On the possibility for Rb- and Eu-cation ordering in type-I clathrates: synthesis and homogeneity range of the novel compounds Rb_8–xEu_x(In,Ge)₄₆ (0.6 ≤ x ≤ 1.8)

Studies in the Rb–Eu–In–Ge system confirm the existence of the phase Rb_8−xEu_x(In,Ge)₄₆ (0.6 ≤ x ≤ 1.8), crystallizing with the cubic clathrate type-I structure. The In and Ge content can be varied, concomitant with changes in the Rb–Eu ratio. Two of the three framework sites are occupied by statistical mixtures of Ge and In atoms, while the site with the lowest multiplicity is taken by the In atoms only. Based on the three refined formulae [hepta­rubidium europium nona­indium hepta­triaconta­germanide, Rb_7.39(3)Eu_0.61(3)In_8.88(5)Ge_37.12(5), and two forms of hexa­rubidium dieuropium deca­indium hexa­triaconta­germanide, Rb_6.30(3)Eu_1.70(3)In_9.76(4)Ge_36.24(4) and Rb_6.24(2)Eu_1.76(2)In_10.16(5)Ge_35.84(5)] and the explored different synthetic routes, it can be suggested that the known ternary phase Rb₈In₈Ge₃₈ and the hypothetical quaternary phase Rb₆Eu₂In₁₀Ge₃₆ represent the boundaries of the homogeneity range. In the former limiting composition, both the (Ge,In)₂₀ and the (Ge,In)₂₄ cages are fully occupied by Rb atoms only, whereas Rb₆Eu₂In₁₀Ge₃₆ has Rb atoms encapsulated in the larger tetra­kaideca­hedra, with Eu atoms filling the smaller penta­gonal dodeca­hedra. For the solid solutions Rb_8−xEu_x(In,Ge)₄₆, Rb and Eu are statistically disordered in the dodeca­hedral cage, and the tetra­kaideca­hedral cage is only occupied by Rb atoms.

S1. Introduction

In the last two decades, cage compounds with clathrate structures have received renewed inter­est due to their proposed potential as thermoelectric materials (Slack, 1995; Nolas et al., 1998; Sales et al., 1999; Christensen et al., 2010). The open-framework structures of these materials are based on tetra­hedrally coordinated Si, Ge and Sn. There are large cages left behind, which are capable of encapsulating guest atoms (typically alkali metals, alkaline-earth metals or the nominally divalent rare-earth metal Eu). During the preparation of this manuscript, the rare earth metals La and Ce were reported, for the first time, as guest atoms in the structure of Ba_8–xLn_xAu_ySi_46–x (Prokofiev et al., 2013).

Clathrates crystallize in different structure types, whereby the most common structure types are the type-I structure with general formula A₈M₄₆ (A denotes guest atoms and M denotes framework atoms; cubic, Pm3n, Pearson symbol cP54) and the type-II structure with general formula A₂₄M₁₃₆ (cubic, Fd3m, Pearson symbol cF160). Both formulas represent the limiting compositions with full occupation of all cages by guest atoms and without any defects (vacancies) in the framework. Fractional occupation of the cages by the guest atoms, as well as missing atoms on the framework sites are common traits of the crystal chemistry of the clathrates; these issues have been analyzed in the past in many previous publications and we refer the reader to some recent review articles on the subject (Bobev & Sevov, 2000; Beekman & Nolas, 2008; Shevelkov & Kovnir, 2011). The compositions are further complicated by the possible partial substitution of the framework-building Group 14 atoms with atoms of Group 12 and 13 elements, or even late transition metals from Groups 10 and 11, as well as by insertion of two different guest atoms (Bobev & Sevov, 1999, 2000; Nolas et al., 2002; Bobev et al., 2006; Paschen et al., 2006; Beekman et al., 2007, 2009; Schäfer & Bobev, 2013a; Prokofiev et al., 2013).

S2. Experimental

S2.1. Synthesis and crystallization

All synthetic manipulations were carried out in an argon-filled glove-box or under vacuum. The elements were purchased from Alfa or Sigma–Aldrich with purity greater than 99.9%.

Rb_8–xEu_x(In,Ge)₄₆ can be obtained with three different synthetic routes: (i) by fusing together the elements, (ii) by using a multi-step synthesis (i.e. precursors) and (iii) by In-flux reactions.

For synthetic route (i), in our initial experiments, the nominal composition Rb₆Eu₂In₁₀Ge₃₆ was the target, and the starting materials were loaded in this ratio. The Nb tubes were always arc-sealed and enclosed in fused-silica jackets before the heat treatments. The samples were heated in programmable tube furnaces to 1223 K (rate 100 K h^-1), kept for 2 h, cooled to 873 K (rate 150 K h^-1), annealed at this temperature for 96 h and cooled to room temperature with a rate of 5 K h^-1. None of these experiments proceed as desired – side products were always present, and a slight excess of Eu was needed to avoid the formation of Rb₈In₈Ge₃₈ (von Schnering et al., 1998). An additional problem was the reaction of Ge with the Nb tube, which prompted us to look at prereacting Eu and Ge (the elements with highest melting points), and to lower the reaction temperature.

As a result, we came up with a different procedure, i.e. (ii). EuIn₄ and RbGe were synthesized in a first step by fusing together the elements in stoichiometric ratios (Eu–In = 1:4 and Rb–Ge = 1:1) in Nb tubes. The products obtained were carefully ground to a fine powder and used in the second step, also carried out in Nb tubes. The mixtures were heated to 898 K (rate 100 K h^-1), annealed for 60 h and cooled to room temperature (rate 20 K h^-1). The products obtained were reground and additional Eu was added. In the final step, the reaction mixture was heated to 1123 K (rate 10 K h^-1), kept for 1 h, cooled to 873 K (15 K h^-1), annealed for 96 h and cooled to room temperature (rate 5 K h^-1).

For the flux reaction (iii), the elements were loaded with the Rb–Eu–In–Ge ratio 6:6:40:40 in longer Nb tubes (length 8 cm, diameter 1 cm). After insertion of a filter part (a round Nb sheet with small drilled holes), the Nb tubes were heated to 1073 K (rate 100 K h^-1), annealed for 60 h and cooled slowly (rate 5 K h^-1). The In flux was removed at 573 K.

The compositions of the synthesized phases were confirmed by EDX measurements on a Jeol 7400 F electron microscope equipped with an INCA–OXFORD energy-dispersive spectrometer.

Powder patterns were taken at room temperature on a Rigaku MiniFlex powder diffractometer using filtered Cu Kα radiation (λ = 1.54056 Å). The data were used for phase-identification only. Irrespective of the method of synthesis, single-phase product was never obtained.

Differential scanning calorimetry and thermogravimetric (DSC–TG) analyses for different batches were carried out using a calorimeter supplied by TA Instruments (model SDT Q600). The samples were ground into powders and loaded in small alumina pans. The temperature of a typical run was ramped at a rate of 10 K under a constant flow (100 ml min^-1) of high purity argon in order to avoid oxidation in ambient air.

S2.2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. The contrast between the X-ray atomic scattering factors between Ge and In, as well as between Rb and Eu, is significant enough to allow precise refinements of the site-occupation factors. In all cases, the occupancies of the framework sites were first freely refined and then fixed, allowing for the final refinements of the sites for the guest atoms. Afterwards, the occupancies of all Ge/In sites were refined by freeing the occupancy of each individual site, while the remaining occupancies [OK?] were kept fixed. The 24k and 16i sites were found to be mixed occupied by both atoms, while site 6c is only occupied by In atoms. There were no hints in the refinements for vacancies in the framework. The isotropic displacement parameter for Rb at site 6d is slightly larger than the rest, and the oblate shape of the spheroid might suggest an off-centering of the atom occupying this large tetra­kaidecahedral cage, as discussed by us in a related study (Schäfer & Bobev, 2013b). However, refinements with a split site model (24k) did not yield statistically significant improvements.

The atomic coordinates were standardized to conform to the literature prior to the final anisotropic refinement. Final difference Fourier maps were flat. The small residual peaks are located at (0.2476, 0.1417, 0) for compound (I) (0.72 e^- Å^-3), at (0.3609, 0.5, 0.1834) for compound (II) (0.43 e^- Å^-3) and at (0, 0.3667, 0.2130) for compound (III) (0.75 e^- Å^-3). The corresponding holes are at (0.5, 0.2524, 0.0362) for compound (I) (-1.08 e^- Å^-3), at (0.1267, 0.5, 0) for compound (II) (-0.70 e^- Å^-3) and at (0, 0, 0.0391) for compound (III) (-1.07 e^- Å^-3).

S3. Results and discussion

The title compounds adopt the cubic type-I structure with the space group Pm3n (No. 223). The open-framework consists of 46 tetra­hedrally coordinated atoms per unit cell, located on the Wyckoff sites 24k, 16i and 6c. In total, one unit cell contains two (Ge,In)₂₀ penta­gonal dodecahedra and six (Ge,In)₂₄ tetra­kaidecahedra (Fig. 1). The 24-atom polyhedra share their two hexagonal faces to create three perpendicular, but not inter­penetrating, columns running along [100], [010] and [001] of the cube, and entrapping the `isolated' 20-atom polyhedra. In all three reported clathrates, the framework site 6c is refined as fully occupied by In, while in the known Rb₈In₈Ge₃₈ (von Schnering et al., 1998), the same site is a 9:1 mixture of In and Ge. The other two framework sites, namely 24k and 16i, are occupied predominantly by Ge, with very small amounts of In substitutions.

The refined Ge–In ratios are summarized for easier comparison in Table 2. The preference for the In atoms on site 6c can be understood from the point of view of requiring minimization of homoatomic In···In inter­actions. Additionally, In occupying the 6c site allows for elongation of the Ge1/In1–In3 bonds, as seen by comparing their values with other Ge/In–Ge/In distances (Table 3). The Ge/In—Ge/In distances here match closely the values reported for other Ge-based clathrates. We also note that assuming only Ge—Ge bonding between 24k and 16i sites, the corresponding distances on the order of 2.5 Å should signify relatively strong covalent bonds – this conclusion can be deduced from the separation of 2.45 Å between Ge atoms in the elemental form (Pauling, 1960).

The cages themselves are fully occupied by the Rb and Eu guest atoms. The penta­gonal dodecahedra encapsulate statistically disordered Rb and Eu atoms (site 2a) (Fig. 2). The filler atoms for the larger tetra­kaidecahedral polyhedra are exclusively Rb atoms (site 6d). We note here that Eu prefers the 2a site by a large margin, suggesting that if the Eu content can be increased, full ordering of the cations might be possible. The site preferences here can be rationalized taking into account the smaller size of the Eu atoms (r_Eu = 2.08 Å; Pauling, 1960) and the much larger size of the Rb atoms (r_Rb = 2.48 Å; Pauling, 1960). Apparently, the latter are appropriate to fit in the larger cavities, while Eu is suitable for the smaller 20-atom cages only. Notice that we used the Pauling metallic radii to illustrate our reasoning, the same conclusion could be reached if one were to use ionic radii (limited to much smaller coordination numbers).

