Ce5AuxGe4−x [x = 0 43 (2)] with the orthorhombic Sm5Ge4 structure type

inorganic papers

Acta Cryst.(2005). E61, i73–i75 doi:10.1107/S160053680501113X Bobev and Bauer _Ce

5Au0.43Ge3.57

i73

Acta Crystallographica Section E

Structure Reports Online

ISSN 1600-5368

Ce

Au

Ge

[

x

= 0.43 (2)] with the orthorhombic

Sm

Ge

structure type

Svilen Bobeva* and Eric D. Bauerb

a

Department of Chemistry and Biochemistry, 304A Drake Hall, University of Delaware, Newark, DE 19716, USA, andb_{MST-10 Mail} Stop K764, Los Alamos National Laboratory, Los Alamos, NM 87545, USA

Correspondence e-mail: sbobev@chem.udel.edu

Key indicators

Single-crystal X-ray study

T= 120 K

Mean(Ce–Ce) = 0.003 A˚ Disorder in main residue

Rfactor = 0.028

wRfactor = 0.056

Data-to-parameter ratio = 20.8

For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e.

#2005 International Union of Crystallography Printed in Great Britain – all rights reserved

Single crystals of the title compound, pentacerium gold tetragermanium, were synthesized from the corresponding elements using a eutectic Au/Ge mixture as solvent. Structure determination of a crystal from that reaction revealed the composition Ce5AuxGe4x(x= 0.43). The compound is a new

ternary derivative of the Sm5Ge4 structure type that

crystal-lizes in the space group Pnma of the orthorhombic system. There are six atoms in the asymmetric unit, one Ce in Wyckoff site 4c, two Ce in 8d, two Ge in 4cand one Ge in 8d. Two of the Ge sites are statistically occupied by Ge and Au atoms, with a lack of long-range ordering. The results are consistent with an earlier report on the structure of the fully stoichiometric analog Ce5Ge4.

Comment

Binary rare earth silicides and germanides are important materials, which have been extensively studied in the last two to three decades. Of specific interest to us was the mixed-valent Kondo material CeSi2(Kohgi et al., 1990) and its Ge

analog CeGe2. Both compounds crystallize in the

body-centered tetragonal-ThSi2structure type (Villars & Calvert,

1991). However, there are certain homogeneity regions in both systems, which present a significant challenge to

Received 24 March 2005 Accepted 11 April 2005 Online 16 April 2005

Figure 1

A view of the Ce5AuxGe4x structure projected approximately along

obtaining the phases as pure products and with defined composition. Moreover, from the crystal structure, one might expect rather anisotropic physical properties, and the avail-ability of sizeable single crystals becomes very important for precise property measurements.

To circumvent these synthetic challenges, we employed the flux-growth technique (Canfield & Fisk, 1992) to obtain high-quality single crystals from CeSi2 and CeGe2. Various

low-melting metals have been tried with differing degrees of success. In all cases, the resulting compounds were found to be solid solutions, CeMxSi2x and CeMxGe2x (M = metal

employed in the flux), or ternary Ce–M–Si and Ce–M–Ge intermetallics with different structure types. Here, we report the synthesis and structure of a new ternary Ce–Au–Ge compound. Detailed studies of the physical properties of this new material will be reported in a forthcoming publication.

The structure of Ce5AuxGe4x(x= 0.43) is a new ternary

derivative of the Sm5Ge4 structure type (Villars & Calvert,

1991). The fully stoichiometric analog Ce5Ge4 (Smith et al.,

1967) exhibits slightly different lattice parameters,a= 7.86 A˚ , b= 15.21 A˚ , andc= 8.04 A˚ , from those of the title compound. Although the cell dimensions for the latter were determined at 120 K, whereas for the unsubstituted compound the measurements were carried out at room temperature, the systematic elongation of all crystal axes of Ce5AuxGe4x(x=

0.43) is clearly seen. This is due to the nearly 18% larger atomic size of Au compared with that of Ge. Therefore, all interatomic distances are slightly longer than those in the binary phase Ce5Ge4.

Ce5AuxGe4x (x = 0.43) and its parent Ce5Ge4x

compounds can be viewed as polar intermetallics, i.e. compounds formed by electropositive and electronegative metals and semi-metals, following the Zintl concept (Zintl, 1939). There are six atoms in the asymmetric unit: Ce1 in Wyckoff site 4c, Ce2 in 8d, Ce3 in 8d, Ge1 in 4c, Ge2 in 4cand Ge3 in 8d. The structure can be considered as made up of Ge2

dumbbells and isolated Ge atoms, as shown in Fig. 1. Ge—Ge contacts with the dumbbells of 2.665 (2) A˚ compare well with Ge—Ge contacts found in other alkaline earth and rare earth germanides. The isolated Ge anions are coordinated by Ce2 cations only, and the shortest Ce—Ge contact is 2.9588 (15) A˚ , which agrees with the description above.

