cu1—Al4	116.97 (10)	Cu2—Al6—Al3^vii	99.99 (12)
Cu3^ii—Cu1—Al4	116.97 (10)	Cu1^i—Al6—Al3^vii	55.11 (10)
Cu1^iii—Cu1—Al4	62.84 (5)	Cu1—Al6—Al3^vii	103.50 (16)
Cu3—Cu1—Al4	107.41 (15)	Cu1^xv—Al6—Cu3^vii	54.78 (10)
Cu6^iv—Cu1—Al4	127.60 (15)	Cu1^ix—Al6—Cu3^vii	105.60 (16)
Al6^iv—Cu1—Al4	127.60 (15)	Cu6^v—Al6—Cu3^vii	116.40 (11)
Cu2—Cu1—Al6	62.81 (15)	Al6^v—Al6—Cu3^vii	116.40 (11)
Cu1^i—Cu1—Al6	63.23 (6)	Cu2—Al6—Cu3^vii	99.99 (12)
Al3^ii—Cu1—Al6	115.84 (13)	Cu1^i—Al6—Cu3^vii	55.11 (10)
Cu3^ii—Cu1—Al6	115.84 (13)	Cu1—Al6—Cu3^vii	103.50 (16)
Cu1^iii—Cu1—Al6	116.77 (6)	Al3^vii—Al6—Cu3^vii	0.00 (14)
Cu3—Cu1—Al6	63.06 (8)	Cu1^xv—Al6—Cu3	105.60 (16)
Cu6^iv—Cu1—Al6	111.80 (16)	Cu1^ix—Al6—Cu3	54.78 (10)
Al6^iv—Cu1—Al6	111.80 (16)	Cu6^v—Al6—Cu3	116.40 (11)
Al4—Cu1—Al6	111.62 (15)	Al6^v—Al6—Cu3	116.40 (11)
Cu1^v—Cu2—Cu1^vi	60.79 (9)	Cu2—Al6—Cu3	99.99 (12)
Cu1^v—Cu2—Cu1^i	179.0 (3)	Cu1^i—Al6—Cu3	103.50 (16)
Cu1^vi—Cu2—Cu1^i	119.20 (9)	Cu1—Al6—Cu3	55.11 (10)
Cu1^v—Cu2—Cu1	119.20 (9)	Al3^vii—Al6—Cu3	126.8 (2)
Cu1^vi—Cu2—Cu1	179.0 (3)	Cu3^vii—Al6—Cu3	126.8 (2)
Cu1^i—Cu2—Cu1	60.79 (9)	Li2^vii—Li1—Li2	135.8 (18)
Cu1^v—Cu2—Cu6^v	64.02 (11)	Li2^vii—Li1—Cu1^xv	61.5 (3)
Cu1^vi—Cu2—Cu6^v	64.02 (11)	Li2—Li1—Cu1^xv	109.0 (6)
Cu1^i—Cu2—Cu6^v	115.01 (18)	Li2^vii—Li1—Cu1^ix	109.0 (6)
Cu1—Cu2—Cu6^v	115.01 (18)	Li2—Li1—Cu1^ix	61.5 (3)
Cu1^v—Cu2—Al6^v	64.02 (11)	Cu1^xv—Li1—Cu1^ix	51.29 (17)
Cu1^vi—Cu2—Al6^v	64.02 (11)	Li2^vii—Li1—Cu1^xvi	109.0 (6)
Cu1^i—Cu2—Al6^v	115.01 (18)	Li2—Li1—Cu1^xvi	61.5 (3)
Cu1—Cu2—Al6^v	115.01 (18)	Cu1^xv—Li1—Cu1^xvi	156.7 (15)
Cu6^v—Cu2—Al6^v	0.00 (18)	Cu1^ix—Li1—Cu1^xvi	122.9 (6)
Cu1^v—Cu2—Al6	115.01 (18)	Li2^vii—Li1—Cu1^xvii	61.5 (3)
Cu1^vi—Cu2—Al6	115.01 (18)	Li2—Li1—Cu1^xvii	109.0 (6)
Cu1^i—Cu2—Al6	64.02 (11)	Cu1^xv—Li1—Cu1^xvii	122.9 (6)
Cu1—Cu2—Al6	64.02 (11)	Cu1^ix—Li1—Cu1^xvii	156.7 (15)
Cu6^v—Cu2—Al6	59.9 (2)	Cu1^xvi—Li1—Cu1^xvii	51.29 (17)
