Incommensurately modulated lanthanide coinage-metal diarsenides. II. GdCuAs2, GdAu1−δAs2 and TbAu1−δAs2 – new distortion variants of the HfCuSi2 type with irregularly stacked zigzag chains of arsenic atoms

Rutzinger, D.; Bartsch, C.; Doert, T.; Ruck, M.

doi:10.1107/S0108768109029565

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Incommensurately modulated lanthanide coinage-metal diarsenides. II. GdCuAs₂, GdAu_1−δAs₂ and TbAu_1−δAs₂ – new distortion variants of the HfCuSi₂ type with irregularly stacked zigzag chains of arsenic atoms

D. Rutzinger, C. Bartsch, T. Doert and M. Ruck

GdCuAs₂, GdAu_1−δAs₂ and TbAu_1−δAs₂ crystallize as incommensurately modulated variants of the HfCuSi₂ type. Structure models have been developed in the monoclinic superspace group P12₁/m1(α0γ)00 (No. 11.1). The components of the modulation wavevectors q = αa* + 0b* + γc* are α = 0.04 (1) and γ = 0.48 (1) for GdCuAs₂, α = 0.03 (1) and γ = 0.48 (1) for GdAu_1−δAs₂ and α = 0.02 (1) and γ = 0.46 (1) for TbAu_1−δAs₂. The predominant effect of the positional modulation is the distortion of a square net of arsenic atoms, which results in planar zigzag chains. Rod groups and layer groups of the respective structure motifs are identified and discussed.

Keywords: incommensurately modulated structures; distortion; layered-type structures.

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Supporting information

	Crystallographic Information File (CIF) https://doi.org/10.1107/S0108768109029565/ck5036sup1.cif Contains datablocks global, I, II, III
	Structure factor file (CIF format) https://doi.org/10.1107/S0108768109029565/ck5036Isup2.hkl Contains datablock I

Computing details top

For all compounds, data collection: X-AREA, STOE, 2006; cell refinement: X-AREA, STOE, 2006; data reduction: X-AREA, STOE, 2002; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: Jana2000 (Petricek, Dusek & Palatinus, 2000); molecular graphics: DIAMOND-Visuelles Informationssystem für Kristallstrukturen

(G. Bergerhoff, Bonn, 1999); software used to prepare material for publication: Jana2000 (Petricek, Dusek & Palatinus, 2000).

Figures top

(I) top

Crystal data top

As₂CuGd	F(000) = 318
M_r = 370.6	D_x = 8.153 Mg m⁻³
Monoclinic, P21/m(α0γ)00†	Mo Kα radiation, λ = 0.71073 Å
q = 0.03570a* + 0.47900c*	Cell parameters from 10083 reflections
a = 3.9041 (8) Å	θ = 3.0–33.5°
b = 3.9015 (8) Å	µ = 50.25 mm⁻¹
c = 9.908 (2) Å	T = 293 K
β = 90.05 (3)°	Platelet, black
V = 150.92 (5) Å³	0.26 × 0.06 × 0.02 mm
Z = 2

† Symmetry operations: (1) x₁, x₂, x₃, x₄; (2) −x₁, 1/2+x₂, −x₃, −x₄; (3) −x₁, −x₂, −x₃, −x₄; (4) x₁, 1/2−x₂, x₃, x₄.

Data collection top

STOE IPDS 2 diffractometer	2043 independent reflections
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus	751 reflections with I > 3σ(I)
Plane graphite monochromator	R_int = 0.094
Detector resolution: 6.67 pixels mm^-1	θ_max = 34.2°, θ_min = 3.1°
ω scans	h = −6→6
Absorption correction: numerical (Jana2000; Petricek, Dusek & Palatinus, 2000)	k = −5→6
T_min = 0.128, T_max = 0.460	l = −16→16
10072 measured reflections

Refinement top

Refinement on F	Weighting scheme based on measured s.u.'s w = 1/(σ²(F) + 0.0001F²)
R[F² > 2σ(F²)] = 0.039	(Δ/σ)_max = 0.022
wR(F²) = 0.039	Δρ_max = 1.64 e Å⁻³
S = 1.24	Δρ_min = −1.97 e Å⁻³
2043 reflections	Extinction correction: B-C type 1 Gaussian isotropic (Becker & Coppens, 1974)
77 parameters	Extinction coefficient: 0.14 (1)