The sizes of Eu and Rb can apparently be linked to the relatively higher abundance of Rb-containing clathrates relative to Eu-containing ones. Inspecting the literature reveals that only very few clathrates host Eu atoms as guest atoms. The most prominent ones are the type-I and type-VIII phase with formula Eu₈Ga₁₆Ge₃₀ (Paschen et al., 2001). They have same nominal compositions and undergo a reversible phase transition at 969 K from type-VIII to type-I (Paschen et al., 2001). The magnetic and electronic properties of these compounds are already studied extensively (Paschen et al., 2001; Sales et al., 2001; Bentien et al., 2005) and compared with these of Eu_8–xSr_xGa₁₆Ge₃₀ (x = 2, 4) (Woods et al. 2006; Phan et al., 2011). Additionally, some quaternary type-I clathrates with Eu are also known, viz. K₆Eu₂Ga₁₀Ge₃₆ (very close structurally to the structures discussed herein) and K₆Eu₂T₅Ge₄₁, with T = Zn and Cd (Paschen et al., 2006).

The homogeneity range in Rb_8–xEu_x(In,Ge)₄₆ is another issue related to the size of the guest atoms. Inspecting the experimental details, one would immediately notice that the observed unit cells vary monotonically as a function of `x', and the structure with the highest amount Eu (x ≈ 1.8) has the largest unit cell among all: Rb_7.39 (3)Eu_0.61 (3)(In,Ge)₄₆ [a = 11.0292 (9) Å], Rb_6.30 (3)Eu_1.70 (3)(In,Ge)₄₆ [a = 11.0592 (3) Å] and Rb_6.24 (2)Eu_1.76 (2)(In,Ge)₄₆ [a = 11.0614 (7) Å]. Another relevant observation is that Rb₈In₈Ge₃₈ (von Schnering et al., 1998) is reported with a = 11.033 (2) Å, which is very close to our structure with the lowest amount Eu (x ≈ 0.6). The two numbers, however, should be compared with a degree of caution, since the literature value was determined at room temperature, while our data were gathered at 200 K.

Evidently, the trend above does not correlate with the decreased atomic size of Eu relative to that of Rb (Pauling, 1960) – instead, the reason why the structure expands the way it does is the proportional increase of In as Eu replaces Rb. This increase in the amount of In substituting Ge in the framework is required by the Zintl–Klemm concept (Miller, 1996; Guloy, 2006), which can be successfully applied to rationalize the structure. Accordingly, in order to obtain the electroneutrality of the compound, assuming a `2+' state for Eu, the above discussed compounds will have idealized formulas, which can be broken down as follows: [Rb⁺]₈[4b-In^1-]₈[4b-Ge⁰]₃₈, [Rb⁺]₇[Eu²⁺]₁[4b-In^1-]₉ [4b-Ge⁰]₃₇ and [Rb⁺]₆[Eu²⁺]₂ [4b-In^1-]₁₀[4b-Ge⁰]₃₆ (4b-In denotes 4-bonded In atom, which requires an extra electron to form four covalent bonds, and hence, a formal charge of -1).

Clearly, more Eu content in the structure calls for an increasing substitution rate of In for Ge, and since In is larger than Ge (Pauling, 1960) the unit-cell volume increases. Similar dependence of the unit cell (but in an opposite direction) has been reported recently for the type-II clathrates K_xBa_16–x□₈(Ga,Sn)₁₃₆ (□: vacancy; 0.8 ≤ x ≤ 12.9) (Schäfer & Bobev, 2013a,b), where the smaller Ga replaces Sn in the framework. Similar phenomena concerning the unit-cell parameters are known even for more exotic cases, such as Si_46–xP_xTe_y [6.6 (1) ≤ y ≤ 7.5 (1), x ≤ 2y], where introduction of Te instead of a vacancy leads to the contraction of the framework (Zaikina et al., 2009).

Considering Rb₈In₈Ge₃₈ (von Schnering et al., 1998) as an end member, one can ask the question if the amount of Eu replacing Rb is limited to x ≤ 1.8? We have wondered about that too, and had attempted numerous attempts to extend the phase width further; we have also tried to make the pure Eu version (i.e. Eu₈In₁₆Ge₃₀), but none of these experiments have been successful so far. This is perhaps due to the fact that Eu is smaller than the empty space provided by the 24-atom tetra­kaidecahedra, which comprise 3/4 of the sites available for guest-atom fillers. Furthermore, the increase in Eu-content will require an additional increase of the unit-cell volumes due to the higher In-uptake, which could be the reason why the hypothetical Rb₆Eu₂In₁₀Ge₃₆ may very well represent the boundaries of the homogeneity range.

Another issue with regard to the Eu content is that it appears to be very sensitive to the chosen experimental conditions. Our experiments with both classic solid-state methods (direct fusion of elements at high temperature) or using metal fluxes as a `milder' synthetic route suggest that maximum Eu-content can be reached by both types of reactions – In self-flux or fusing together stoichiometric amounts of the elements. The crystals obtained from excess molten In and the crystals obtained from a stochiometric melt (same loading composition except for In) had nearly the same refined formulas, viz. Rb<sub>6.24 (2)</sub>Eu<sub>1.76 (2)</sub>In<sub>10.16 (5)</sub>Ge<sub>35.84 (5)</sub> for the former and Rb<sub>6.30 (3)</sub>Eu<sub>1.70 (3)</sub>In<sub>9.76 (4)</sub>Ge<sub>36.24 (4)</sub> for the latter. In both cases, some Eu was `lost' due to the formation of the EuIn₄ and EuGe₂ binary phases as unwanted side products, and we could not find conditions to fully circumvent them. We also note explicitly that the compositions vary in each single batch – for instance the phase Rb_7.39 (3)Eu_0.61 (3)In_8.88 (5)Ge_37.12 (5) [a = 11.0292 (9) Å] was found in a reaction that also yielded crystals indexed with a = 11.047 (2) Å. The latter were of inferior quality and their composition could not be established by refinements of the X-ray data, but judging from the unit-cell parameters, one has considerably lower Eu content. EDX analyses of different single crystals (3–4 per batch) also confirm the lack of homogeneity. The same argument is further supported by the DSC curves, which show peritectic decomposition of the studied clathrates, however, not at a sharp temperature point – there is a relatively wide range between 1143 to 1173 K. In comparison, the melting point of type-I Eu₈Ga₁₆Ge₃₀ is 972 K (Paschen et al., 2001).

Based on the above, it can be argued that the controlled and reproducible synthesis of the quaternary clathrates Rb_8–xEu_x(In,Ge)₄₆ will only be possible using different synthetic methods, or if high-temperature routes are involved, prolonged equilibration steps should be used to ensure uniformity.

Last, we also would like to compare the closely related K₆Eu₂Ga₁₀Ge₃₆, which has been described earlier as a line compound (Paschen et al., 2006). In this case, the 24-atom cages are filled only by K atoms (r_K = 2.35 Å; Pauling, 1960) and the 20-atom polyhedra only by Eu (Paschen et al., 2006). The paper, however, does not report single-crystal refinements of the occupancies which can be compared with ours. The same authors also describe K₆Eu₂T₅Ge₄₁ with T = Zn and Cd, where the smaller atom size of the substituting framework atoms T (r_Zn = 1.34 Å and r_Ge = 1.44 Å; Pauling, 1960) causes a contraction of the unit cell. Cd atoms have nearly the same size as In atoms (r_Cd = 1.51 Å and r_In = 1.58 Å; Pauling, 1960); however, only about half the amount of Cd atoms is present. This, of course, is not only due to the size of Cd versus In, the formal charge of 2- for Cd and 1- for In must also be taken under consideration (i.e. as discussed above, the Zintl–Klemm rules should apply, calling for the formulation [K⁺]₆[Eu²⁺]₂[4b-Cd^2-]₅[4b-Ge⁰]₄₁).

Related literature

For related literature, see: Beekman & Nolas (2008); Beekman et al. (2007, 2009); Bentien et al. (2005); Bobev & Sevov (1999, 2000); Bobev et al. (2006); Christensen et al. (2010); Guloy (2006); Miller (1996); Nolas et al. (1998, 2002); Paschen et al. (2001, 2006); Pauling (1960); Phan et al. (2011); Prokofiev et al. (2013); Sales et al. (1999, 2001); Schäfer & Bobev (2013a, 2013b); Schnering et al. (1998); Shevelkov & Kovnir (2011); Slack (1995); Woods et al. (2006); Zaikina et al. (2009).

Computing details

For all compounds, data collection: SMART (Bruker, 2002); cell refinement: SMART (Bruker, 2002); data reduction: SAINT (Bruker, 2002); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: CrystalMaker (CrystalMaker, 2007); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

Fig. 1. View of the polyanionic framework of the type-I clathrates (colour coding for the electronic version of the paper: pentagonal dodecahedra are purple and tetrakaidecahedra are yellow). The framework site 6c, taken by the In atoms, is highlighted in light blue.

Fig. 2. Representation of the polyhedral cages in (a) Rb7.39 (3)Eu0.61 (3)In8.88 (5)Ge37.12 (5), (b) Rb6.30 (3)Eu1.70 (3)In9.76 (4)Ge36.24 (4) and (c) Rb6.24 (2)Eu1.76 (2)In10.16 (5)Ge35.84 (5). The anisotropic displacement parameters are drawn at the 95% probability level. In all electronic version of the plots, the framework sites are colour coded as follows: 6c is light blue, 16i is dark blue, and 24k is shown in black. The Rb and Eu atoms co-occuying site 2a are shown in purple and the Rb at site 6d are drawn in yellow.

(I) Heptarubidium europium nonaindium heptatriacontagermanide

Crystal data

Rb7.39Eu0.61In8.88Ge37.12	Dx = 5.494 Mg m^−3
Mr = 4438.46	Mo Kα radiation, λ = 0.71073 Å
Cubic, Pm3n	Cell parameters from 1008 reflections
Hall symbol: -P 4n 2 3	θ = 4.1–26.9°
a = 11.0292 (9) Å	µ = 31.51 mm^−1
V = 1341.63 (19) Å^3	T = 200 K
Z = 1	Irregular, silver–grey
F(000) = 1935	0.16 × 0.11 × 0.11 mm

Data collection

Bruker SMART APEX CCD diffractometer	324 independent reflections
Radiation source: fine-focus sealed tube	298 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.057
ω and ϕ scans	θmax = 28.1°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 2008)	h = −14→14
Tmin = 0.081, Tmax = 0.137	k = −14→14
12572 measured reflections	l = −14→14

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)] = 0.018	Secondary atom site location: difference Fourier map
wR(F^2) = 0.042	w = 1/[σ^2(Fo^2) + (0.0132P)^2 + 9.8432P] where P = (Fo^2 + 2Fc^2)/3
S = 1.18	(Δ/σ)max < 0.001
324 reflections	Δρmax = 0.72 e Å^−3
20 parameters	Δρmin = −1.08 e Å^−3

Special details

Experimental. Data collection is performed with four batch runs at ϕ = 0.00 ° (456 frames), at ϕ = 90.00 ° (456 frames), at ϕ = 180.00 ° (230 frames), and at ϕ = 270.00 (230 frames). Frame width = 0.40 \& in ω. Data is merged, corrected for decay, and treated with multi-scan absorption corrections.