Experimental

All starting materials were used as received [Ce (Ames Laboratory, ingot, 99.99% metal basis), Au (Alfa, foil, 99.999%), and Ge (Alfa, pieces, 99.999%)]. A mixture of the elements in the ratio Ce:Au:Ge = 1:0.72:0.28 was loaded into an alumina crucible, which was subse-quently enclosed in an evacuated fused silica jacket by flame-sealing. The reaction was carried out at a temperature of 1373 K for 6 h, followed by slow cooling (3.5 K h1) down to 823 K. At this point, the molten flux was removed by centrifugation. The products of the reaction were small crystals with a silver metallic luster. These were later identified as Ce5AuxGe4x(x= 0.43). The crystals are stable in

air and moisture, but decompose quickly in solutions of mineral acids.

Crystal data

Ce5Au0.43Ge3.57

Mr= 1043.82

Orthorhombic,Pnma a= 7.868 (5) A˚

b= 15.258 (7) A˚

c= 8.052 (6) A˚

V= 966.6 (11) A˚3

Z= 4

Dx= 7.173 Mg m 3

MoKradiation Cell parameters from 3569

reflections

= 2.7–26.4

= 40.31 mm1

T= 120 (2) K

Irregular fragment, metallic silver 0.070.060.05 mm

Data collection

Bruker APEX SMART CCD area-detector diffractometer

!scans

Absorption correction: multi-scan (SADABS; Sheldrick, 2003)

Tmin= 0.083,Tmax= 0.139 3569 measured reflections

1021 independent reflections 953 reflections withI> 2(I)

Rint= 0.040

max= 26.4

h=9!9

k=19!0

l=10!10

Refinement

Refinement onF2

R[F2> 2(F2)] = 0.028

wR(F2_{) = 0.056}

S= 1.10 1021 reflections 49 parameters

w= 1/[2_(F

o2) + (0.0163P)2 + 12.3954P]

whereP= (Fo2+ 2Fc2)/3

(/)max< 0.001

max= 1.46 e A˚ 3

min=1.77 e A˚ 3

Extinction correction:SHELXTL

(Sheldrick, 2001)

Extinction coefficient: 0.00019 (4)

Table 1

Selected geometric parameters (A˚ ).

Ce1—Ge1/Au1i

3.064 (2) Ce1—Ge2ii

3.103 (3) Ce1—Ge3/Au3iii 3.1657 (16) Ce1—Ge3/Au3iv 3.1658 (16) Ce1—Ge2v 3.261 (2) Ce1—Ge1/Au1vi 3.299 (3) Ce1—Ce2vii 3.5409 (16) Ce1—Ce2v 3.5410 (16) Ce2—Ge3/Au3viii 2.9588 (15) Ce2—Ge3/Au3iii 2.9791 (19) Ce2—Ge3/Au3ix 3.0528 (18) Ce2—Ge1/Au1vi 3.1259 (15)

Ce2—Ge2 3.1592 (19) Ce2—Ge1/Au1i

3.2191 (15) Ce2—Ce1vi 3.5410 (16) Ce3—Ge3/Au3x 3.0884 (17) Ce3—Ge2xi 3.1738 (15) Ce3—Ge3/Au3xii 3.2898 (15) Ce3—Ge2xiii 3.3082 (17) Ce3—Ge1/Au1xiv 3.3133 (17) Ce3—Ge3/Au3xv 3.334 (2) Ce3—Ce2xvi 3.6211 (15) Ge1/Au1—Ge2v 2.665 (2)

Symmetry codes: (i) x1;y;z; (ii) x;y;z1; (iii) xþ1

2;yþ1;z 1 2; (iv)

xþ1 2;y

1 2;z

1 2; (v)xþ

1 2;y;zþ

1 2; (vi)x

1 2;y;zþ

1 2; (vii)xþ

1 2;yþ

1 2;zþ

1 2;

(viii)x;y1;z; (ix)x;yþ1;zþ1; (x)xþ3

2;yþ1;zþ 1

2; (xi)xþ1;y;z; (xii)

xþ1

2;y1;zþ 3 2; (xiii)xþ

1 2;y;zþ

3

2; (xiv)x;y;zþ1; (xv)xþ1;yþ1;zþ1;

(xvi)xþ1;y;zþ1.

The structure refinement, assuming a composition Ce5Ge4,

converged to poor residuals and two of the three crystallographically unique Ge sites (Ge1, Ge3) exhibited unusually large anisotropic displacement parameters. By freeing the site occupation factor for each individual atom, while the remaining parameters were kept fixed, it became evident that those two sites are statistically occupied by Ge and Au atoms. The third Ge site (Ge2), along with the three Ce sites, proved to be fully occupied, with corresponding deviations from full occupancy within 3. This is consistent with the slightly larger unit-cell parameters for Ce5AuxGe4x compared with those for

Ce5Ge4(Smith et al., 1967). The Ge1/Au1 site was found to be a

nearly 75:25 statistical mixture of Ce and Au, whereas the Ce3/Au3 site is close to 90:10, leading to anxvalue of 0.43 (2). The highest peak and the deepest hole in the final difference Fourier map are 0.91 and 1.40 A˚ , respectively, from the Ce1/Au1 site.

Data collection:SMART(Bruker, 2002); cell refinement:SAINT

(Bruker, 2002); data reduction:SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2001); program(s) used to refine

inorganic papers

i74

structure: SHELXTL; molecular graphics:XP inSHELXTL; soft-ware used to prepare material for publication:SHELXTL.