Crystal data top

As₂CuGd	β = 90.05 (3)°
M_r = 370.6	V = 150.92 (5) Å³
Monoclinic, P21/m(α0γ)00†	Z = 2
q = 0.03570a* + 0.47900c*	Mo Kα radiation
a = 3.9041 (8) Å	µ = 50.25 mm⁻¹
b = 3.9015 (8) Å	T = 293 K
c = 9.908 (2) Å	0.26 × 0.06 × 0.02 mm

† Symmetry operations: (1) x₁, x₂, x₃, x₄; (2) −x₁, 1/2+x₂, −x₃, −x₄; (3) −x₁, −x₂, −x₃, −x₄; (4) x₁, 1/2−x₂, x₃, x₄.

Data collection top

STOE IPDS 2 diffractometer	2043 independent reflections
Absorption correction: numerical (Jana2000; Petricek, Dusek & Palatinus, 2000)	751 reflections with I > 3σ(I)
T_min = 0.128, T_max = 0.460	R_int = 0.094
10072 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.039	77 parameters
wR(F²) = 0.039	Δρ_max = 1.64 e Å⁻³
S = 1.24	Δρ_min = −1.97 e Å⁻³
2043 reflections

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

	x	y	z	U_iso*/U_eq
Gd	0.2476 (3)	0.25	0.76146 (4)	0.01281 (10)
Cu	0.7439 (13)	0.25	0.49985 (18)	0.0166 (3)
As1	0.2543 (7)	0.25	0.34179 (8)	0.0134 (2)
As2	0.7398 (11)	0.25	0.99949 (15)	0.0173 (3)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Gd	0.00981 (17)	0.01209 (18)	0.01652 (16)	0	0.0015 (9)	0
Cu	0.0137 (7)	0.0150 (5)	0.0210 (6)	0	−0.005 (2)	0
As1	0.0095 (3)	0.0115 (3)	0.0192 (4)	0	−0.0026 (15)	0
As2	0.0154 (6)	0.0192 (5)	0.0173 (4)	0	−0.0014 (14)	0

Bond lengths (Å) top

	Average	Minimum	Maximum
Gd—Cuⁱ	3.253 (6)	3.239 (6)	3.268 (6)
Gd—Cu	3.236 (6)	3.213 (6)	3.260 (6)
Gd—Cuⁱⁱ	3.242 (5)	3.228 (5)	3.255 (5)
Gd—Cuⁱⁱⁱ	3.242 (5)	3.228 (5)	3.255 (5)
Gd—As1^iv	2.948 (3)	2.945 (3)	2.951 (3)
Gd—As1^v	2.948 (3)	2.945 (3)	2.951 (3)
Gd—As1ⁱⁱ	2.938 (3)	2.934 (3)	2.943 (3)
Gd—As1ⁱⁱⁱ	2.938 (3)	2.934 (3)	2.943 (3)
Gd—As2ⁱ	3.082 (5)	3.017 (5)	3.145 (5)
Gd—As2	3.042 (5)	3.026 (5)	3.059 (5)
Gd—As2^vi	3.070 (4)	3.037 (4)	3.107 (4)
Gd—As2^vii	3.070 (4)	3.037 (4)	3.107 (4)
Cu—Cuⁱⁱ	2.726 (5)	2.724 (5)	2.728 (5)
Cu—Cuⁱⁱⁱ	2.726 (5)	2.724 (5)	2.728 (5)
Cu—Cu^viii	2.794 (5)	2.787 (5)	2.801 (5)
Cu—Cu^ix	2.794 (5)	2.787 (5)	2.801 (5)
Cu—As1	2.471 (7)	2.464 (7)	2.478 (7)
Cu—As1^x	2.535 (7)	2.521 (7)	2.548 (7)
Cu—As1ⁱⁱ	2.503 (5)	2.492 (5)	2.515 (5)
Cu—As1ⁱⁱⁱ	2.503 (5)	2.492 (5)	2.515 (5)
As2—As2^vi	2.705 (5)	2.568 (4)	2.850 (5)
As2—As2^vii	2.705 (5)	2.568 (4)	2.850 (5)
As2—As2^xi	2.820 (5)	2.675 (5)	2.967 (5)
As2—As2^xii	2.820 (5)	2.675 (5)	2.967 (5)