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)
Ge1	0.0000	0.30101 (5)	0.11557 (5)	0.00715 (15)	0.94
In1	0.0000	0.30101 (5)	0.11557 (5)	0.00715 (15)	0.06
Ge2	0.18368 (3)	0.18368 (3)	0.18368 (3)	0.00719 (16)	0.91
In2	0.18368 (3)	0.18368 (3)	0.18368 (3)	0.00719 (16)	0.09
In3	0.2500	0.0000	0.5000	0.00946 (19)
Rb1	0.2500	0.5000	0.0000	0.0184 (3)
Eu2	0.0000	0.0000	0.0000	0.0110 (3)	0.30
Rb2	0.0000	0.0000	0.0000	0.0110 (3)	0.70

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ge1	0.0074 (3)	0.0069 (3)	0.0071 (3)	0.000	0.000	−0.0003 (2)
In1	0.0074 (3)	0.0069 (3)	0.0071 (3)	0.000	0.000	−0.0003 (2)
Ge2	0.00719 (16)	0.00719 (16)	0.00719 (16)	−0.00043 (13)	−0.00043 (13)	−0.00043 (13)
In2	0.00719 (16)	0.00719 (16)	0.00719 (16)	−0.00043 (13)	−0.00043 (13)	−0.00043 (13)
In3	0.0104 (4)	0.0090 (3)	0.0090 (3)	0.000	0.000	0.000
Rb1	0.0118 (5)	0.0217 (4)	0.0217 (4)	0.000	0.000	0.000
Eu2	0.0110 (3)	0.0110 (3)	0.0110 (3)	0.000	0.000	0.000
Rb2	0.0110 (3)	0.0110 (3)	0.0110 (3)	0.000	0.000	0.000

Geometric parameters (Å, º)