Al6^v—Cu2—Al6	59.9 (2)	Li2^vii—Li1—Al6	70.6 (8)
Cu1^v—Cu2—Al4	63.06 (6)	Li2—Li1—Al6	70.6 (8)
Cu1^vi—Cu2—Al4	117.42 (10)	Cu1^xv—Li1—Al6	53.9 (4)
Cu1^i—Cu2—Al4	117.42 (10)	Cu1^ix—Li1—Al6	53.9 (4)
Cu1—Cu2—Al4	63.06 (6)	Cu1^xvi—Li1—Al6	103.3 (10)
Cu6^v—Cu2—Al4	111.87 (13)	Cu1^xvii—Li1—Al6	103.3 (10)
Al6^v—Cu2—Al4	111.87 (13)	Li2^vii—Li1—Cu6^v	70.6 (8)
Al6—Cu2—Al4	111.87 (13)	Li2—Li1—Cu6^v	70.6 (8)
Cu1^v—Cu2—Al4^vii	117.42 (10)	Cu1^xv—Li1—Cu6^v	103.3 (10)
Cu1^vi—Cu2—Al4^vii	63.06 (6)	Cu1^ix—Li1—Cu6^v	103.3 (10)
Cu1^i—Cu2—Al4^vii	63.06 (6)	Cu1^xvi—Li1—Cu6^v	53.9 (4)
Cu1—Cu2—Al4^vii	117.42 (10)	Cu1^xvii—Li1—Cu6^v	53.9 (4)
Cu6^v—Cu2—Al4^vii	111.87 (13)	Al6—Li1—Cu6^v	55.6 (7)
Al6^v—Cu2—Al4^vii	111.87 (13)	Li2^vii—Li1—Al6^v	70.6 (8)
Al6—Cu2—Al4^vii	111.87 (13)	Li2—Li1—Al6^v	70.6 (8)
Al4—Cu2—Al4^vii	129.1 (3)	Cu1^xv—Li1—Al6^v	103.3 (10)
Cu1^v—Cu2—Li3	63.74 (17)	Cu1^ix—Li1—Al6^v	103.3 (10)
Cu1^vi—Cu2—Li3	115.7 (2)	Cu1^xvi—Li1—Al6^v	53.9 (4)
Cu1^i—Cu2—Li3	115.7 (2)	Cu1^xvii—Li1—Al6^v	53.9 (4)
Cu1—Cu2—Li3	63.74 (17)	Al6—Li1—Al6^v	55.6 (7)
Cu6^v—Cu2—Li3	64.3 (5)	Cu6^v—Li1—Al6^v	0.00 (17)
Al6^v—Cu2—Li3	64.3 (5)	Li2^vii—Li1—Cu2^ix	101.4 (4)
Al6—Cu2—Li3	64.3 (5)	Li2—Li1—Cu2^ix	101.4 (4)
Al4—Cu2—Li3	55.5 (6)	Cu1^xv—Li1—Cu2^ix	50.02 (14)
Al4^vii—Cu2—Li3	175.4 (6)	Cu1^ix—Li1—Cu2^ix	50.02 (14)
Cu1^v—Cu2—Li3^vii	115.7 (2)	Cu1^xvi—Li1—Cu2^ix	148.7 (9)
Cu1^vi—Cu2—Li3^vii	63.74 (17)	Cu1^xvii—Li1—Cu2^ix	148.7 (9)
Cu1^i—Cu2—Li3^vii	63.74 (17)	Al6—Li1—Cu2^ix	93.8 (3)
Cu1—Cu2—Li3^vii	115.7 (2)	Cu6^v—Li1—Cu2^ix	149.4 (10)
Cu6^v—Cu2—Li3^vii	64.3 (5)	Al6^v—Li1—Cu2^ix	149.4 (10)
Al6^v—Cu2—Li3^vii	64.3 (5)	Li2^vii—Li1—Al2^ix	101.4 (4)
Al6—Cu2—Li3^vii	64.3 (5)	Li2—Li1—Al2^ix	101.4 (4)
Al4—Cu2—Li3^vii	175.4 (6)	Cu1^xv—Li1—Al2^ix	50.02 (14)
Al4^vii—Cu2—Li3^vii	55.5 (6)	Cu1^ix—Li1—Al2^ix	50.02 (14)
Li3—Cu2—Li3^vii	120.0 (12)	Cu1^xvi—Li1—Al2^ix	148.7 (9)
Cu1^ix—Cu3—Cu1^x	60.16 (12)	Cu1^xvii—Li1—Al2^ix	148.7 (9)