Symmetry codes: (i) x₁−1, x₂, x₃, x₄; (ii) −x₁+1, −x₂, −x₃+1, −x₄; (iii) −x₁+1, −x₂+1, −x₃+1, −x₄; (iv) −x₁, −x₂, −x₃+1, −x₄; (v) −x₁, −x₂+1, −x₃+1, −x₄; (vi) −x₁+1, −x₂, −x₃+2, −x₄; (vii) −x₁+1, −x₂+1, −x₃+2, −x₄; (viii) −x₁+2, −x₂, −x₃+1, −x₄; (ix) −x₁+2, −x₂+1, −x₃+1, −x₄; (x) x₁+1, x₂, x₃, x₄; (xi) −x₁+2, −x₂, −x₃+2, −x₄; (xii) −x₁+2, −x₂+1, −x₃+2, −x₄.

(II) top

Crystal data top

As₂Au_0.973Gd	F(000) = 414
M_r = 498.7	D_x = 10.174 Mg m⁻³
Monoclinic, P21/m(α0γ)00†	Mo Kα radiation, λ = 0.71073 Å
q = 0.03000a* + 0.48000c*	Cell parameters from 6594 reflections
a = 3.9570 (8) Å	θ = 3.0–33.5°
b = 4.060 (2) Å	µ = 83.84 mm⁻¹
c = 10.135 (2) Å	T = 293 K
β = 90.01 (3)°	Platelet, black
V = 162.82 (9) Å³	0.31 × 0.06 × 0.0025 mm
Z = 2

† Symmetry operations: (1) x₁, x₂, x₃, x₄; (2) −x₁, 1/2+x₂, −x₃, −x₄; (3) −x₁, −x₂, −x₃, −x₄; (4) x₁, 1/2−x₂, x₃, x₄.

Data collection top

STOE IPDS 2 diffractometer	2428 independent reflections
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus	1634 reflections with I > 3σ(I)
Plane graphite monochromator	R_int = 0.077
Detector resolution: 6.67 pixels mm^-1	θ_max = 33.8°, θ_min = 3.0°
ω scans	h = −6→5
Absorption correction: numerical (Jana2000; Petricek, Dusek & Palatinus, 2000)	k = −6→6
T_min = 0.064, T_max = 0.807	l = −16→13
9508 measured reflections

Refinement top

Refinement on F	Weighting scheme based on measured s.u.'s w = 1/(σ²(F) + 0.0001F²)
R[F² > 2σ(F²)] = 0.046	(Δ/σ)_max = 0.042
wR(F²) = 0.050	Δρ_max = 3.04 e Å⁻³
S = 2.37	Δρ_min = −2.62 e Å⁻³
2428 reflections	Extinction correction: B-C type 1 Gaussian isotropic (Becker & Coppens, 1974)
78 parameters	Extinction coefficient: 0.19 (5)

Crystal data top

As₂Au_0.973Gd	β = 90.01 (3)°
M_r = 498.7	V = 162.82 (9) Å³
Monoclinic, P21/m(α0γ)00†	Z = 2
q = 0.03000a* + 0.48000c*	Mo Kα radiation
a = 3.9570 (8) Å	µ = 83.84 mm⁻¹
b = 4.060 (2) Å	T = 293 K
c = 10.135 (2) Å	0.31 × 0.06 × 0.0025 mm

† Symmetry operations: (1) x₁, x₂, x₃, x₄; (2) −x₁, 1/2+x₂, −x₃, −x₄; (3) −x₁, −x₂, −x₃, −x₄; (4) x₁, 1/2−x₂, x₃, x₄.