Ge1—Ge2	2.5185 (4)	In3—Rb1^x	3.8994 (3)
Ge1—In2^i	2.5185 (4)	In3—Rb1^xi	3.8994 (3)
Ge1—Ge2^i	2.5185 (4)	In3—Rb1^v	3.8994 (3)
Ge1—In1^ii	2.5492 (12)	In3—Rb1^iii	3.8994 (3)
Ge1—Ge1^ii	2.5492 (12)	Rb1—In1^xii	3.7475 (5)
Ge1—In3^iii	2.6486 (6)	Rb1—In1^ii	3.7475 (5)
Ge1—Eu2	3.5562 (7)	Rb1—Ge1^xii	3.7475 (5)
Ge1—Rb1	3.7475 (5)	Rb1—Ge1^ii	3.7475 (5)
Ge1—Rb1^iv	3.7475 (5)	Rb1—In1^xiii	3.7475 (5)
Ge2—In1^iii	2.5185 (4)	Rb1—Ge1^xiii	3.7475 (5)
Ge2—In1^v	2.5185 (4)	Rb1—Ge1^iv	3.7475 (5)
Ge2—Ge1^iii	2.5185 (4)	Rb1—In1^xiv	3.7475 (5)
Ge2—Ge1^v	2.5185 (4)	Rb1—In1^iv	3.7475 (5)
Ge2—In2^vi	2.5340 (13)	Rb1—Ge1^xiv	3.7475 (5)
Ge2—Ge2^vi	2.5340 (13)	Rb1—In1^xv	3.7475 (5)
Ge2—Eu2	3.5088 (7)	Rb1—Ge1^xvi	3.7475 (5)
Ge2—Rb1^iii	4.1001 (4)	Eu2—In2^xvii	3.5088 (7)
Ge2—Rb1	4.1001 (4)	Eu2—Ge2^xvii	3.5088 (7)
In3—In1^vii	2.6486 (6)	Eu2—In2^i	3.5088 (7)
In3—Ge1^v	2.6486 (6)	Eu2—In2^xviii	3.5088 (7)
In3—In1^v	2.6486 (6)	Eu2—In2^xix	3.5088 (7)
In3—Ge1^vii	2.6486 (6)	Eu2—In2^xx	3.5088 (7)
In3—In1^viii	2.6486 (6)	Eu2—In2^ii	3.5088 (7)
In3—Ge1^viii	2.6486 (6)	Eu2—In2^xxi	3.5088 (7)
In3—In1^ix	2.6486 (6)	Eu2—Ge2^i	3.5088 (7)
In3—Ge1^ix	2.6486 (6)	Eu2—Ge2^xviii	3.5088 (7)
Ge2—Ge1—In2^i	107.10 (3)	Rb1^xi—In3—Rb1^v	90.0
Ge2—Ge1—Ge2^i	107.10 (3)	In1^vii—In3—Rb1^iii	66.681 (8)
Ge2—Ge1—In1^ii	107.354 (15)	Ge1^v—In3—Rb1^iii	79.043 (12)
In2^i—Ge1—In1^ii	107.354 (15)	In1^v—In3—Rb1^iii	79.043 (12)
Ge2^i—Ge1—In1^ii	107.354 (15)	Ge1^vii—In3—Rb1^iii	66.681 (8)
Ge2—Ge1—Ge1^ii	107.354 (15)	In1^viii—In3—Rb1^iii	66.681 (8)
In2^i—Ge1—Ge1^ii	107.354 (15)	Ge1^viii—In3—Rb1^iii	66.681 (8)
Ge2^i—Ge1—Ge1^ii	107.354 (15)	In1^ix—In3—Rb1^iii	169.043 (12)
Ge2—Ge1—In3^iii	105.00 (2)	Ge1^ix—In3—Rb1^iii	169.043 (12)
In2^i—Ge1—In3^iii	105.00 (2)	Rb1^x—In3—Rb1^iii	90.0
Ge2^i—Ge1—In3^iii	105.00 (2)	Rb1^xi—In3—Rb1^iii	120.0
In1^ii—Ge1—In3^iii	124.042 (12)	Rb1^v—In3—Rb1^iii	120.0
Ge1^ii—Ge1—In3^iii	124.042 (12)	In1^xii—Rb1—In1^ii	160.003 (18)
Ge2—Ge1—Eu2	68.112 (19)	In1^ii—Rb1—Ge1^xii	160.003 (18)
In2^i—Ge1—Eu2	68.113 (19)	In1^xii—Rb1—Ge1^ii	160.003 (18)
Ge2^i—Ge1—Eu2	68.113 (19)	Ge1^xii—Rb1—Ge1^ii	160.003 (18)
In1^ii—Ge1—Eu2	68.997 (9)	In1^xii—Rb1—In1^xiii	39.767 (17)
Ge1^ii—Ge1—Eu2	68.997 (9)	In1^ii—Rb1—In1^xiii	122.776 (7)
In3^iii—Ge1—Eu2	166.96 (2)	Ge1^xii—Rb1—In1^xiii	39.767 (17)
Ge2—Ge1—Rb1	79.079 (9)	Ge1^ii—Rb1—In1^xiii	122.776 (7)
In2^i—Ge1—Rb1	173.823 (18)	In1^xii—Rb1—Ge1^xiii	39.767 (17)
Ge2^i—Ge1—Rb1	173.823 (18)	In1^ii—Rb1—Ge1^xiii	122.776 (7)
In1^ii—Ge1—Rb1	70.116 (8)	Ge1^xii—Rb1—Ge1^xiii	39.767 (17)
Ge1^ii—Ge1—Rb1	70.116 (8)	Ge1^ii—Rb1—Ge1^xiii	122.776 (7)
In3^iii—Ge1—Rb1	72.850 (10)	In1^xii—Rb1—Ge1^iv	122.776 (7)
Eu2—Ge1—Rb1	115.140 (11)	In1^ii—Rb1—Ge1^iv	71.697 (15)
Ge2—Ge1—Rb1^iv	173.823 (18)	Ge1^xii—Rb1—Ge1^iv	122.776 (7)
In2^i—Ge1—Rb1^iv	79.079 (9)	Ge1^ii—Rb1—Ge1^iv	71.697 (15)
Ge2^i—Ge1—Rb1^iv	79.079 (9)	In1^xiii—Rb1—Ge1^iv	160.003 (18)
In1^ii—Ge1—Rb1^iv	70.116 (8)	Ge1^xiii—Rb1—Ge1^iv	160.003 (18)
Ge1^ii—Ge1—Rb1^iv	70.116 (8)	In1^xii—Rb1—In1^xiv	71.697 (15)
In3^iii—Ge1—Rb1^iv	72.850 (10)	In1^ii—Rb1—In1^xiv	122.776 (7)
Eu2—Ge1—Rb1^iv	115.140 (11)	Ge1^xii—Rb1—In1^xiv	71.697 (15)
Rb1—Ge1—Rb1^iv	94.744 (13)	Ge1^ii—Rb1—In1^xiv	122.776 (7)
Ge1—Ge2—In1^iii	109.07 (2)	In1^xiii—Rb1—In1^xiv	85.256 (13)
Ge1—Ge2—In1^v	109.07 (2)	Ge1^xiii—Rb1—In1^xiv	85.256 (13)
In1^iii—Ge2—In1^v	109.07 (2)	Ge1^iv—Rb1—In1^xiv	98.221 (13)
Ge1—Ge2—Ge1^iii	109.07 (2)	In1^xii—Rb1—In1^iv	122.776 (7)
In1^v—Ge2—Ge1^iii	109.07 (2)	In1^ii—Rb1—In1^iv	71.697 (15)
Ge1—Ge2—Ge1^v	109.07 (2)	Ge1^xii—Rb1—In1^iv	122.776 (7)
In1^iii—Ge2—Ge1^v	109.07 (2)	Ge1^ii—Rb1—In1^iv	71.697 (15)
Ge1^iii—Ge2—Ge1^v	109.07 (2)	In1^xiii—Rb1—In1^iv	160.003 (18)
Ge1—Ge2—In2^vi	109.874 (19)	Ge1^xiii—Rb1—In1^iv	160.003 (18)
In1^iii—Ge2—In2^vi	109.874 (19)	In1^xiv—Rb1—In1^iv	98.221 (13)
In1^v—Ge2—In2^vi	109.874 (19)	In1^xii—Rb1—Ge1^xiv	71.697 (15)
Ge1^iii—Ge2—In2^vi	109.874 (19)	In1^ii—Rb1—Ge1^xiv	122.776 (7)
Ge1^v—Ge2—In2^vi	109.874 (19)	Ge1^xii—Rb1—Ge1^xiv	71.697 (15)
Ge1—Ge2—Ge2^vi	109.874 (19)	Ge1^ii—Rb1—Ge1^xiv	122.776 (7)
In1^iii—Ge2—Ge2^vi	109.874 (19)	In1^xiii—Rb1—Ge1^xiv	85.256 (13)
In1^v—Ge2—Ge2^vi	109.874 (19)	Ge1^xiii—Rb1—Ge1^xiv	85.256 (13)
Ge1^iii—Ge2—Ge2^vi	109.874 (19)	Ge1^iv—Rb1—Ge1^xiv	98.221 (13)
Ge1^v—Ge2—Ge2^vi	109.874 (19)	In1^iv—Rb1—Ge1^xiv	98.221 (13)
Ge1—Ge2—Eu2	70.126 (19)	In1^xii—Rb1—In1^xv	85.256 (13)
In1^iii—Ge2—Eu2	70.126 (19)	In1^ii—Rb1—In1^xv	98.221 (13)
In1^v—Ge2—Eu2	70.126 (19)	Ge1^xii—Rb1—In1^xv	85.256 (13)
Ge1^iii—Ge2—Eu2	70.126 (19)	Ge1^ii—Rb1—In1^xv	98.221 (13)
Ge1^v—Ge2—Eu2	70.126 (19)	In1^xiii—Rb1—In1^xv	71.697 (15)
In2^vi—Ge2—Eu2	180.00 (4)	Ge1^xiii—Rb1—In1^xv	71.697 (15)
Ge2^vi—Ge2—Eu2	180.00 (4)	Ge1^iv—Rb1—In1^xv	122.776 (7)
Ge1—Ge2—Rb1^iii	172.541 (13)	In1^xiv—Rb1—In1^xv	39.767 (17)
In1^iii—Ge2—Rb1^iii	63.826 (11)	In1^iv—Rb1—In1^xv	122.776 (7)
In1^v—Ge2—Rb1^iii	76.392 (13)	Ge1^xiv—Rb1—In1^xv	39.767 (17)
Ge1^iii—Ge2—Rb1^iii	63.826 (11)	In1^xii—Rb1—Ge1^xvi	98.221 (13)
Ge1^v—Ge2—Rb1^iii	76.392 (13)	In1^ii—Rb1—Ge1^xvi	85.256 (13)
In2^vi—Ge2—Rb1^iii	72.000 (9)	Ge1^xii—Rb1—Ge1^xvi	98.221 (13)
Ge2^vi—Ge2—Rb1^iii	72.000 (9)	Ge1^ii—Rb1—Ge1^xvi	85.256 (13)
Eu2—Ge2—Rb1^iii	108.000 (9)	In1^xiii—Rb1—Ge1^xvi	122.776 (7)
Ge1—Ge2—Rb1	63.826 (11)	Ge1^xiii—Rb1—Ge1^xvi	122.776 (7)
In1^iii—Ge2—Rb1	76.392 (13)	Ge1^iv—Rb1—Ge1^xvi	39.767 (17)
In1^v—Ge2—Rb1	172.541 (13)	In1^xiv—Rb1—Ge1^xvi	122.776 (7)
Ge1^iii—Ge2—Rb1	76.392 (13)	In1^iv—Rb1—Ge1^xvi	39.767 (17)
Ge1^v—Ge2—Rb1	172.541 (13)	Ge1^xiv—Rb1—Ge1^xvi	122.776 (7)
In2^vi—Ge2—Rb1	72.000 (9)	In1^xv—Rb1—Ge1^xvi	160.003 (18)
Ge2^vi—Ge2—Rb1	72.000 (9)	Ge2—Eu2—In2^xvii	180.000 (10)
Eu2—Ge2—Rb1	108.000 (9)	Ge2—Eu2—Ge2^xvii	180.000 (10)
Rb1^iii—Ge2—Rb1	110.901 (8)	Ge2—Eu2—In2^i	70.5
In1^vii—In3—Ge1^v	108.264 (12)	In2^xvii—Eu2—In2^i	109.5
In1^vii—In3—In1^v	108.264 (12)	Ge2^xvii—Eu2—In2^i	109.5
Ge1^v—In3—Ge1^vii	108.264 (12)	Ge2—Eu2—In2^xviii	109.5
In1^v—In3—Ge1^vii	108.264 (12)	In2^xvii—Eu2—In2^xviii	70.5
In1^vii—In3—In1^viii	111.91 (2)	Ge2^xvii—Eu2—In2^xviii	70.5
Ge1^v—In3—In1^viii	108.264 (12)	In2^i—Eu2—In2^xviii	180.0
In1^v—In3—In1^viii	108.264 (12)	Ge2—Eu2—In2^xix	70.529 (1)
Ge1^vii—In3—In1^viii	111.91 (2)	In2^xvii—Eu2—In2^xix	109.5
In1^vii—In3—Ge1^viii	111.91 (2)	Ge2^xvii—Eu2—In2^xix	109.5
Ge1^v—In3—Ge1^viii	108.264 (12)	In2^i—Eu2—In2^xix	109.5
In1^v—In3—Ge1^viii	108.264 (12)	In2^xviii—Eu2—In2^xix	70.5
Ge1^vii—In3—Ge1^viii	111.91 (2)	Ge2—Eu2—In2^xx	109.5
In1^vii—In3—In1^ix	108.264 (12)	In2^xvii—Eu2—In2^xx	70.529 (1)
Ge1^v—In3—In1^ix	111.91 (2)	Ge2^xvii—Eu2—In2^xx	70.529 (1)
In1^v—In3—In1^ix	111.91 (2)	In2^i—Eu2—In2^xx	70.5
Ge1^vii—In3—In1^ix	108.264 (12)	In2^xviii—Eu2—In2^xx	109.5
In1^viii—In3—In1^ix	108.264 (12)	In2^xix—Eu2—In2^xx	180.0
Ge1^viii—In3—In1^ix	108.264 (12)	Ge2—Eu2—In2^ii	70.5
In1^vii—In3—Ge1^ix	108.264 (12)	In2^xvii—Eu2—In2^ii	109.5
Ge1^v—In3—Ge1^ix	111.91 (2)	Ge2^xvii—Eu2—In2^ii	109.5
In1^v—In3—Ge1^ix	111.91 (2)	In2^i—Eu2—In2^ii	109.5
Ge1^vii—In3—Ge1^ix	108.264 (12)	In2^xviii—Eu2—In2^ii	70.5
In1^viii—In3—Ge1^ix	108.264 (12)	In2^xix—Eu2—In2^ii	109.5
Ge1^viii—In3—Ge1^ix	108.264 (12)	In2^xx—Eu2—In2^ii	70.5
In1^vii—In3—Rb1^x	66.681 (8)	Ge2—Eu2—In2^xxi	109.5
Ge1^v—In3—Rb1^x	169.043 (12)	In2^xvii—Eu2—In2^xxi	70.5
In1^v—In3—Rb1^x	169.043 (12)	Ge2^xvii—Eu2—In2^xxi	70.5
Ge1^vii—In3—Rb1^x	66.681 (8)	In2^i—Eu2—In2^xxi	70.5
In1^viii—In3—Rb1^x	66.681 (8)	In2^xviii—Eu2—In2^xxi	109.5
Ge1^viii—In3—Rb1^x	66.681 (8)	In2^xix—Eu2—In2^xxi	70.5
In1^ix—In3—Rb1^x	79.043 (12)	In2^xx—Eu2—In2^xxi	109.5
Ge1^ix—In3—Rb1^x	79.043 (12)	In2^ii—Eu2—In2^xxi	180.000 (10)
In1^vii—In3—Rb1^xi	169.043 (12)	Ge2—Eu2—Ge2^i	70.5
Ge1^v—In3—Rb1^xi	66.681 (8)	In2^xvii—Eu2—Ge2^i	109.5
In1^v—In3—Rb1^xi	66.681 (8)	Ge2^xvii—Eu2—Ge2^i	109.5
Ge1^vii—In3—Rb1^xi	169.043 (12)	In2^xviii—Eu2—Ge2^i	180.0
In1^viii—In3—Rb1^xi	79.043 (12)	In2^xix—Eu2—Ge2^i	109.5
Ge1^viii—In3—Rb1^xi	79.043 (12)	In2^xx—Eu2—Ge2^i	70.5
In1^ix—In3—Rb1^xi	66.681 (8)	In2^ii—Eu2—Ge2^i	109.5
Ge1^ix—In3—Rb1^xi	66.681 (8)	In2^xxi—Eu2—Ge2^i	70.5
Rb1^x—In3—Rb1^xi	120.0	Ge2—Eu2—Ge2^xviii	109.5
In1^vii—In3—Rb1^v	79.043 (12)	In2^xvii—Eu2—Ge2^xviii	70.5
Ge1^v—In3—Rb1^v	66.681 (8)	Ge2^xvii—Eu2—Ge2^xviii	70.5
In1^v—In3—Rb1^v	66.681 (8)	In2^i—Eu2—Ge2^xviii	180.0
Ge1^vii—In3—Rb1^v	79.043 (12)	In2^xix—Eu2—Ge2^xviii	70.5
In1^viii—In3—Rb1^v	169.043 (12)	In2^xx—Eu2—Ge2^xviii	109.5
Ge1^viii—In3—Rb1^v	169.043 (12)	In2^ii—Eu2—Ge2^xviii	70.5
In1^ix—In3—Rb1^v	66.681 (8)	In2^xxi—Eu2—Ge2^xviii	109.5
Ge1^ix—In3—Rb1^v	66.681 (8)	Ge2^i—Eu2—Ge2^xviii	180.0
Rb1^x—In3—Rb1^v	120.0

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

(II) Hexarubidium dieuropium decaindium hexatriacontagermanide

Crystal data

Rb6.30Eu1.70In9.76Ge36.24	Dx = 5.584 Mg m^−3
Mr = 4548.10	Mo Kα radiation, λ = 0.71073 Å
Cubic, Pm3n	Cell parameters from 1018 reflections
Hall symbol: -P 4n 2 3	θ = 2.6–26.9°
a = 11.0592 (3) Å	µ = 31.41 mm^−1
V = 1352.61 (6) Å^3	T = 200 K
Z = 1	Irregular, silver–grey
F(000) = 1978	0.08 × 0.06 × 0.05 mm

Data collection

Bruker SMART APEX CCD diffractometer	324 independent reflections
Radiation source: fine-focus sealed tube	295 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.065
ω and ϕ scans	θmax = 28.0°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 2008)	h = −14→14
Tmin = 0.199, Tmax = 0.277	k = −14→14
16518 measured reflections	l = −14→14

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)] = 0.016	Secondary atom site location: difference Fourier map
wR(F^2) = 0.031	w = 1/[σ^2(Fo^2) + (0.008P)^2 + 6.2731P] where P = (Fo^2 + 2Fc^2)/3
S = 1.15	(Δ/σ)max < 0.001
324 reflections	Δρmax = 0.43 e Å^−3
20 parameters	Δρmin = −0.71 e Å^−3

Special details

Experimental. Data collection is performed with four batch runs at ϕ = 0.00 ° (456 frames), at ϕ = 90.00 ° (456 frames), at ϕ = 180.00 ° (230 frames), and at ϕ = 270.00 (230 frames). Frame width = 0.40 \& in ω. Data is merged, corrected for decay, and treated with multi-scan absorption corrections.