This work was funded in part by a University of Delaware start-up grant. Work at LANL is carried out under the auspicies of the US Department of Energy.

References

Bruker (2002).SMARTandSAINT. Bruker AXS Inc., Madison, Wisconsin, USA.

Canfield, P. C. & Fisk, Z. (1992).Philos. Mag. B,65, 1117–1123.

Kohgi, M., Ito, M., Satoh, T. Asano, H., Ishigaki, T. & Izumi, F. (1990).J. Magn. Magn. Mater.90, 433–434.

Sheldrick, G. M. (2001).SHELXTL. Bruker AXS Inc., Madison, Wisconsin, USA.

Sheldrick, G. M. (2003).SADABS. University of Go¨ttingen, Germany. Smith, G. S., Tharp, A. G. & Johnson, Q. (1967).Acta Cryst.23, 940–943. Villars, P. & Calvert, L. D. (1991).Pearson’s Handbook of Crystallographic

Data for Intermetallic Compounds, 2nd ed. Ohio: American Society for Metals.

Zintl, E. (1939).Angew. Chem.52, 1–6.

inorganic papers

Acta Cryst.(2005). E61, i73–i75 Bobev and Bauer _Ce

supporting information

sup-1

Acta Cryst. (2005). E61, i73–i75

supporting information

Acta Cryst. (2005). E61, i73–i75 [https://doi.org/10.1107/S160053680501113X]

Ce

Au

Ge

[

x

= 0.43

(2)] with the orthorhombic Sm

Ge

structure type

Svilen Bobev and Eric D. Bauer

Pentacerium gold tetragermanium

Crystal data

Ce5Au0.43Ge3.57

Mr = 1043.82 Orthorhombic, Pnma

Hall symbol: -P 2ac 2n

a = 7.868 (5) Å

b = 15.258 (7) Å

c = 8.052 (6) Å

V = 966.6 (11) Å3

Z = 4

F(000) = 1752

Dx = 7.173 Mg m−3

Mo Kα radiation, λ = 0.71073 Å Cell parameters from 3569 reflections

θ = 2.7–26.4°

µ = 40.31 mm−1

T = 120 K Irregular, grey

0.07 × 0.06 × 0.05 mm

Data collection

Bruker APEX SMART CCD area-detector diffractometer

Radiation source: fine-focus sealed tube Graphite monochromator

Detector resolution: 8.3 pixels mm-1

ω scans

Absorption correction: multi-scan (SADABS; Sheldrick, 2003)

Tmin = 0.083, Tmax = 0.139

3569 measured reflections 1021 independent reflections 953 reflections with I > 2σ(I)

Rint = 0.040

θmax = 26.4°, θmin = 2.7°

h = −9→9

k = −19→0

l = −10→10

Refinement

Refinement on F2

Least-squares matrix: full

R[F2 _{> 2σ(F}2_{)] = 0.028}

wR(F2_{) = 0.056}

S = 1.10 1021 reflections 49 parameters 0 restraints

Primary atom site location: structure-invariant direct methods

Secondary atom site location: difference Fourier map

w = 1/[σ2_(F

o2) + (0.0163P)2 + 12.3954P]

where P = (Fo2 + 2Fc2)/3

(Δ/σ)max < 0.001

Δρmax = 1.46 e Å−3

Δρmin = −1.77 e Å−3

Extinction correction: SHELXTL (Sheldrick, 2001), Fc*_{=kFc[1+0.001xFc}2_λ3_/sin(2θ)]-1/4

supporting information

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Acta Cryst. (2005). E61, i73–i75

Special details

Experimental. Crystals were selected and cut in Exxon Paratone N oil bath to the desired dimensions. A suitable one was chosen and it was mounted on the top of glass fiber and quickly placed under the cold nitrogen stream (ca 120 K) in a Bruker SMART CCD-based diffractometer. The crystal, despite the small size, diffracted strongly and an exposure time of 5 second per frame was found sufficient. The structure was solved readily using direct methods and refined on F2 _using

the SHELXL package (Sheldrick, 2001). Data collection was 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 were 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 F}2_,

conventional R-factors R are based on F, with F set to zero for negative F2_{. The threshold expression of F}2 _{> σ(F}2_{) is used}

only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2

are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2₎

x y z Uiso*/Ueq Occ. (<1)

Ce1 0.29830 (10) 0.2500 0.00310 (9) 0.0104 (2) Ce2 0.12843 (7) 0.11570 (4) 0.34014 (6) 0.00863 (16) Ce3 0.98567 (6) 0.09877 (4) 0.81688 (6) 0.00863 (16)

Ge1 0.92333 (12) 0.2500 0.10583 (12) 0.0077 (4) 0.751 (4) Au1 0.92333 (12) 0.2500 0.10583 (12) 0.0077 (4) 0.249 (4) Ge2 0.18878 (17) 0.2500 0.63289 (17) 0.0071 (3)

Ge3 0.20994 (11) 0.95676 (6) 0.53502 (11) 0.0103 (3) 0.910 (3) Au3 0.20994 (11) 0.95676 (6) 0.53502 (11) 0.0103 (3) 0.090 (3)