Data collection top

STOE IPDS 2 diffractometer	2428 independent reflections
Absorption correction: numerical (Jana2000; Petricek, Dusek & Palatinus, 2000)	1634 reflections with I > 3σ(I)
T_min = 0.064, T_max = 0.807	R_int = 0.077
9508 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.046	78 parameters
wR(F²) = 0.050	Δρ_max = 3.04 e Å⁻³
S = 2.37	Δρ_min = −2.62 e Å⁻³
2428 reflections

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

	x	y	z	U_iso*/U_eq	Occ. (<1)
Gd	0.2519 (4)	0.25	0.76613 (5)	0.0129 (3)
Au	0.7492 (4)	0.25	0.5006 (3)	0.0197 (3)	0.973 (3)
As1	0.2590 (10)	0.25	0.31231 (13)	0.0137 (6)
As2	0.7511 (12)	0.25	0.9981 (6)	0.0188 (7)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Gd	0.0189 (7)	0.0075 (5)	0.0122 (2)	0	−0.0056 (8)	0
Au	0.0250 (6)	0.0154 (5)	0.0186 (2)	0	−0.0049 (8)	0
As1	0.0165 (13)	0.0090 (12)	0.0157 (5)	0	−0.0073 (13)	0
As2	0.0248 (14)	0.0225 (13)	0.0090 (6)	0	−0.0028 (17)	0

Bond lengths (Å) top

	Average	Minimum	Maximum
Gd—Auⁱ	3.347 (4)	3.342 (4)	3.352 (4)
Gd—Au	3.335 (4)	3.310 (4)	3.359 (4)
Gd—Auⁱⁱ	3.381 (4)	3.366 (4)	3.395 (4)
Gd—Auⁱⁱⁱ	3.381 (4)	3.366 (4)	3.395 (4)
Gd—As1^iv	2.973 (4)	2.970 (4)	2.977 (4)
Gd—As1^v	2.973 (4)	2.970 (4)	2.977 (4)
Gd—As1ⁱⁱ	2.915 (4)	2.908 (4)	2.922 (4)
Gd—As1ⁱⁱⁱ	2.915 (4)	2.908 (4)	2.922 (4)
Gd—As2ⁱ	3.074 (8)	3.003 (9)	3.148 (9)
Gd—As2	3.071 (8)	3.038 (9)	3.104 (9)
Gd—As2^vi	3.140 (8)	3.112 (8)	3.174 (8)
Gd—As2^vii	3.140 (8)	3.112 (8)	3.174 (8)
Au—Auⁱⁱ	2.8304 (19)	2.8244 (19)	2.8364 (19)
Au—Auⁱⁱⁱ	2.8304 (19)	2.8244 (19)	2.8364 (19)
Au—Au^viii	2.8391 (19)	2.8337 (19)	2.8444 (19)
Au—Au^ix	2.8391 (19)	2.8337 (19)	2.8444 (19)
Au—As1	2.720 (6)	2.716 (6)	2.725 (6)
Au—As1^x	2.777 (6)	2.750 (6)	2.804 (6)
Au—As1ⁱⁱ	2.779 (5)	2.763 (5)	2.794 (5)
Au—As1ⁱⁱⁱ	2.779 (5)	2.763 (5)	2.794 (5)
As1—As2^xi	3.769 (10)	3.686 (11)	3.856 (11)
As1—As2^xii	3.734 (10)	3.593 (11)	3.881 (11)
As2—As2^vi	2.848 (5)	2.641 (5)	3.058 (6)
As2—As2^vii	2.848 (5)	2.641 (5)	3.058 (6)
As2—As2^xiii	2.831 (5)	2.632 (5)	3.044 (6)
As2—As2^xiv	2.831 (5)	2.632 (5)	3.044 (6)

Symmetry codes: (i) x₁−1, x₂, x₃, x₄; (ii) −x₁+1, −x₂, −x₃+1, −x₄; (iii) −x₁+1, −x₂+1, −x₃+1, −x₄; (iv) −x₁, −x₂, −x₃+1, −x₄; (v) −x₁, −x₂+1, −x₃+1, −x₄; (vi) −x₁+1, −x₂, −x₃+2, −x₄; (vii) −x₁+1, −x₂+1, −x₃+2, −x₄; (viii) −x₁+2, −x₂, −x₃+1, −x₄; (ix) −x₁+2, −x₂+1, −x₃+1, −x₄; (x) x₁+1, x₂, x₃, x₄; (xi) x₁−1, x₂, x₃−1, x₄; (xii) x₁, x₂, x₃−1, x₄; (xiii) −x₁+2, −x₂, −x₃+2, −x₄; (xiv) −x₁+2, −x₂+1, −x₃+2, −x₄.