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)
Ge1	0.0000	0.30045 (5)	0.11392 (5)	0.00995 (12)	0.97
In1	0.0000	0.30045 (5)	0.11392 (5)	0.00995 (12)	0.03
Ge2	0.18311 (3)	0.18311 (3)	0.18311 (3)	0.00920 (13)	0.81
In2	0.18311 (3)	0.18311 (3)	0.18311 (3)	0.00920 (13)	0.19
In3	0.2500	0.0000	0.5000	0.00946 (15)
Rb1	0.2500	0.5000	0.0000	0.0203 (2)
Eu2	0.0000	0.0000	0.0000	0.0146 (2)	0.85
Rb2	0.0000	0.0000	0.0000	0.0146 (2)	0.15

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ge1	0.0116 (3)	0.0091 (2)	0.0091 (2)	0.000	0.000	−0.0011 (2)
In1	0.0116 (3)	0.0091 (2)	0.0091 (2)	0.000	0.000	−0.0011 (2)
Ge2	0.00920 (13)	0.00920 (13)	0.00920 (13)	0.00006 (12)	0.00006 (12)	0.00006 (12)
In2	0.00920 (13)	0.00920 (13)	0.00920 (13)	0.00006 (12)	0.00006 (12)	0.00006 (12)
In3	0.0103 (3)	0.0091 (2)	0.0091 (2)	0.000	0.000	0.000
Rb1	0.0139 (5)	0.0234 (4)	0.0234 (4)	0.000	0.000	0.000
Eu2	0.0146 (2)	0.0146 (2)	0.0146 (2)	0.000	0.000	0.000
Rb2	0.0146 (2)	0.0146 (2)	0.0146 (2)	0.000	0.000	0.000

Geometric parameters (Å, º)