Cu1^ix—Cu3—Cu1	119.13 (9)	Al6—Li1—Al2^ix	93.8 (3)
Cu1^x—Cu3—Cu1	167.30 (17)	Cu6^v—Li1—Al2^ix	149.4 (10)
Cu1^ix—Cu3—Cu1^iii	167.30 (17)	Al6^v—Li1—Al2^ix	149.4 (10)
Cu1^x—Cu3—Cu1^iii	119.13 (9)	Cu2^ix—Li1—Al2^ix	0.00 (17)
Cu1—Cu3—Cu1^iii	58.35 (11)	Li3—Li2—Li1^xi	112.1 (9)
Cu1^ix—Cu3—Al3^ii	134.18 (10)	Li3—Li2—Li1	112.1 (9)
Cu1^x—Cu3—Al3^ii	134.18 (10)	Li1^xi—Li2—Li1	135.8 (18)
Cu1—Cu3—Al3^ii	56.61 (13)	Li3—Li2—Cu1^ix	98.7 (7)
Cu1^iii—Cu3—Al3^ii	56.61 (13)	Li1^xi—Li2—Cu1^ix	110.5 (6)
Cu1^ix—Cu3—Cu3^ii	134.18 (10)	Li1—Li2—Cu1^ix	62.4 (2)
Cu1^x—Cu3—Cu3^ii	134.18 (10)	Li3—Li2—Cu1^x	98.7 (7)
Cu1—Cu3—Cu3^ii	56.61 (13)	Li1^xi—Li2—Cu1^x	62.4 (2)
Cu1^iii—Cu3—Cu3^ii	56.61 (13)	Li1—Li2—Cu1^x	110.5 (6)
Al3^ii—Cu3—Cu3^ii	0.000 (17)	Cu1^ix—Li2—Cu1^x	52.12 (14)
Cu1^ix—Cu3—Al3^ix	59.14 (13)	Li3—Li2—Cu1^xxii	98.7 (7)
Cu1^x—Cu3—Al3^ix	59.14 (13)	Li1^xi—Li2—Cu1^xxii	62.4 (2)
Cu1—Cu3—Al3^ix	132.68 (10)	Li1—Li2—Cu1^xxii	110.5 (6)
Cu1^iii—Cu3—Al3^ix	132.68 (10)	Cu1^ix—Li2—Cu1^xxii	162.6 (15)
Al3^ii—Cu3—Al3^ix	90.0	Cu1^x—Li2—Cu1^xxii	124.6 (4)
Cu3^ii—Cu3—Al3^ix	90.0	Li3—Li2—Cu1^xvi	98.7 (7)
Cu1^ix—Cu3—Cu3^ix	59.14 (13)	Li1^xi—Li2—Cu1^xvi	110.5 (6)
Cu1^x—Cu3—Cu3^ix	59.14 (13)	Li1—Li2—Cu1^xvi	62.4 (2)
Cu1—Cu3—Cu3^ix	132.68 (10)	Cu1^ix—Li2—Cu1^xvi	124.6 (4)
Cu1^iii—Cu3—Cu3^ix	132.68 (10)	Cu1^x—Li2—Cu1^xvi	162.6 (15)
Al3^ii—Cu3—Cu3^ix	90.0	Cu1^xxii—Li2—Cu1^xvi	52.11 (14)
Cu3^ii—Cu3—Cu3^ix	90.0	Li3—Li2—Al4^ix	152.8 (3)
Al3^ix—Cu3—Cu3^ix	0.00 (15)	Li1^xi—Li2—Al4^ix	70.5 (8)
Cu1^ix—Cu3—Li3	102.4 (6)	Li1—Li2—Al4^ix	70.5 (8)
Cu1^x—Cu3—Li3	102.4 (6)	Cu1^ix—Li2—Al4^ix	57.3 (4)
Cu1—Cu3—Li3	65.0 (6)	Cu1^x—Li2—Al4^ix	57.3 (4)
Cu1^iii—Cu3—Li3	65.0 (6)	Cu1^xxii—Li2—Al4^ix	105.7 (10)
Al3^ii—Cu3—Li3	112.0 (7)	Cu1^xvi—Li2—Al4^ix	105.7 (10)
Cu3^ii—Cu3—Li3	112.0 (7)	Li3—Li2—Al4^xxi	152.7 (3)
Al3^ix—Cu3—Li3	158.0 (7)	Li1^xi—Li2—Al4^xxi	70.5 (8)
Cu3^ix—Cu3—Li3	158.0 (7)	Li1—Li2—Al4^xxi	70.5 (8)