(III) top

Crystal data top

As₂Au_0.966Tb	F(000) = 415
M_r = 499.0	D_x = 10.166 Mg m⁻³
Monoclinic, P21/m(α0γ)00†	Mo Kα radiation, λ = 0.71073 Å
q = 0.02000a* + 0.46000c*	Cell parameters from 7354 reflections
a = 3.933 (2) Å	θ = 3.0–33.4°
b = 4.0891 (15) Å	µ = 84.78 mm⁻¹
c = 10.1350 (14) Å	T = 293 K
β = 90.0 (3)°	Platelet, black
V = 163.01 (12) Å³	0.13 × 0.12 × 0.01 mm
Z = 2

† Symmetry operations: (1) x₁, x₂, x₃, x₄; (2) −x₁, 1/2+x₂, −x₃, −x₄; (3) −x₁, −x₂, −x₃, −x₄; (4) x₁, 1/2−x₂, x₃, x₄.

Data collection top

STOE IPDS 2 diffractometer	2101 independent reflections
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus	1092 reflections with I > 3σ(I)
Plane graphite monochromator	R_int = 0.059
Detector resolution: 6.67 pixels mm^-1	θ_max = 33.4°, θ_min = 3.0°
ω scans	h = −5→6
Absorption correction: numerical (Jana2000; Petricek, Dusek & Palatinus, 2000)	k = −5→6
T_min = 0.066, T_max = 0.892	l = −16→16
9845 measured reflections

Refinement top

Refinement on F	Weighting scheme based on measured s.u.'s w = 1/(σ²(F) + 0.0001F²)
R[F² > 2σ(F²)] = 0.056	(Δ/σ)_max = 0.034
wR(F²) = 0.066	Δρ_max = 3.84 e Å⁻³
S = 2.96	Δρ_min = −3.65 e Å⁻³
2101 reflections	Extinction correction: B-C type 1 Lorentzian isotropic (Becker & Coppens, 1974)
78 parameters	Extinction coefficient: 0.26 (3)

Crystal data top

As₂Au_0.966Tb	β = 90.0 (3)°
M_r = 499.0	V = 163.01 (12) Å³
Monoclinic, P21/m(α0γ)00†	Z = 2
q = 0.02000a* + 0.46000c*	Mo Kα radiation
a = 3.933 (2) Å	µ = 84.78 mm⁻¹
b = 4.0891 (15) Å	T = 293 K
c = 10.1350 (14) Å	0.13 × 0.12 × 0.01 mm

† Symmetry operations: (1) x₁, x₂, x₃, x₄; (2) −x₁, 1/2+x₂, −x₃, −x₄; (3) −x₁, −x₂, −x₃, −x₄; (4) x₁, 1/2−x₂, x₃, x₄.

Data collection top

STOE IPDS 2 diffractometer	2101 independent reflections
Absorption correction: numerical (Jana2000; Petricek, Dusek & Palatinus, 2000)	1092 reflections with I > 3σ(I)
T_min = 0.066, T_max = 0.892	R_int = 0.059
9845 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.056	78 parameters
wR(F²) = 0.066	Δρ_max = 3.84 e Å⁻³
S = 2.96	Δρ_min = −3.65 e Å⁻³
2101 reflections