Atomic displacement parameters (Å2₎

U11 _U22 _U33 _U12 _U13 _U23

Ce1 0.0144 (4) 0.0078 (4) 0.0091 (4) 0.000 −0.0003 (3) 0.000 Ce2 0.0104 (3) 0.0071 (3) 0.0084 (3) 0.0002 (2) 0.0006 (2) −0.0013 (2) Ce3 0.0089 (3) 0.0084 (3) 0.0085 (3) −0.0001 (2) −0.0005 (2) 0.0013 (2) Ge1 0.0093 (5) 0.0067 (6) 0.0070 (6) 0.000 −0.0005 (4) 0.000 Au1 0.0093 (5) 0.0067 (6) 0.0070 (6) 0.000 −0.0005 (4) 0.000 Ge2 0.0090 (7) 0.0053 (7) 0.0072 (7) 0.000 −0.0004 (5) 0.000 Ge3 0.0157 (5) 0.0081 (5) 0.0072 (5) −0.0026 (3) 0.0008 (4) 0.0005 (3) Au3 0.0157 (5) 0.0081 (5) 0.0072 (5) −0.0026 (3) 0.0008 (4) 0.0005 (3)

Geometric parameters (Å, º)

Ce1—Au1i _{3.064 (2) Ce3—Ge1}xiv _{3.3133 (17)}

Ce1—Ge1i _{3.064 (2) Ce3—Au3}xv _{3.334 (2)}

Ce1—Ge2ii _{3.103 (3) Ce3—Ge3}xv _{3.334 (2)}

Ce1—Au3iii _{3.1657 (16) Ce3—Au3}xvi _{3.5999 (17)}

Ce1—Ge3iii _{3.1657 (16) Ce3—Ce2}xvii _{3.6211 (15)}

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Acta Cryst. (2005). E61, i73–i75