Ge1—In1^i	2.5198 (10)	In3—Rb1^xi	3.9100 (1)
Ge1—Ge1^i	2.5198 (10)	In3—Rb1^v	3.9100 (1)
Ge1—In2^ii	2.5239 (4)	In3—Rb1^iii	3.9100 (1)
Ge1—Ge2^ii	2.5239 (4)	Rb1—In1^xii	3.7552 (4)
Ge1—Ge2	2.5239 (4)	Rb1—In1^i	3.7552 (4)
Ge1—In3^iii	2.6712 (5)	Rb1—Ge1^xii	3.7552 (4)
Ge1—Eu2	3.5536 (5)	Rb1—Ge1^i	3.7552 (4)
Ge1—Rb1	3.7552 (4)	Rb1—In1^xiii	3.7552 (4)
Ge1—Rb1^iv	3.7552 (4)	Rb1—Ge1^xiii	3.7552 (4)
Ge2—In1^iii	2.5239 (4)	Rb1—Ge1^iv	3.7552 (4)
Ge2—In1^v	2.5239 (4)	Rb1—In1^xiv	3.7552 (4)
Ge2—Ge1^iii	2.5239 (4)	Rb1—In1^iv	3.7552 (4)
Ge2—Ge1^v	2.5239 (4)	Rb1—Ge1^xiv	3.7552 (4)
Ge2—In2^vi	2.5627 (11)	Rb1—In1^xv	3.7552 (4)
Ge2—Ge2^vi	2.5627 (11)	Rb1—Ge1^xvi	3.7552 (4)
Ge2—Eu2	3.5074 (6)	Eu2—In2^xvii	3.5074 (6)
Ge2—Rb1^iii	4.1146 (2)	Eu2—Ge2^xvii	3.5074 (6)
Ge2—Rb1	4.1146 (2)	Eu2—In2^ii	3.5074 (6)
In3—In1^vii	2.6711 (5)	Eu2—In2^xviii	3.5074 (6)
In3—Ge1^v	2.6711 (5)	Eu2—In2^xix	3.5074 (6)
In3—In1^v	2.6711 (5)	Eu2—In2^xx	3.5074 (6)
In3—Ge1^vii	2.6711 (5)	Eu2—In2^i	3.5074 (6)
In3—In1^viii	2.6711 (5)	Eu2—In2^xxi	3.5074 (6)
In3—Ge1^viii	2.6711 (5)	Eu2—Ge2^ii	3.5074 (6)
In3—In1^ix	2.6711 (5)	Eu2—Ge2^xviii	3.5074 (6)
In3—Ge1^ix	2.6711 (5)	Eu2—Ge2^xix	3.5074 (6)
In3—Rb1^x	3.9100 (1)	Eu2—Ge2^xx	3.5074 (6)
In1^i—Ge1—In2^ii	107.647 (13)	Ge1^vii—In3—Rb1^iii	66.523 (7)
Ge1^i—Ge1—In2^ii	107.647 (13)	In1^viii—In3—Rb1^iii	66.523 (7)
In1^i—Ge1—Ge2^ii	107.647 (13)	Ge1^viii—In3—Rb1^iii	66.523 (7)
Ge1^i—Ge1—Ge2^ii	107.647 (13)	In1^ix—In3—Rb1^iii	169.291 (11)
In1^i—Ge1—Ge2	107.648 (13)	Ge1^ix—In3—Rb1^iii	169.291 (11)
Ge1^i—Ge1—Ge2	107.648 (13)	Rb1^x—In3—Rb1^iii	90.0
In2^ii—Ge1—Ge2	106.71 (2)	Rb1^xi—In3—Rb1^iii	120.0
Ge2^ii—Ge1—Ge2	106.71 (2)	Rb1^v—In3—Rb1^iii	120.0
In1^i—Ge1—In3^iii	124.291 (11)	In1^xii—Rb1—In1^i	159.458 (16)
Ge1^i—Ge1—In3^iii	124.291 (11)	In1^i—Rb1—Ge1^xii	159.458 (16)
In2^ii—Ge1—In3^iii	104.715 (18)	In1^xii—Rb1—Ge1^i	159.458 (16)
Ge2^ii—Ge1—In3^iii	104.715 (18)	Ge1^xii—Rb1—Ge1^i	159.458 (16)
Ge2—Ge1—In3^iii	104.714 (18)	In1^xii—Rb1—In1^xiii	39.207 (15)
In1^i—Ge1—Eu2	69.236 (8)	In1^i—Rb1—In1^xiii	122.825 (7)
Ge1^i—Ge1—Eu2	69.236 (8)	Ge1^xii—Rb1—In1^xiii	39.207 (15)
In2^ii—Ge1—Eu2	68.081 (17)	Ge1^i—Rb1—In1^xiii	122.825 (7)
Ge2^ii—Ge1—Eu2	68.081 (17)	In1^xii—Rb1—Ge1^xiii	39.207 (15)
Ge2—Ge1—Eu2	68.081 (17)	In1^i—Rb1—Ge1^xiii	122.825 (7)
In3^iii—Ge1—Eu2	166.474 (19)	Ge1^xii—Rb1—Ge1^xiii	39.207 (15)
In1^i—Ge1—Rb1	70.397 (8)	Ge1^i—Rb1—Ge1^xiii	122.825 (7)
Ge1^i—Ge1—Rb1	70.397 (8)	In1^xii—Rb1—Ge1^iv	122.825 (7)
In2^ii—Ge1—Rb1	174.039 (17)	In1^i—Rb1—Ge1^iv	71.984 (13)
Ge2^ii—Ge1—Rb1	174.039 (17)	Ge1^xii—Rb1—Ge1^iv	122.825 (7)
Ge2—Ge1—Rb1	79.231 (8)	Ge1^i—Rb1—Ge1^iv	71.984 (13)
In3^iii—Ge1—Rb1	72.752 (9)	In1^xiii—Rb1—Ge1^iv	159.457 (16)
Eu2—Ge1—Rb1	115.503 (10)	Ge1^xiii—Rb1—Ge1^iv	159.457 (16)
In1^i—Ge1—Rb1^iv	70.397 (8)	In1^xii—Rb1—In1^xiv	71.984 (13)
Ge1^i—Ge1—Rb1^iv	70.397 (8)	In1^i—Rb1—In1^xiv	122.825 (7)
In2^ii—Ge1—Rb1^iv	79.232 (8)	Ge1^xii—Rb1—In1^xiv	71.984 (13)
Ge2^ii—Ge1—Rb1^iv	79.232 (8)	Ge1^i—Rb1—In1^xiv	122.825 (7)
Ge2—Ge1—Rb1^iv	174.039 (17)	In1^xiii—Rb1—In1^xiv	85.173 (11)
In3^iii—Ge1—Rb1^iv	72.752 (9)	Ge1^xiii—Rb1—In1^xiv	85.173 (11)
Eu2—Ge1—Rb1^iv	115.503 (10)	Ge1^iv—Rb1—In1^xiv	98.496 (12)
Rb1—Ge1—Rb1^iv	94.827 (11)	In1^xii—Rb1—In1^iv	122.825 (7)
Ge1—Ge2—In1^iii	108.976 (17)	In1^i—Rb1—In1^iv	71.984 (13)
Ge1—Ge2—In1^v	108.977 (17)	Ge1^xii—Rb1—In1^iv	122.825 (7)
In1^iii—Ge2—In1^v	108.977 (17)	Ge1^i—Rb1—In1^iv	71.984 (13)
Ge1—Ge2—Ge1^iii	108.976 (17)	In1^xiii—Rb1—In1^iv	159.457 (16)
In1^v—Ge2—Ge1^iii	108.977 (17)	Ge1^xiii—Rb1—In1^iv	159.457 (16)
Ge1—Ge2—Ge1^v	108.977 (17)	In1^xiv—Rb1—In1^iv	98.496 (12)
In1^iii—Ge2—Ge1^v	108.977 (17)	In1^xii—Rb1—Ge1^xiv	71.984 (13)
Ge1^iii—Ge2—Ge1^v	108.977 (17)	In1^i—Rb1—Ge1^xiv	122.825 (7)
Ge1—Ge2—In2^vi	109.962 (17)	Ge1^xii—Rb1—Ge1^xiv	71.984 (13)
In1^iii—Ge2—In2^vi	109.961 (16)	Ge1^i—Rb1—Ge1^xiv	122.825 (7)
In1^v—Ge2—In2^vi	109.961 (17)	In1^xiii—Rb1—Ge1^xiv	85.173 (11)
Ge1^iii—Ge2—In2^vi	109.961 (16)	Ge1^xiii—Rb1—Ge1^xiv	85.173 (11)
Ge1^v—Ge2—In2^vi	109.961 (17)	Ge1^iv—Rb1—Ge1^xiv	98.496 (12)
Ge1—Ge2—Ge2^vi	109.962 (17)	In1^iv—Rb1—Ge1^xiv	98.496 (12)
In1^iii—Ge2—Ge2^vi	109.961 (16)	In1^xii—Rb1—In1^xv	85.173 (11)
In1^v—Ge2—Ge2^vi	109.961 (17)	In1^i—Rb1—In1^xv	98.496 (12)
Ge1^iii—Ge2—Ge2^vi	109.961 (16)	Ge1^xii—Rb1—In1^xv	85.173 (11)
Ge1^v—Ge2—Ge2^vi	109.961 (17)	Ge1^i—Rb1—In1^xv	98.496 (12)
Ge1—Ge2—Eu2	70.038 (17)	In1^xiii—Rb1—In1^xv	71.984 (13)
In1^iii—Ge2—Eu2	70.039 (17)	Ge1^xiii—Rb1—In1^xv	71.984 (13)
In1^v—Ge2—Eu2	70.039 (17)	Ge1^iv—Rb1—In1^xv	122.825 (7)
Ge1^iii—Ge2—Eu2	70.039 (17)	In1^xiv—Rb1—In1^xv	39.207 (15)
Ge1^v—Ge2—Eu2	70.039 (17)	In1^iv—Rb1—In1^xv	122.825 (7)
In2^vi—Ge2—Eu2	180.00 (4)	Ge1^xiv—Rb1—In1^xv	39.207 (15)
Ge2^vi—Ge2—Eu2	180.00 (4)	In1^xii—Rb1—Ge1^xvi	98.496 (12)
Ge1—Ge2—Rb1^iii	172.276 (11)	In1^i—Rb1—Ge1^xvi	85.173 (11)
In1^iii—Ge2—Rb1^iii	63.712 (10)	Ge1^xii—Rb1—Ge1^xvi	98.496 (12)
In1^v—Ge2—Rb1^iii	76.755 (11)	Ge1^i—Rb1—Ge1^xvi	85.173 (11)
Ge1^iii—Ge2—Rb1^iii	63.712 (10)	In1^xiii—Rb1—Ge1^xvi	122.825 (7)
Ge1^v—Ge2—Rb1^iii	76.755 (11)	Ge1^xiii—Rb1—Ge1^xvi	122.825 (7)
In2^vi—Ge2—Rb1^iii	71.856 (7)	Ge1^iv—Rb1—Ge1^xvi	39.207 (15)
Ge2^vi—Ge2—Rb1^iii	71.856 (7)	In1^xiv—Rb1—Ge1^xvi	122.825 (7)
Eu2—Ge2—Rb1^iii	108.144 (7)	In1^iv—Rb1—Ge1^xvi	39.207 (15)
Ge1—Ge2—Rb1	63.712 (10)	Ge1^xiv—Rb1—Ge1^xvi	122.825 (7)
In1^iii—Ge2—Rb1	76.755 (11)	In1^xv—Rb1—Ge1^xvi	159.458 (16)
In1^v—Ge2—Rb1	172.277 (11)	In2^xvii—Eu2—In2^ii	109.5
Ge1^iii—Ge2—Rb1	76.755 (11)	Ge2^xvii—Eu2—In2^ii	109.5
Ge1^v—Ge2—Rb1	172.277 (11)	In2^xvii—Eu2—In2^xviii	70.5
In2^vi—Ge2—Rb1	71.856 (7)	Ge2^xvii—Eu2—In2^xviii	70.5
Ge2^vi—Ge2—Rb1	71.856 (7)	In2^ii—Eu2—In2^xviii	180.0
Eu2—Ge2—Rb1	108.144 (7)	In2^xvii—Eu2—In2^xix	109.5
Rb1^iii—Ge2—Rb1	110.765 (7)	Ge2^xvii—Eu2—In2^xix	109.5
In1^vii—In3—Ge1^v	108.507 (11)	In2^ii—Eu2—In2^xix	109.5
In1^vii—In3—In1^v	108.507 (11)	In2^xviii—Eu2—In2^xix	70.5
Ge1^v—In3—Ge1^vii	108.507 (11)	In2^xvii—Eu2—In2^xx	70.529 (1)
In1^v—In3—Ge1^vii	108.507 (11)	Ge2^xvii—Eu2—In2^xx	70.529 (1)
In1^vii—In3—In1^viii	111.42 (2)	In2^ii—Eu2—In2^xx	70.5
Ge1^v—In3—In1^viii	108.507 (11)	In2^xviii—Eu2—In2^xx	109.5
In1^v—In3—In1^viii	108.507 (11)	In2^xix—Eu2—In2^xx	180.0
Ge1^vii—In3—In1^viii	111.42 (2)	In2^xvii—Eu2—In2^i	109.5
In1^vii—In3—Ge1^viii	111.42 (2)	Ge2^xvii—Eu2—In2^i	109.5
Ge1^v—In3—Ge1^viii	108.507 (11)	In2^ii—Eu2—In2^i	109.5
In1^v—In3—Ge1^viii	108.507 (11)	In2^xviii—Eu2—In2^i	70.5
Ge1^vii—In3—Ge1^viii	111.42 (2)	In2^xix—Eu2—In2^i	109.5
In1^vii—In3—In1^ix	108.507 (11)	In2^xx—Eu2—In2^i	70.5
Ge1^v—In3—In1^ix	111.42 (2)	In2^xvii—Eu2—In2^xxi	70.5
In1^v—In3—In1^ix	111.42 (2)	Ge2^xvii—Eu2—In2^xxi	70.5
Ge1^vii—In3—In1^ix	108.507 (11)	In2^ii—Eu2—In2^xxi	70.5
In1^viii—In3—In1^ix	108.507 (11)	In2^xviii—Eu2—In2^xxi	109.5
Ge1^viii—In3—In1^ix	108.507 (11)	In2^xix—Eu2—In2^xxi	70.5
In1^vii—In3—Ge1^ix	108.507 (11)	In2^xx—Eu2—In2^xxi	109.5
Ge1^v—In3—Ge1^ix	111.42 (2)	In2^i—Eu2—In2^xxi	180.000 (9)
In1^v—In3—Ge1^ix	111.42 (2)	In2^xvii—Eu2—Ge2^ii	109.5
Ge1^vii—In3—Ge1^ix	108.507 (11)	Ge2^xvii—Eu2—Ge2^ii	109.5
In1^viii—In3—Ge1^ix	108.507 (11)	In2^xviii—Eu2—Ge2^ii	180.0
Ge1^viii—In3—Ge1^ix	108.507 (11)	In2^xix—Eu2—Ge2^ii	109.5
In1^vii—In3—Rb1^x	66.523 (7)	In2^xx—Eu2—Ge2^ii	70.5
Ge1^v—In3—Rb1^x	169.291 (11)	In2^i—Eu2—Ge2^ii	109.5
In1^v—In3—Rb1^x	169.291 (11)	In2^xxi—Eu2—Ge2^ii	70.5
Ge1^vii—In3—Rb1^x	66.523 (7)	In2^xvii—Eu2—Ge2^xviii	70.5
In1^viii—In3—Rb1^x	66.523 (7)	Ge2^xvii—Eu2—Ge2^xviii	70.5
Ge1^viii—In3—Rb1^x	66.523 (7)	In2^ii—Eu2—Ge2^xviii	180.0
In1^ix—In3—Rb1^x	79.291 (11)	In2^xix—Eu2—Ge2^xviii	70.5
Ge1^ix—In3—Rb1^x	79.291 (11)	In2^xx—Eu2—Ge2^xviii	109.5
In1^vii—In3—Rb1^xi	169.291 (11)	In2^i—Eu2—Ge2^xviii	70.5
Ge1^v—In3—Rb1^xi	66.523 (7)	In2^xxi—Eu2—Ge2^xviii	109.5
In1^v—In3—Rb1^xi	66.523 (7)	Ge2^ii—Eu2—Ge2^xviii	180.0
Ge1^vii—In3—Rb1^xi	169.291 (11)	In2^xvii—Eu2—Ge2^xix	109.5
In1^viii—In3—Rb1^xi	79.291 (11)	Ge2^xvii—Eu2—Ge2^xix	109.5
Ge1^viii—In3—Rb1^xi	79.291 (11)	In2^ii—Eu2—Ge2^xix	109.5
In1^ix—In3—Rb1^xi	66.523 (7)	In2^xviii—Eu2—Ge2^xix	70.5
Ge1^ix—In3—Rb1^xi	66.523 (7)	In2^xx—Eu2—Ge2^xix	180.000 (9)
Rb1^x—In3—Rb1^xi	120.0	In2^i—Eu2—Ge2^xix	109.5
In1^vii—In3—Rb1^v	79.291 (11)	In2^xxi—Eu2—Ge2^xix	70.5
Ge1^v—In3—Rb1^v	66.523 (7)	Ge2^ii—Eu2—Ge2^xix	109.5
In1^v—In3—Rb1^v	66.523 (7)	Ge2^xviii—Eu2—Ge2^xix	70.5
Ge1^vii—In3—Rb1^v	79.291 (11)	In2^xvii—Eu2—Ge2^xx	70.529 (1)
In1^viii—In3—Rb1^v	169.291 (11)	Ge2^xvii—Eu2—Ge2^xx	70.529 (1)
Ge1^viii—In3—Rb1^v	169.291 (11)	In2^ii—Eu2—Ge2^xx	70.5
In1^ix—In3—Rb1^v	66.523 (7)	In2^xviii—Eu2—Ge2^xx	109.5
Ge1^ix—In3—Rb1^v	66.523 (7)	In2^xix—Eu2—Ge2^xx	180.0
Rb1^x—In3—Rb1^v	120.0	In2^i—Eu2—Ge2^xx	70.5
Rb1^xi—In3—Rb1^v	90.0	In2^xxi—Eu2—Ge2^xx	109.5
In1^vii—In3—Rb1^iii	66.523 (7)	Ge2^ii—Eu2—Ge2^xx	70.5
Ge1^v—In3—Rb1^iii	79.291 (11)	Ge2^xviii—Eu2—Ge2^xx	109.5
In1^v—In3—Rb1^iii	79.291 (11)	Ge2^xix—Eu2—Ge2^xx	180.0