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

	x	y	z	U_iso*/U_eq	Occ. (<1)
Au1	0.7484 (10)	0.25	0.50072 (17)	0.0259 (3)	0.968 (4)
As1	0.2667 (16)	0.25	0.31004 (18)	0.0174 (6)
As2	0.751 (3)	0.25	0.9982 (4)	0.0246 (8)
Tb1	0.2494 (8)	0.25	0.76696 (6)	0.0179 (3)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Au1	0.0256 (6)	0.0250 (6)	0.0271 (3)	0	−0.001 (2)	0
As1	0.0138 (13)	0.0155 (11)	0.0229 (5)	0	−0.0045 (19)	0
As2	0.0315 (18)	0.0253 (15)	0.0170 (5)	0	−0.002 (4)	0
Tb1	0.0173 (6)	0.0167 (6)	0.0198 (2)	0	0.0004 (19)	0

Bond lengths (Å) top

	Average	Minimum	Maximum
Au1—Au1ⁱ	2.829 (4)	2.826 (4)	2.831 (4)
Au1—Au1ⁱⁱ	2.829 (4)	2.826 (4)	2.831 (4)
Au1—Au1ⁱⁱⁱ	2.845 (4)	2.843 (4)	2.848 (4)
Au1—Au1^iv	2.845 (4)	2.843 (4)	2.848 (4)
Au1—As1	2.707 (8)	2.684 (8)	2.729 (8)
Au1—As1^v	2.809 (8)	2.779 (8)	2.839 (8)
Au1—As1ⁱ	2.804 (5)	2.778 (5)	2.830 (5)
Au1—As1ⁱⁱ	2.804 (5)	2.778 (5)	2.830 (5)
Au1—Tb1	3.337 (5)	3.319 (5)	3.354 (5)
Au1—Tb1^v	3.341 (5)	3.333 (5)	3.349 (5)
Au1—Tb1ⁱ	3.397 (4)	3.385 (4)	3.409 (4)
Au1—Tb1ⁱⁱ	3.397 (4)	3.385 (4)	3.409 (4)
As1—As2^vi	3.757 (11)	3.666 (12)	3.848 (12)
As1—As2^vii	3.690 (11)	3.648 (12)	3.735 (12)
As1—Tb1^viii	2.985 (6)	2.974 (6)	2.996 (6)
As1—Tb1^ix	2.985 (6)	2.974 (6)	2.996 (6)
As1—Tb1ⁱ	2.901 (6)	2.897 (6)	2.904 (6)
As1—Tb1ⁱⁱ	2.901 (6)	2.897 (6)	2.904 (6)
As2—As2^x	2.844 (12)	2.725 (11)	2.962 (13)
As2—As2^xi	2.844 (12)	2.725 (11)	2.962 (13)
As2—As2^xii	2.833 (12)	2.717 (11)	2.954 (12)
As2—As2^xiii	2.833 (12)	2.717 (11)	2.954 (12)
As2—Tb1	3.063 (10)	3.026 (11)	3.100 (11)
As2—Tb1^v	3.056 (10)	3.029 (11)	3.085 (11)
As2—Tb1^x	3.139 (6)	3.135 (6)	3.141 (7)
As2—Tb1^xi	3.139 (6)	3.135 (6)	3.141 (7)

Symmetry codes: (i) −x₁+1, −x₂, −x₃+1, −x₄; (ii) −x₁+1, −x₂+1, −x₃+1, −x₄; (iii) −x₁+2, −x₂, −x₃+1, −x₄; (iv) −x₁+2, −x₂+1, −x₃+1, −x₄; (v) x₁+1, x₂, x₃, x₄; (vi) x₁−1, x₂, x₃−1, x₄; (vii) x₁, x₂, x₃−1, x₄; (viii) −x₁, −x₂, −x₃+1, −x₄; (ix) −x₁, −x₂+1, −x₃+1, −x₄; (x) −x₁+1, −x₂, −x₃+2, −x₄; (xi) −x₁+1, −x₂+1, −x₃+2, −x₄; (xii) −x₁+2, −x₂, −x₃+2, −x₄; (xiii) −x₁+2, −x₂+1, −x₃+2, −x₄.