Ce1—Ge3iv _{3.1658 (16) Ge1—Ce1}xi _{3.064 (2)}

Ce1—Ge2v _{3.261 (2) Ge1—Ce2}vii _{3.1259 (15)}

Ce1—Au1vi _{3.299 (3) Ge1—Ce2}v _{3.1259 (15)}

Ce1—Ge1vi _{3.299 (3) Ge1—Ce2}xviii _{3.2191 (15)}

Ce1—Ce2vii _{3.5409 (16) Ge1—Ce2}xi _{3.2191 (15)}

Ce1—Ce2v _{3.5410 (16) Ge1—Ce1}v _{3.299 (3)}

Ce2—Au3viii _{2.9588 (15) Ge1—Ce3}xix _{3.3132 (17)}

Ce2—Ge3viii _{2.9588 (15) Ge1—Ce3}ii _{3.3132 (17)}

Ce2—Au3iii _{2.9791 (19) Ge2—Au1}vi _{2.665 (2)}

Ce2—Ge3iii _{2.9791 (19) Ge2—Ge1}vi _{2.665 (2)}

Ce2—Au3ix _{3.0528 (18) Ge2—Ce1}xiv _{3.103 (3)}

Ce2—Ge3ix _{3.0528 (18) Ge2—Ce2}xx _{3.1592 (19)}

Ce2—Au1vi _{3.1259 (15) Ge2—Ce3}xxi _{3.1737 (15)}

Ce2—Ge1vi _{3.1259 (15) Ge2—Ce3}i _{3.1738 (15)}

Ce2—Ge2 3.1592 (19) Ge2—Ce1vi _{3.261 (2)}

Ce2—Ge1i _{3.2191 (15) Ge2—Ce3}xxii _{3.3081 (17)}

Ce2—Au1i _{3.2191 (15) Ge2—Ce3}xxiii _{3.3081 (17)}

Ce2—Ce1vi _{3.5410 (16) Ge3—Ce2}xxiv _{2.9588 (15)}

Ce3—Au3x _{3.0884 (17) Ge3—Ce2}xxv _{2.9791 (19)}

Ce3—Ge3x _{3.0884 (17) Ge3—Ce2}ix _{3.0528 (18)}

Ce3—Ge2xi _{3.1738 (15) Ge3—Ce3}xxvi _{3.0884 (17)}

Ce3—Au3xii _{3.2898 (15) Ge3—Ce1}xxv _{3.1657 (16)}

Ce3—Ge3xii _{3.2898 (15) Ge3—Ce3}xxvii _{3.2898 (15)}

Ce3—Ge2xiii _{3.3082 (17) Ge3—Ce3}xv _{3.334 (2)}

Ce3—Au1xiv _{3.3133 (17)}

Au1i_—Ce1—Ge1i _{0.00 (4) Au3}xii_—Ce3—Au1xiv _{96.12 (4)}

Au1i_—Ce1—Ge2ii _{89.54 (5) Ge3}xii_—Ce3—Au1xiv _{96.12 (4)}

Ge1i_—Ce1—Ge2ii _{89.54 (5) Ge2}xiii_—Ce3—Au1xiv _{47.46 (3)}

Au1i_—Ce1—Au3iii _{87.61 (2) Au3}x_—Ce3—Ge1xiv _{84.63 (4)}

Ge1i_—Ce1—Au3iii _{87.61 (2) Ge3}x_—Ce3—Ge1xiv _{84.63 (4)}

Ge2ii_—Ce1—Au3iii _{94.15 (2) Ge2}xi_—Ce3—Ge1xiv _{84.03 (5)}

Au1i_—Ce1—Ge3iii _{87.61 (2) Au3}xii_—Ce3—Ge1xiv _{96.12 (4)}

Ge1i_—Ce1—Ge3iii _{87.61 (2) Ge3}xii_—Ce3—Ge1xiv _{96.12 (4)}

Ge2ii_—Ce1—Ge3iii _{94.15 (2) Ge2}xiii_—Ce3—Ge1xiv _{47.46 (3)}

Au3iii_—Ce1—Ge3iii _{0.00 (4) Au1}xiv_—Ce3—Ge1xiv _{0.00 (4)}

Au1i_—Ce1—Au3iv _{87.61 (2) Au3}x_—Ce3—Au3xv _{140.50 (4)}

Ge1i_—Ce1—Au3iv _{87.61 (2) Ge3}x_—Ce3—Au3xv _{140.50 (4)}

Ge2ii_—Ce1—Au3iv _{94.15 (2) Ge2}xi_—Ce3—Au3xv _{91.17 (5)}

Au3iii_—Ce1—Au3iv _{170.40 (4) Au3}xii_—Ce3—Au3xv _{80.58 (4)}

Ge3iii_—Ce1—Au3iv _{170.40 (4) Ge3}xii_—Ce3—Au3xv _{80.58 (4)}

Au1i_—Ce1—Ge3iv _{87.61 (2) Ge2}xiii_—Ce3—Au3xv _{87.43 (4)}

Ge1i_—Ce1—Ge3iv _{87.61 (2) Au1}xiv_—Ce3—Au3xv _{134.87 (4)}

Ge2ii_—Ce1—Ge3iv _{94.15 (2) Ge1}xiv_—Ce3—Au3xv _{134.87 (4)}

Au3iii_—Ce1—Ge3iv _{170.40 (4) Au3}x_—Ce3—Ge3xv _{140.50 (4)}

Ge3iii_—Ce1—Ge3iv _{170.40 (4) Ge3}x_—Ce3—Ge3xv _{140.50 (4)}

Au3iv_—Ce1—Ge3iv _{0.00 (4) Ge2}xi_—Ce3—Ge3xv _{91.17 (5)}

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Acta Cryst. (2005). E61, i73–i75