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

(III) Hexarubidium dieuropium decaindium hexatriacontagermanide

Crystal data

Rb6.24Eu1.76In10.16Ge35.84	Dx = 5.606 Mg m^−3
Mr = 4568.98	Mo Kα radiation, λ = 0.71073 Å
Cubic, Pm3n	Cell parameters from 1027 reflections
Hall symbol: -P 4n 2 3	θ = 4.1–21.8°
a = 11.0614 (7) Å	µ = 31.35 mm^−1
V = 1353.41 (15) Å^3	T = 200 K
Z = 1	Irregular, silver–grey
F(000) = 1986	0.05 × 0.04 × 0.04 mm

Data collection

Bruker SMART APEX CCD diffractometer	324 independent reflections
Radiation source: fine-focus sealed tube	272 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.107
ω and ϕ scans	θmax = 28.0°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 2008)	h = −14→14
Tmin = 0.327, Tmax = 0.374	k = −14→14
16786 measured reflections	l = −14→14

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)] = 0.021	Secondary atom site location: difference Fourier map
wR(F^2) = 0.044	w = 1/[σ^2(Fo^2) + (0.0126P)^2 + 9.9713P] where P = (Fo^2 + 2Fc^2)/3
S = 1.11	(Δ/σ)max < 0.001
324 reflections	Δρmax = 0.75 e Å^−3
20 parameters	Δρmin = −1.07 e Å^−3

Special details

Experimental. Data collection is performed with four batch runs at ϕ = 0.00 ° (456 frames), at ϕ = 90.00 ° (456 frames), at ϕ = 180.00 ° (230 frames), and at ϕ = 270.00 (230 frames). Frame width = 0.40 \& in ω. Data is merged, corrected for decay, and treated with multi-scan absorption corrections.

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)
Ge1	0.0000	0.30048 (6)	0.11409 (6)	0.01085 (18)	0.96
In1	0.0000	0.30048 (6)	0.11409 (6)	0.01085 (18)	0.04
Ge2	0.18321 (4)	0.18321 (4)	0.18321 (4)	0.01075 (18)	0.80
In2	0.18321 (4)	0.18321 (4)	0.18321 (4)	0.01075 (18)	0.20
In3	0.2500	0.0000	0.5000	0.0112 (2)
Rb1	0.2500	0.5000	0.0000	0.0237 (3)
Eu2	0.0000	0.0000	0.0000	0.0182 (3)	0.88
Rb2	0.0000	0.0000	0.0000	0.0182 (3)	0.12

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ge1	0.0121 (4)	0.0104 (3)	0.0101 (3)	0.000	0.000	−0.0011 (3)
In1	0.0121 (4)	0.0104 (3)	0.0101 (3)	0.000	0.000	−0.0011 (3)
Ge2	0.01075 (18)	0.01075 (18)	0.01075 (18)	−0.00027 (16)	−0.00027 (16)	−0.00027 (16)
In2	0.01075 (18)	0.01075 (18)	0.01075 (18)	−0.00027 (16)	−0.00027 (16)	−0.00027 (16)
In3	0.0116 (5)	0.0110 (3)	0.0110 (3)	0.000	0.000	0.000
Rb1	0.0160 (7)	0.0275 (5)	0.0275 (5)	0.000	0.000	0.000
Eu2	0.0182 (3)	0.0182 (3)	0.0182 (3)	0.000	0.000	0.000
Rb2	0.0182 (3)	0.0182 (3)	0.0182 (3)	0.000	0.000	0.000

Geometric parameters (Å, º)