Experimental details

	(I)	(II)	(III)
Crystal data
Chemical formula	As₂CuGd	As₂Au_0.973Gd	As₂Au_0.966Tb
M_r	370.6	498.7	499.0
Crystal system, space group	Monoclinic, P21/m(α0γ)00†	Monoclinic, P21/m(α0γ)00‡	Monoclinic, P21/m(α0γ)00§
Temperature (K)	293	293	293
Wave vectors	q = 0.03570a* + 0.47900c*	q = 0.03000a* + 0.48000c*	q = 0.02000a* + 0.46000c*
a, b, c (Å)	3.9041 (8), 3.9015 (8), 9.908 (2)	3.9570 (8), 4.060 (2), 10.135 (2)	3.933 (2), 4.0891 (15), 10.1350 (14)
β (°)	90, 90.05 (3), 90	90, 90.01 (3), 90	90, 90.0 (3), 90
V (Å³)	150.92 (5)	162.82 (9)	163.01 (12)
Z	2	2	2
Radiation type	Mo Kα	Mo Kα	Mo Kα
µ (mm⁻¹)	50.25	83.84	84.78
Crystal size (mm)	0.26 × 0.06 × 0.02	0.31 × 0.06 × 0.0025	0.13 × 0.12 × 0.01

Data collection
Diffractometer	STOE IPDS 2 diffractometer	STOE IPDS 2 diffractometer	STOE IPDS 2 diffractometer
Absorption correction	Numerical (Jana2000; Petricek, Dusek & Palatinus, 2000)	Numerical (Jana2000; Petricek, Dusek & Palatinus, 2000)	Numerical (Jana2000; Petricek, Dusek & Palatinus, 2000)
T_min, T_max	0.128, 0.460	0.064, 0.807	0.066, 0.892
No. of measured, independent and observed [I > 3σ(I)] reflections	10072, 2043, 751	9508, 2428, 1634	9845, 2101, 1092
R_int	0.094	0.077	0.059
(sin θ/λ)_max (Å⁻¹)	0.790	0.782	0.775

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.039, 0.039, 1.24	0.046, 0.050, 2.37	0.056, 0.066, 2.96
No. of reflections	2043	2428	2101
No. of parameters	77	78	78
No. of restraints	?	?	?
Δρ_max, Δρ_min (e Å⁻³)	1.64, −1.97	3.04, −2.62	3.84, −3.65

† Symmetry operations: (1) x₁, x₂, x₃, x₄; (2) −x₁, 1/2+x₂, −x₃, −x₄; (3) −x₁, −x₂, −x₃, −x₄; (4) x₁, 1/2−x₂, x₃, x₄.

‡ Symmetry operations: (1) x₁, x₂, x₃, x₄; (2) −x₁, 1/2+x₂, −x₃, −x₄; (3) −x₁, −x₂, −x₃, −x₄; (4) x₁, 1/2−x₂, x₃, x₄.

§ Symmetry operations: (1) x₁, x₂, x₃, x₄; (2) −x₁, 1/2+x₂, −x₃, −x₄; (3) −x₁, −x₂, −x₃, −x₄; (4) x₁, 1/2−x₂, x₃, x₄.

Computer programs: X-AREA, STOE, 2006, X-AREA, STOE, 2002, SHELXS97 (Sheldrick, 1997), Jana2000 (Petricek, Dusek & Palatinus, 2000), DIAMOND-Visuelles Informationssystem für Kristallstrukturen

(G. Bergerhoff, Bonn, 1999).