Ge1i_—Ce1—Ge2v _{176.05 (4) Ge3}xii_—Ce3—Ge3xv _{80.58 (4)}

Ge2ii_—Ce1—Ge2v _{86.51 (4) Ge2}xiii_—Ce3—Ge3xv _{87.43 (4)}

Au3iii_—Ce1—Ge2v _{92.67 (2) Au1}xiv_—Ce3—Ge3xv _{134.87 (4)}

Ge3iii_—Ce1—Ge2v _{92.67 (2) Ge1}xiv_—Ce3—Ge3xv _{134.87 (4)}

Au3iv_—Ce1—Ge2v _{92.67 (2) Au3}xv_—Ce3—Ge3xv _{0.00 (4)}

Ge3iv_—Ce1—Ge2v _{92.67 (2) Au3}x_—Ce3—Au3xvi _{79.24 (5)}

Au1i_—Ce1—Au1vi _{91.69 (4) Ge3}x_—Ce3—Au3xvi _{79.24 (5)}

Ge1i_—Ce1—Au1vi _{91.69 (4) Ge2}xi_—Ce3—Au3xvi _{84.06 (5)}

Ge2ii_—Ce1—Au1vi _{178.77 (4) Au3}xii_—Ce3—Au3xvi _{98.93 (4)}

Au3iii_—Ce1—Au1vi _{85.91 (2) Ge3}xii_—Ce3—Au3xvi _{98.93 (4)}

Ge3iii_—Ce1—Au1vi _{85.91 (2) Ge2}xiii_—Ce3—Au3xvi _{147.46 (4)}

Au3iv_—Ce1—Au1vi _{85.91 (2) Au1}xiv_—Ce3—Au3xvi _{159.14 (3)}

Ge3iv_—Ce1—Au1vi _{85.91 (2) Ge1}xiv_—Ce3—Au3xvi _{159.14 (3)}

Ge2v_—Ce1—Au1vi _{92.27 (5) Au3}xv_—Ce3—Au3xvi _{62.45 (5)}

Au1i_—Ce1—Ge1vi _{91.69 (4) Ge3}xv_—Ce3—Au3xvi _{62.45 (5)}

Ge1i_—Ce1—Ge1vi _{91.69 (4) Au3}x_—Ce3—Ce2xvii _{98.22 (3)}

Ge2ii_—Ce1—Ge1vi _{178.77 (4) Ge3}x_—Ce3—Ce2xvii _{98.22 (3)}

Au3iii_—Ce1—Ge1vi _{85.91 (2) Ge2}xi_—Ce3—Ce2xvii _{128.23 (4)}

Ge3iii_—Ce1—Ge1vi _{85.91 (2) Au3}xii_—Ce3—Ce2xvii _{50.79 (3)}

Au3iv_—Ce1—Ge1vi _{85.91 (2) Ge3}xii_—Ce3—Ce2xvii _{50.79 (3)}

Ge3iv_—Ce1—Ge1vi _{85.91 (2) Ge2}xiii_—Ce3—Ce2xvii _{119.87 (4)}

Ge2v_—Ce1—Ge1vi _{92.27 (5) Au1}xiv_—Ce3—Ce2xvii _{146.91 (3)}

Au1vi_—Ce1—Ge1vi _{0.00 (3) Ge1}xiv_—Ce3—Ce2xvii _{146.91 (3)}

Au1i_—Ce1—Ce2vii _{127.59 (4) Au3}xv_—Ce3—Ce2xvii _{50.147 (19)}

Ge1i_—Ce1—Ce2vii _{127.59 (4) Ge3}xv_—Ce3—Ce2xvii _{50.147 (19)}

Ge2ii_—Ce1—Ce2vii _{123.10 (3) Au3}xvi_—Ce3—Ce2xvii _{50.02 (3)}

Au3iii_—Ce1—Ce2vii _{124.25 (3) Ge2}v_—Ge1—Ce1xi _{118.17 (6)}

Ge3iii_—Ce1—Ce2vii _{124.25 (3) Ge2}v_—Ge1—Ce2vii _{65.57 (4)}

Au3iv_—Ce1—Ce2vii _{53.80 (3) Ce1}xi_—Ge1—Ce2vii _{138.78 (3)}

Ge3iv_—Ce1—Ce2vii _{53.80 (3) Ge2}v_—Ge1—Ce2v _{65.57 (4)}

Ge2v_—Ce1—Ce2vii _{55.16 (4) Ce1}xi_—Ge1—Ce2v _{138.78 (3)}

Au1vi_—Ce1—Ce2vii _{56.02 (2) Ce2}vii_—Ge1—Ce2v _{81.92 (5)}

Ge1vi_—Ce1—Ce2vii _{56.02 (2) Ge2}v_—Ge1—Ce2xviii _{140.35 (2)}

Au1i_—Ce1—Ce2v _{127.59 (4) Ce1}xi_—Ge1—Ce2xviii _{71.07 (4)}

Ge1i_—Ce1—Ce2v _{127.59 (4) Ce2}vii_—Ge1—Ce2xviii _{82.72 (4)}

Ge2ii_—Ce1—Ce2v _{123.10 (3) Ce2}v_—Ge1—Ce2xviii _{135.06 (4)}

Au3iii_—Ce1—Ce2v _{53.80 (3) Ge2}v_—Ge1—Ce2xi _{140.35 (2)}

Ge3iii_—Ce1—Ce2v _{53.80 (3) Ce1}xi_—Ge1—Ce2xi _{71.07 (4)}

Au3iv_—Ce1—Ce2v _{124.25 (3) Ce2}vii_—Ge1—Ce2xi _{135.06 (4)}

Ge3iv_—Ce1—Ce2v _{124.25 (3) Ce2}v_—Ge1—Ce2xi _{82.72 (4)}

Ge2v_—Ce1—Ce2v _{55.16 (4) Ce2}xviii_—Ge1—Ce2xi _{79.07 (5)}

Au1vi_—Ce1—Ce2v _{56.02 (2) Ge2}v_—Ge1—Ce1v _{118.82 (6)}

Ge1vi_—Ce1—Ce2v _{56.02 (2) Ce1}xi_—Ge1—Ce1v _{123.01 (4)}