Cu1^ix—Cu3—Cu6^xi	112.68 (16)	Cu1^ix—Li2—Al4^xxi	105.7 (10)
Cu1^x—Cu3—Cu6^xi	59.30 (11)	Cu1^x—Li2—Al4^xxi	105.7 (10)
Cu1—Cu3—Cu6^xi	113.55 (15)	Cu1^xxii—Li2—Al4^xxi	57.3 (4)
Cu1^iii—Cu3—Cu6^xi	61.83 (11)	Cu1^xvi—Li2—Al4^xxi	57.3 (4)
Al3^ii—Cu3—Cu6^xi	108.68 (13)	Al4^ix—Li2—Al4^xxi	54.5 (7)
Cu3^ii—Cu3—Cu6^xi	108.68 (13)	Li3—Li2—Cu3	56.4 (6)
Al3^ix—Cu3—Cu6^xi	108.26 (13)	Li1^xi—Li2—Cu3	102.0 (4)
Cu3^ix—Cu3—Cu6^xi	108.26 (13)	Li1—Li2—Cu3	102.0 (4)
Li3—Cu3—Cu6^xi	65.76 (18)	Cu1^ix—Li2—Cu3	49.16 (19)
Cu1^ix—Cu3—Al6^xi	112.68 (16)	Cu1^x—Li2—Cu3	49.16 (19)
Cu1^x—Cu3—Al6^xi	59.30 (11)	Cu1^xxii—Li2—Cu3	145.2 (9)
Cu1—Cu3—Al6^xi	113.55 (15)	Cu1^xvi—Li2—Cu3	145.2 (9)
Cu1^iii—Cu3—Al6^xi	61.83 (11)	Al4^ix—Li2—Cu3	96.3 (3)
Al3^ii—Cu3—Al6^xi	108.68 (13)	Al4^xxi—Li2—Cu3	150.8 (9)
Cu3^ii—Cu3—Al6^xi	108.68 (13)	Li3—Li2—Cu3^v	56.4 (6)
Al3^ix—Cu3—Al6^xi	108.26 (13)	Li1^xi—Li2—Cu3^v	102.0 (4)
Cu3^ix—Cu3—Al6^xi	108.26 (13)	Li1—Li2—Cu3^v	102.0 (4)
Li3—Cu3—Al6^xi	65.76 (18)	Cu1^ix—Li2—Cu3^v	145.2 (9)
Cu6^xi—Cu3—Al6^xi	0.0	Cu1^x—Li2—Cu3^v	145.2 (9)
Al4^xii—Al4—Li3	179.998 (1)	Cu1^xxii—Li2—Cu3^v	49.15 (19)
Al4^xii—Al4—Cu1	116.17 (13)	Cu1^xvi—Li2—Cu3^v	49.15 (19)
Li3—Al4—Cu1	63.8 (5)	Al4^ix—Li2—Cu3^v	150.8 (9)
Al4^xii—Al4—Cu1^iii	116.17 (13)	Al4^xxi—Li2—Cu3^v	96.3 (3)
Li3—Al4—Cu1^iii	63.83 (13)	Cu3—Li2—Cu3^v	112.8 (11)
Cu1—Al4—Cu1^iii	54.31 (11)	Li2—Li3—Al4	179.989 (1)
Al4^xii—Al4—Cu1^xiii	116.17 (13)	Li2—Li3—Al3^v	73.6 (7)
Li3—Al4—Cu1^xiii	63.83 (13)	Al4—Li3—Al3^v	106.5 (7)
Cu1—Al4—Cu1^xiii	127.7 (3)	Li2—Li3—Cu3^v	73.6 (7)
Cu1^iii—Al4—Cu1^xiii	101.20 (17)	Al4—Li3—Cu3^v	106.5 (7)
Al4^xii—Al4—Cu1^v	116.17 (13)	Al3^v—Li3—Cu3^v	0.00 (7)
Li3—Al4—Cu1^v	63.83 (13)	Li2—Li3—Cu3	73.5 (7)
Cu1—Al4—Cu1^v	101.20 (17)	Al4—Li3—Cu3	106.4 (7)
Cu1^iii—Al4—Cu1^v	127.7 (3)	Al3^v—Li3—Cu3	147.1 (14)
Cu1^xiii—Al4—Cu1^v	54.31 (11)	Cu3^v—Li3—Cu3	147.1 (14)
Al4^xii—Al4—Al2^xi	115.46 (16)	Li2—Li3—Cu1^xiii	120.0 (6)