Ge1—In1^i	2.5240 (14)	In3—Rb1^xi	3.9108 (2)
Ge1—Ge1^i	2.5240 (14)	In3—Rb1^v	3.9108 (2)
Ge1—In2^ii	2.5247 (5)	In3—Rb1^iii	3.9108 (2)
Ge1—Ge2^ii	2.5247 (5)	Rb1—In1^xii	3.7564 (5)
Ge1—Ge2	2.5248 (5)	Rb1—In1^i	3.7564 (5)
Ge1—In3^iii	2.6703 (7)	Rb1—Ge1^xii	3.7564 (5)
Ge1—Eu2	3.5553 (8)	Rb1—Ge1^i	3.7564 (5)
Ge1—Rb1^iv	3.7564 (5)	Rb1—In1^xiii	3.7564 (5)
Ge2—In1^iii	2.5248 (5)	Rb1—Ge1^xiii	3.7564 (5)
Ge2—In1^v	2.5248 (5)	Rb1—In1^xiv	3.7564 (5)
Ge2—Ge1^iii	2.5248 (5)	Rb1—In1^iv	3.7564 (5)
Ge2—Ge1^v	2.5248 (5)	Rb1—Ge1^xiv	3.7564 (5)
Ge2—In2^vi	2.5591 (16)	Rb1—Ge1^iv	3.7564 (5)
Ge2—Ge2^vi	2.5591 (16)	Eu2—In2^xv	3.5101 (8)
Ge2—Eu2	3.5102 (8)	Eu2—Ge2^xv	3.5101 (8)
Ge2—Rb1^iii	4.1148 (4)	Eu2—In2^ii	3.5101 (8)
Ge2—Rb1	4.1148 (4)	Eu2—In2^xvi	3.5101 (8)
In3—In1^vii	2.6703 (7)	Eu2—In2^xvii	3.5101 (8)
In3—Ge1^v	2.6703 (7)	Eu2—In2^xviii	3.5101 (8)
In3—In1^v	2.6703 (7)	Eu2—In2^i	3.5101 (8)
In3—Ge1^vii	2.6703 (7)	Eu2—In2^xix	3.5101 (8)
In3—In1^viii	2.6703 (7)	Eu2—Ge2^ii	3.5101 (8)
In3—Ge1^viii	2.6703 (7)	Eu2—Ge2^xvi	3.5101 (8)
In3—In1^ix	2.6703 (7)	Eu2—Ge2^xvii	3.5101 (8)
In3—Ge1^ix	2.6703 (7)	Eu2—Ge2^xviii	3.5101 (8)
In3—Rb1^x	3.9108 (3)
In1^i—Ge1—In2^ii	107.628 (18)	Rb1^x—In3—Rb1^v	120.0
Ge1^i—Ge1—In2^ii	107.628 (18)	Rb1^xi—In3—Rb1^v	90.0
In1^i—Ge1—Ge2^ii	107.628 (18)	In1^vii—In3—Rb1^iii	66.541 (9)
Ge1^i—Ge1—Ge2^ii	107.628 (18)	Ge1^v—In3—Rb1^iii	79.262 (15)
In1^i—Ge1—Ge2	107.628 (18)	In1^v—In3—Rb1^iii	79.262 (15)
Ge1^i—Ge1—Ge2	107.628 (18)	Ge1^vii—In3—Rb1^iii	66.541 (9)
In2^ii—Ge1—Ge2	106.78 (3)	In1^viii—In3—Rb1^iii	66.541 (9)
Ge2^ii—Ge1—Ge2	106.78 (3)	Ge1^viii—In3—Rb1^iii	66.541 (9)
In1^i—Ge1—In3^iii	124.263 (15)	In1^ix—In3—Rb1^iii	169.262 (15)
Ge1^i—Ge1—In3^iii	124.263 (15)	Ge1^ix—In3—Rb1^iii	169.262 (15)
In2^ii—Ge1—In3^iii	104.72 (3)	Rb1^x—In3—Rb1^iii	90.0
Ge2^ii—Ge1—In3^iii	104.72 (3)	Rb1^xi—In3—Rb1^iii	120.0
Ge2—Ge1—In3^iii	104.72 (3)	Rb1^v—In3—Rb1^iii	120.0
In1^i—Ge1—Eu2	69.209 (11)	Ge1—Rb1—In1^xii	122.817 (9)
Ge1^i—Ge1—Eu2	69.209 (11)	Ge1—Rb1—In1^i	39.26 (2)
In2^ii—Ge1—Eu2	68.11 (2)	In1^xii—Rb1—In1^i	159.51 (2)
Ge2^ii—Ge1—Eu2	68.11 (2)	Ge1—Rb1—Ge1^xii	122.817 (9)
Ge2—Ge1—Eu2	68.11 (2)	In1^i—Rb1—Ge1^xii	159.51 (2)
In3^iii—Ge1—Eu2	166.53 (3)	Ge1—Rb1—Ge1^i	39.26 (2)
In1^i—Ge1—Rb1	70.369 (10)	In1^xii—Rb1—Ge1^i	159.51 (2)
Ge1^i—Ge1—Rb1	70.369 (10)	Ge1^xii—Rb1—Ge1^i	159.51 (2)
In2^ii—Ge1—Rb1	174.00 (2)	Ge1—Rb1—In1^xiii	98.464 (16)
Ge2^ii—Ge1—Rb1	174.00 (2)	In1^xii—Rb1—In1^xiii	39.26 (2)
Ge2—Ge1—Rb1	79.203 (10)	In1^i—Rb1—In1^xiii	122.817 (9)
In3^iii—Ge1—Rb1	72.757 (13)	Ge1^xii—Rb1—In1^xiii	39.26 (2)
Eu2—Ge1—Rb1	115.468 (13)	Ge1^i—Rb1—In1^xiii	122.817 (9)
In1^i—Ge1—Rb1^iv	70.369 (10)	Ge1—Rb1—Ge1^xiii	98.464 (16)
Ge1^i—Ge1—Rb1^iv	70.369 (10)	In1^xii—Rb1—Ge1^xiii	39.26 (2)
In2^ii—Ge1—Rb1^iv	79.204 (10)	In1^i—Rb1—Ge1^xiii	122.817 (9)
Ge2^ii—Ge1—Rb1^iv	79.204 (10)	Ge1^xii—Rb1—Ge1^xiii	39.26 (2)
Ge2—Ge1—Rb1^iv	174.00 (2)	Ge1^i—Rb1—Ge1^xiii	122.817 (9)
In3^iii—Ge1—Rb1^iv	72.757 (13)	Ge1—Rb1—In1^xiv	159.51 (2)
Eu2—Ge1—Rb1^iv	115.468 (13)	In1^xii—Rb1—In1^xiv	71.962 (19)
Rb1—Ge1—Rb1^iv	94.813 (16)	In1^i—Rb1—In1^xiv	122.817 (9)
In1^iii—Ge2—In1^v	108.96 (2)	Ge1^xii—Rb1—In1^xiv	71.962 (19)
In1^v—Ge2—Ge1^iii	108.96 (2)	Ge1^i—Rb1—In1^xiv	122.817 (9)
In1^iii—Ge2—Ge1^v	108.96 (2)	In1^xiii—Rb1—In1^xiv	85.187 (16)
Ge1^iii—Ge2—Ge1^v	108.96 (2)	Ge1^xiii—Rb1—In1^xiv	85.187 (16)
In1^iii—Ge2—Ge1	108.96 (2)	Ge1—Rb1—In1^iv	85.187 (16)
In1^v—Ge2—Ge1	108.96 (2)	In1^xii—Rb1—In1^iv	122.817 (9)
Ge1^iii—Ge2—Ge1	108.96 (2)	In1^i—Rb1—In1^iv	71.962 (19)
Ge1^v—Ge2—Ge1	108.96 (2)	Ge1^xii—Rb1—In1^iv	122.817 (9)
In1^iii—Ge2—In2^vi	109.98 (2)	Ge1^i—Rb1—In1^iv	71.962 (19)
In1^v—Ge2—In2^vi	109.98 (2)	In1^xiii—Rb1—In1^iv	159.51 (2)
Ge1^iii—Ge2—In2^vi	109.98 (2)	Ge1^xiii—Rb1—In1^iv	159.51 (2)
Ge1^v—Ge2—In2^vi	109.98 (2)	In1^xiv—Rb1—In1^iv	98.464 (16)
Ge1—Ge2—In2^vi	109.98 (2)	Ge1—Rb1—Ge1^xiv	159.51 (2)
In1^iii—Ge2—Ge2^vi	109.98 (2)	In1^xii—Rb1—Ge1^xiv	71.962 (19)
In1^v—Ge2—Ge2^vi	109.98 (2)	In1^i—Rb1—Ge1^xiv	122.817 (9)
Ge1^iii—Ge2—Ge2^vi	109.98 (2)	Ge1^xii—Rb1—Ge1^xiv	71.962 (19)
Ge1^v—Ge2—Ge2^vi	109.98 (2)	Ge1^i—Rb1—Ge1^xiv	122.817 (9)
Ge1—Ge2—Ge2^vi	109.98 (2)	In1^xiii—Rb1—Ge1^xiv	85.187 (16)
In1^iii—Ge2—Eu2	70.02 (2)	Ge1^xiii—Rb1—Ge1^xiv	85.187 (16)
In1^v—Ge2—Eu2	70.02 (2)	In1^iv—Rb1—Ge1^xiv	98.464 (16)
Ge1^iii—Ge2—Eu2	70.02 (2)	Ge1—Rb1—Ge1^iv	85.187 (16)
Ge1^v—Ge2—Eu2	70.02 (2)	In1^xii—Rb1—Ge1^iv	122.817 (9)
Ge1—Ge2—Eu2	70.02 (2)	In1^i—Rb1—Ge1^iv	71.962 (19)
In2^vi—Ge2—Eu2	180.00 (5)	Ge1^xii—Rb1—Ge1^iv	122.817 (9)
Ge2^vi—Ge2—Eu2	180.00 (5)	Ge1^i—Rb1—Ge1^iv	71.962 (19)
In1^iii—Ge2—Rb1^iii	63.732 (13)	In1^xiii—Rb1—Ge1^iv	159.51 (2)
In1^v—Ge2—Rb1^iii	76.722 (15)	Ge1^xiii—Rb1—Ge1^iv	159.51 (2)
Ge1^iii—Ge2—Rb1^iii	63.732 (13)	In1^xiv—Rb1—Ge1^iv	98.464 (16)
Ge1^v—Ge2—Rb1^iii	76.722 (15)	Ge1^xiv—Rb1—Ge1^iv	98.464 (16)
Ge1—Ge2—Rb1^iii	172.297 (16)	In2^xv—Eu2—In2^ii	109.5
In2^vi—Ge2—Rb1^iii	71.883 (10)	Ge2^xv—Eu2—In2^ii	109.5
Ge2^vi—Ge2—Rb1^iii	71.883 (10)	In2^xv—Eu2—In2^xvi	70.5
Eu2—Ge2—Rb1^iii	108.117 (10)	Ge2^xv—Eu2—In2^xvi	70.5
In1^iii—Ge2—Rb1	76.722 (15)	In2^ii—Eu2—In2^xvi	180.000 (12)
In1^v—Ge2—Rb1	172.297 (16)	In2^xv—Eu2—In2^xvii	109.5
Ge1^iii—Ge2—Rb1	76.722 (15)	Ge2^xv—Eu2—In2^xvii	109.5
Ge1^v—Ge2—Rb1	172.297 (16)	In2^ii—Eu2—In2^xvii	109.5
Ge1—Ge2—Rb1	63.732 (13)	In2^xvi—Eu2—In2^xvii	70.5
In2^vi—Ge2—Rb1	71.883 (10)	In2^xv—Eu2—In2^xviii	70.5
Ge2^vi—Ge2—Rb1	71.883 (10)	Ge2^xv—Eu2—In2^xviii	70.5
Eu2—Ge2—Rb1	108.117 (10)	In2^ii—Eu2—In2^xviii	70.5
Rb1^iii—Ge2—Rb1	110.791 (10)	In2^xvi—Eu2—In2^xviii	109.5
In1^vii—In3—Ge1^v	108.479 (15)	In2^xvii—Eu2—In2^xviii	180.000 (12)
In1^vii—In3—In1^v	108.479 (15)	In2^xv—Eu2—In2^i	109.5
Ge1^v—In3—Ge1^vii	108.479 (15)	Ge2^xv—Eu2—In2^i	109.5
In1^v—In3—Ge1^vii	108.479 (15)	In2^ii—Eu2—In2^i	109.5
In1^vii—In3—In1^viii	111.48 (3)	In2^xvi—Eu2—In2^i	70.5
Ge1^v—In3—In1^viii	108.479 (15)	In2^xvii—Eu2—In2^i	109.5
In1^v—In3—In1^viii	108.479 (15)	In2^xviii—Eu2—In2^i	70.5
Ge1^vii—In3—In1^viii	111.48 (3)	In2^xv—Eu2—In2^xix	70.5
In1^vii—In3—Ge1^viii	111.48 (3)	Ge2^xv—Eu2—In2^xix	70.5
Ge1^v—In3—Ge1^viii	108.479 (15)	In2^ii—Eu2—In2^xix	70.5
In1^v—In3—Ge1^viii	108.479 (15)	In2^xvi—Eu2—In2^xix	109.5
Ge1^vii—In3—Ge1^viii	111.48 (3)	In2^xvii—Eu2—In2^xix	70.5
In1^vii—In3—In1^ix	108.479 (15)	In2^xviii—Eu2—In2^xix	109.5
Ge1^v—In3—In1^ix	111.48 (3)	In2^i—Eu2—In2^xix	180.00 (2)
In1^v—In3—In1^ix	111.48 (3)	In2^xv—Eu2—Ge2^ii	109.5
Ge1^vii—In3—In1^ix	108.479 (15)	Ge2^xv—Eu2—Ge2^ii	109.5
In1^viii—In3—In1^ix	108.479 (15)	In2^xvi—Eu2—Ge2^ii	180.00 (2)
Ge1^viii—In3—In1^ix	108.479 (15)	In2^xvii—Eu2—Ge2^ii	109.5
In1^vii—In3—Ge1^ix	108.479 (15)	In2^xviii—Eu2—Ge2^ii	70.5
Ge1^v—In3—Ge1^ix	111.48 (3)	In2^i—Eu2—Ge2^ii	109.5
In1^v—In3—Ge1^ix	111.48 (3)	In2^xix—Eu2—Ge2^ii	70.5
Ge1^vii—In3—Ge1^ix	108.479 (15)	In2^xv—Eu2—Ge2^xvi	70.5
In1^viii—In3—Ge1^ix	108.479 (15)	Ge2^xv—Eu2—Ge2^xvi	70.5
Ge1^viii—In3—Ge1^ix	108.479 (15)	In2^ii—Eu2—Ge2^xvi	180.000 (12)
In1^vii—In3—Rb1^x	66.541 (9)	In2^xvii—Eu2—Ge2^xvi	70.5
Ge1^v—In3—Rb1^x	169.262 (15)	In2^xviii—Eu2—Ge2^xvi	109.5
In1^v—In3—Rb1^x	169.262 (15)	In2^i—Eu2—Ge2^xvi	70.5
Ge1^vii—In3—Rb1^x	66.541 (9)	In2^xix—Eu2—Ge2^xvi	109.5
In1^viii—In3—Rb1^x	66.541 (9)	Ge2^ii—Eu2—Ge2^xvi	180.000 (12)
Ge1^viii—In3—Rb1^x	66.541 (9)	In2^xv—Eu2—Ge2^xvii	109.5
In1^ix—In3—Rb1^x	79.262 (15)	Ge2^xv—Eu2—Ge2^xvii	109.5
Ge1^ix—In3—Rb1^x	79.262 (15)	In2^ii—Eu2—Ge2^xvii	109.5
In1^vii—In3—Rb1^xi	169.262 (15)	In2^xvi—Eu2—Ge2^xvii	70.5
Ge1^v—In3—Rb1^xi	66.541 (9)	In2^xviii—Eu2—Ge2^xvii	180.00 (4)
In1^v—In3—Rb1^xi	66.541 (9)	In2^i—Eu2—Ge2^xvii	109.5
Ge1^vii—In3—Rb1^xi	169.262 (15)	In2^xix—Eu2—Ge2^xvii	70.5
In1^viii—In3—Rb1^xi	79.262 (15)	Ge2^ii—Eu2—Ge2^xvii	109.5
Ge1^viii—In3—Rb1^xi	79.262 (15)	Ge2^xvi—Eu2—Ge2^xvii	70.5
In1^ix—In3—Rb1^xi	66.541 (9)	In2^xv—Eu2—Ge2^xviii	70.5
Ge1^ix—In3—Rb1^xi	66.541 (9)	Ge2^xv—Eu2—Ge2^xviii	70.5
Rb1^x—In3—Rb1^xi	120.0	In2^ii—Eu2—Ge2^xviii	70.5
In1^vii—In3—Rb1^v	79.262 (15)	In2^xvi—Eu2—Ge2^xviii	109.5
Ge1^v—In3—Rb1^v	66.541 (9)	In2^xvii—Eu2—Ge2^xviii	180.000 (12)
In1^v—In3—Rb1^v	66.541 (9)	In2^i—Eu2—Ge2^xviii	70.5
Ge1^vii—In3—Rb1^v	79.262 (15)	In2^xix—Eu2—Ge2^xviii	109.5
In1^viii—In3—Rb1^v	169.262 (15)	Ge2^ii—Eu2—Ge2^xviii	70.5
Ge1^viii—In3—Rb1^v	169.262 (15)	Ge2^xvi—Eu2—Ge2^xviii	109.5
In1^ix—In3—Rb1^v	66.541 (9)	Ge2^xvii—Eu2—Ge2^xviii	180.000 (12)
Ge1^ix—In3—Rb1^v	66.541 (9)

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