Ce2vii_—Ce1—Ce2v _{70.72 (4) Ce2}vii_—Ge1—Ce1v _{69.26 (2)}

Au3viii_—Ce2—Ge3viii _{0.00 (5) Ce2}v_—Ge1—Ce1v _{69.26 (2)}

Au3viii_—Ce2—Au3iii _{92.33 (4) Ce2}xviii_—Ge1—Ce1v _{65.80 (4)}

Ge3viii_—Ce2—Au3iii _{92.33 (4) Ce2}xi_—Ge1—Ce1v _{65.80 (4)}

supporting information

sup-5

Acta Cryst. (2005). E61, i73–i75

Ge3viii_—Ce2—Ge3iii _{92.33 (4) Ce1}xi_—Ge1—Ce3xix _{70.60 (2)}

Au3iii_—Ce2—Ge3iii _{0.00 (5) Ce2}vii_—Ge1—Ce3xix _{75.59 (3)}

Au3viii_—Ce2—Au3ix _{73.60 (4) Ce2}v_—Ge1—Ce3xix _{131.62 (4)}

Ge3viii_—Ce2—Au3ix _{73.60 (4) Ce2}xviii_—Ge1—Ce3xix _{83.92 (5)}

Au3iii_—Ce2—Au3ix _{120.62 (4) Ce2}xi_—Ge1—Ce3xix _{141.32 (4)}

Ge3iii_—Ce2—Au3ix _{120.62 (4) Ce1}v_—Ge1—Ce3xix _{135.59 (3)}

Au3viii_—Ce2—Ge3ix _{73.60 (4) Ge2}v_—Ge1—Ce3ii _{66.17 (4)}

Ge3viii_—Ce2—Ge3ix _{73.60 (4) Ce1}xi_—Ge1—Ce3ii _{70.60 (2)}

Au3iii_—Ce2—Ge3ix _{120.62 (4) Ce2}vii_—Ge1—Ce3ii _{131.62 (4)}

Ge3iii_—Ce2—Ge3ix _{120.62 (4) Ce2}v_—Ge1—Ce3ii _{75.59 (3)}

Au3ix_—Ce2—Ge3ix _{0.00 (5) Ce2}xviii_—Ge1—Ce3ii _{141.32 (4)}

Au3viii_—Ce2—Au1vi _{107.62 (4) Ce2}xi_—Ge1—Ce3ii _{83.92 (5)}

Ge3viii_—Ce2—Au1vi _{107.62 (4) Ce1}v_—Ge1—Ce3ii _{135.59 (3)}

Au3iii_—Ce2—Au1vi _{92.36 (4) Ce3}xix_—Ge1—Ce3ii _{88.28 (6)}

Ge3iii_—Ce2—Au1vi _{92.36 (4) Au1}vi_—Ge2—Ge1vi _{0.00 (4)}

Au3ix_—Ce2—Au1vi _{147.01 (4) Au1}vi_—Ge2—Ce1xiv _{120.05 (7)}

Ge3ix_—Ce2—Au1vi _{147.01 (4) Ge1}vi_—Ge2—Ce1xiv _{120.05 (7)}

Au3viii_—Ce2—Ge1vi _{107.62 (4) Au1}vi_—Ge2—Ce2xx _{64.27 (5)}

Ge3viii_—Ce2—Ge1vi _{107.62 (4) Ge1}vi_—Ge2—Ce2xx _{64.27 (5)}

Au3iii_—Ce2—Ge1vi _{92.36 (4) Ce1}xiv_—Ge2—Ce2xx _{139.33 (3)}

Ge3iii_—Ce2—Ge1vi _{92.36 (4) Au1}vi_{—Ge2—Ce2 64.27 (5)}

Au3ix_—Ce2—Ge1vi _{147.01 (4) Ge1}vi_{—Ge2—Ce2 64.27 (5)}

Ge3ix_—Ce2—Ge1vi _{147.01 (4) Ce1}xiv_{—Ge2—Ce2 139.33 (3)}

Au1vi_—Ce2—Ge1vi _{0.0 Ce2}xx_{—Ge2—Ce2 80.88 (6)}

Au3viii_{—Ce2—Ge2 95.93 (5) Au1}vi_—Ge2—Ce3xxi _{133.27 (3)}

Ge3viii_{—Ce2—Ge2 95.93 (5) Ge1}vi_—Ge2—Ce3xxi _{133.27 (3)}

Au3iii_{—Ce2—Ge2 142.36 (4) Ce1}xiv_—Ge2—Ce3xxi _{72.02 (4)}

Ge3iii_{—Ce2—Ge2 142.36 (4) Ce2}xx_—Ge2—Ce3xxi _{78.53 (5)}

Au3ix_{—Ce2—Ge2 96.91 (4) Ce2—Ge2—Ce3}xxi _{138.09 (5)}

Ge3ix_{—Ce2—Ge2 96.91 (4) Au1}vi_—Ge2—Ce3i _{133.27 (3)}

Au1vi_{—Ce2—Ge2 50.16 (3) Ge1}vi_—Ge2—Ce3i _{133.27 (3)}

Ge1vi_{—Ce2—Ge2 50.16 (3) Ce1}xiv_—Ge2—Ce3i _{72.02 (4)}

Au3viii_—Ce2—Ge1i _{160.26 (3) Ce2}xx_—Ge2—Ce3i _{138.09 (5)}

Ge3viii_—Ce2—Ge1i _{160.26 (3) Ce2—Ge2—Ce3}i _{78.52 (5)}

Au3iii_—Ce2—Ge1i _{88.10 (5) Ce3}xxi_—Ge2—Ce3i _{93.28 (6)}

Ge3iii_—Ce2—Ge1i _{88.10 (5) Au1}vi_—Ge2—Ce1vi _{114.22 (7)}

Au3ix_—Ce2—Ge1i _{89.22 (5) Ge1}vi_—Ge2—Ce1vi _{114.22 (7)}

Ge3ix_—Ce2—Ge1i _{89.22 (5) Ce1}xiv_—Ge2—Ce1vi _{125.74 (5)}