Li3—Al4—Al2^xi	64.54 (16)	Al4—Li3—Cu1^xiii	60.0 (6)
Cu1—Al4—Al2^xi	102.86 (17)	Al3^v—Li3—Cu1^xiii	54.99 (12)
Cu1^iii—Al4—Al2^xi	53.01 (8)	Cu3^v—Li3—Cu1^xiii	54.99 (12)
Cu1^xiii—Al4—Al2^xi	53.01 (8)	Cu3—Li3—Cu1^xiii	149.0 (6)
Cu1^v—Al4—Al2^xi	102.86 (17)	Li2—Li3—Cu1^v	120.0 (6)
Al4^xii—Al4—Cu2^xi	115.46 (16)	Al4—Li3—Cu1^v	60.0 (6)
Li3—Al4—Cu2^xi	64.54 (16)	Al3^v—Li3—Cu1^v	54.99 (12)
Cu1—Al4—Cu2^xi	102.86 (17)	Cu3^v—Li3—Cu1^v	54.99 (12)
Cu1^iii—Al4—Cu2^xi	53.01 (8)	Cu3—Li3—Cu1^v	149.0 (6)
Cu1^xiii—Al4—Cu2^xi	53.01 (8)	Cu1^xiii—Li3—Cu1^v	52.3 (3)
Cu1^v—Al4—Cu2^xi	102.86 (17)	Li2—Li3—Cu1	120.0 (6)
Al2^xi—Al4—Cu2^xi	0.00 (15)	Al4—Li3—Cu1	60.0 (6)
Al4^xii—Al4—Cu2	115.46 (16)	Al3^v—Li3—Cu1	149.0 (6)
Li3—Al4—Cu2	64.54 (16)	Cu3^v—Li3—Cu1	149.0 (6)
Cu1—Al4—Cu2	53.01 (8)	Cu3—Li3—Cu1	54.99 (12)
Cu1^iii—Al4—Cu2	102.86 (17)	Cu1^xiii—Li3—Cu1	120.0 (12)
Cu1^xiii—Al4—Cu2	102.86 (17)	Cu1^v—Li3—Cu1	96.4 (8)
Cu1^v—Al4—Cu2	53.01 (8)	Li2—Li3—Cu1^iii	120.0 (6)
Al2^xi—Al4—Cu2	129.1 (3)	Al4—Li3—Cu1^iii	60.0 (6)
Cu2^xi—Al4—Cu2	129.1 (3)	Al3^v—Li3—Cu1^iii	149.0 (6)
Al4^xii—Al4—Li2^ii	62.7 (3)	Cu3^v—Li3—Cu1^iii	149.0 (6)
Li3—Al4—Li2^ii	117.3 (3)	Cu3—Li3—Cu1^iii	54.99 (12)
Cu1—Al4—Li2^ii	61.0 (3)	Cu1^xiii—Li3—Cu1^iii	96.4 (8)
Cu1^iii—Al4—Li2^ii	61.0 (3)	Cu1^v—Li3—Cu1^iii	120.0 (12)
Cu1^xiii—Al4—Li2^ii	152.74 (5)	Cu1—Li3—Cu1^iii	52.3 (3)
Cu1^v—Al4—Li2^ii	152.74 (5)	Li2—Li3—Cu2	120.0 (6)
Al2^xi—Al4—Li2^ii	101.35 (13)	Al4—Li3—Cu2	60.0 (6)
Cu2^xi—Al4—Li2^ii	101.35 (13)	Al3^v—Li3—Cu2	98.15 (19)
Cu2—Al4—Li2^ii	101.35 (13)	Cu3^v—Li3—Cu2	98.15 (19)
Al4^xii—Al4—Li2^viii	62.7 (3)	Cu3—Li3—Cu2	98.14 (19)
Li3—Al4—Li2^viii	117.3 (3)	Cu1^xiii—Li3—Cu2	97.5 (8)
Cu1—Al4—Li2^viii	152.74 (5)	Cu1^v—Li3—Cu2	50.8 (3)
Cu1^iii—Al4—Li2^viii	152.74 (5)	Cu1—Li3—Cu2	50.8 (3)
Cu1^xiii—Al4—Li2^viii	61.0 (3)	Cu1^iii—Li3—Cu2	97.5 (8)

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