Au1vi_—Ce2—Ge1i _{92.08 (4) Ce2}xx_—Ge2—Ce1vi _{66.92 (3)}

Ge1vi_—Ce2—Ge1i _{92.08 (4) Ce2—Ge2—Ce1}vi _{66.92 (3)}

Ge2—Ce2—Ge1i _{95.72 (5) Ce3}xxi_—Ge2—Ce1vi _{71.48 (4)}

Au3viii_—Ce2—Au1i _{160.26 (3) Ce3}i_—Ge2—Ce1vi _{71.49 (4)}

Ge3viii_—Ce2—Au1i _{160.26 (3) Au1}vi_—Ge2—Ce3xxii _{66.37 (4)}

Au3iii_—Ce2—Au1i _{88.10 (5) Ge1}vi_—Ge2—Ce3xxii _{66.37 (4)}

Ge3iii_—Ce2—Au1i _{88.10 (5) Ce1}xiv_—Ge2—Ce3xxii _{71.73 (3)}

Au3ix_—Ce2—Au1i _{89.22 (5) Ce2}xx_—Ge2—Ce3xxii _{75.22 (3)}

Ge3ix_—Ce2—Au1i _{89.22 (5) Ce2—Ge2—Ce3}xxii _{130.52 (5)}

supporting information

sup-6

Acta Cryst. (2005). E61, i73–i75

Ge1vi_—Ce2—Au1i _{92.08 (4) Ce3}i_—Ge2—Ce3xxii _{143.66 (5)}

Ge2—Ce2—Au1i _{95.72 (5) Ce1}vi_—Ge2—Ce3xxii _{134.92 (3)}

Ge1i_—Ce2—Au1i _{0.00 (3) Au1}vi_—Ge2—Ce3xxiii _{66.37 (4)}

Au3viii_—Ce2—Ce1vi _{116.38 (4) Ge1}vi_—Ge2—Ce3xxiii _{66.37 (4)}

Ge3viii_—Ce2—Ce1vi _{116.38 (4) Ce1}xiv_—Ge2—Ce3xxiii _{71.73 (3)}

Au3iii_—Ce2—Ce1vi _{145.26 (3) Ce2}xx_—Ge2—Ce3xxiii _{130.52 (5)}

Ge3iii_—Ce2—Ce1vi _{145.26 (3) Ce2—Ge2—Ce3}xxiii _{75.22 (3)}

Au3ix_—Ce2—Ce1vi _{56.81 (4) Ce3}xxi_—Ge2—Ce3xxiii _{143.66 (5)}

Ge3ix_—Ce2—Ce1vi _{56.81 (4) Ce3}i_—Ge2—Ce3xxiii _{77.96 (4)}

Au1vi_—Ce2—Ce1vi _{96.63 (5) Ce1}vi_—Ge2—Ce3xxiii _{134.92 (3)}

Ge1vi_—Ce2—Ce1vi _{96.63 (5) Ce3}xxii_—Ge2—Ce3xxiii _{88.45 (6)}

Ge2—Ce2—Ce1vi _{57.92 (4) Ce2}xxiv_—Ge3—Ce2xxv _{146.51 (3)}

Ge1i_—Ce2—Ce1vi _{58.18 (4) Ce2}xxiv_—Ge3—Ce2ix _{106.40 (4)}

Au1i_—Ce2—Ce1vi _{58.18 (4) Ce2}xxv_—Ge3—Ce2ix _{88.07 (4)}

Au3x_—Ce3—Ge3x _{0.00 (4) Ce2}xxiv_—Ge3—Ce3xxvi _{95.24 (4)}

Au3x_—Ce3—Ge2xi _{94.27 (5) Ce2}xxv_—Ge3—Ce3xxvi _{92.08 (6)}

Ge3x_—Ce3—Ge2xi _{94.27 (5) Ce2}ix_—Ge3—Ce3xxvi _{139.83 (4)}

Au3x_—Ce3—Au3xii _{97.15 (5) Ce2}xxiv_—Ge3—Ce1xxv _{140.29 (4)}

Ge3x_—Ce3—Au3xii _{97.15 (5) Ce2}xxv_—Ge3—Ce1xxv _{72.90 (3)}

Ge2xi_—Ce3—Au3xii _{168.54 (3) Ce2}ix_—Ge3—Ce1xxv _{69.39 (3)}

Au3x_—Ce3—Ge3xii _{97.15 (5) Ce3}xxvi_—Ge3—Ce1xxv _{72.32 (3)}

Ge3x_—Ce3—Ge3xii _{97.15 (5) Ce2}xxiv_—Ge3—Ce3xxvii _{78.19 (4)}

Ge2xi_—Ce3—Ge3xii _{168.54 (3) Ce2}xxv_—Ge3—Ce3xxvii _{70.37 (4)}

Au3xii_—Ce3—Ge3xii _{0.00 (4) Ce2}ix_—Ge3—Ce3xxvii _{133.96 (4)}

Au3x_—Ce3—Ge2xiii _{132.02 (4) Ce3}xxvi_—Ge3—Ce3xxvii _{82.85 (5)}

Ge3x_—Ce3—Ge2xiii _{132.02 (4) Ce1}xxv_—Ge3—Ce3xxvii _{134.37 (4)}

Ge2xi_—Ce3—Ge2xiii _{84.58 (4) Ce2}xxiv_—Ge3—Ce3xv _{69.97 (4)}

Au3xii_—Ce3—Ge2xiii _{87.11 (5) Ce2}xxv_—Ge3—Ce3xv _{143.48 (4)}

Ge3xii_—Ce3—Ge2xiii _{87.11 (5) Ce2}ix_—Ge3—Ce3xv _{77.60 (5)}

Au3x_—Ce3—Au1xiv _{84.63 (4) Ce3}xxvi_—Ge3—Ce3xv _{78.75 (5)}

Ge3x_—Ce3—Au1xiv _{84.63 (4) Ce1}xxv_—Ge3—Ce3xv _{70.63 (3)}

Ge2xi_—Ce3—Au1xiv _{84.03 (5) Ce3}xxvii_—Ge3—Ce3xv _{141.24 (3)}