Selected bond lengths (Å) for (I) top

	Average	Minimum	Maximum
Gd—Cuⁱ	3.253 (6)	3.239 (6)	3.268 (6)
Gd—Cu	3.236 (6)	3.213 (6)	3.260 (6)
Gd—Cuⁱⁱ	3.242 (5)	3.228 (5)	3.255 (5)
Gd—Cuⁱⁱⁱ	3.242 (5)	3.228 (5)	3.255 (5)
Gd—As1^iv	2.948 (3)	2.945 (3)	2.951 (3)
Gd—As1^v	2.948 (3)	2.945 (3)	2.951 (3)
Gd—As1ⁱⁱ	2.938 (3)	2.934 (3)	2.943 (3)
Gd—As1ⁱⁱⁱ	2.938 (3)	2.934 (3)	2.943 (3)
Gd—As2ⁱ	3.082 (5)	3.017 (5)	3.145 (5)
Gd—As2	3.042 (5)	3.026 (5)	3.059 (5)
Gd—As2^vi	3.070 (4)	3.037 (4)	3.107 (4)
Gd—As2^vii	3.070 (4)	3.037 (4)	3.107 (4)
Cu—Cuⁱⁱ	2.726 (5)	2.724 (5)	2.728 (5)
Cu—Cuⁱⁱⁱ	2.726 (5)	2.724 (5)	2.728 (5)
Cu—Cu^viii	2.794 (5)	2.787 (5)	2.801 (5)
Cu—Cu^ix	2.794 (5)	2.787 (5)	2.801 (5)
Cu—As1	2.471 (7)	2.464 (7)	2.478 (7)
Cu—As1^x	2.535 (7)	2.521 (7)	2.548 (7)
Cu—As1ⁱⁱ	2.503 (5)	2.492 (5)	2.515 (5)
Cu—As1ⁱⁱⁱ	2.503 (5)	2.492 (5)	2.515 (5)
As2—As2^vi	2.705 (5)	2.568 (4)	2.850 (5)
As2—As2^vii	2.705 (5)	2.568 (4)	2.850 (5)
As2—As2^xi	2.820 (5)	2.675 (5)	2.967 (5)
As2—As2^xii	2.820 (5)	2.675 (5)	2.967 (5)

Selected bond lengths (Å) for (II) top

	Average	Minimum	Maximum
Gd—Auⁱ	3.347 (4)	3.342 (4)	3.352 (4)
Gd—Au	3.335 (4)	3.310 (4)	3.359 (4)
Gd—Auⁱⁱ	3.381 (4)	3.366 (4)	3.395 (4)
Gd—Auⁱⁱⁱ	3.381 (4)	3.366 (4)	3.395 (4)
Gd—As1^iv	2.973 (4)	2.970 (4)	2.977 (4)
Gd—As1^v	2.973 (4)	2.970 (4)	2.977 (4)
Gd—As1ⁱⁱ	2.915 (4)	2.908 (4)	2.922 (4)
Gd—As1ⁱⁱⁱ	2.915 (4)	2.908 (4)	2.922 (4)
Gd—As2ⁱ	3.074 (8)	3.003 (9)	3.148 (9)
Gd—As2	3.071 (8)	3.038 (9)	3.104 (9)
Gd—As2^vi	3.140 (8)	3.112 (8)	3.174 (8)
Gd—As2^vii	3.140 (8)	3.112 (8)	3.174 (8)
Au—Auⁱⁱ	2.8304 (19)	2.8244 (19)	2.8364 (19)
Au—Auⁱⁱⁱ	2.8304 (19)	2.8244 (19)	2.8364 (19)
Au—Au^viii	2.8391 (19)	2.8337 (19)	2.8444 (19)
Au—Au^ix	2.8391 (19)	2.8337 (19)	2.8444 (19)
Au—As1	2.720 (6)	2.716 (6)	2.725 (6)
Au—As1^x	2.777 (6)	2.750 (6)	2.804 (6)
Au—As1ⁱⁱ	2.779 (5)	2.763 (5)	2.794 (5)
Au—As1ⁱⁱⁱ	2.779 (5)	2.763 (5)	2.794 (5)
As1—As2^xi	3.769 (10)	3.686 (11)	3.856 (11)
As1—As2^xii	3.734 (10)	3.593 (11)	3.881 (11)
As2—As2^vi	2.848 (5)	2.641 (5)	3.058 (6)
As2—As2^vii	2.848 (5)	2.641 (5)	3.058 (6)
As2—As2^xiii	2.831 (5)	2.632 (5)	3.044 (6)
As2—As2^xiv	2.831 (5)	2.632 (5)	3.044 (6)

Symmetry codes: (i) x₁−1, x₂, x₃, x₄; (ii) −x₁+1, −x₂, −x₃+1, −x₄; (iii) −x₁+1, −x₂+1, −x₃+1, −x₄; (iv) −x₁, −x₂, −x₃+1, −x₄; (v) −x₁, −x₂+1, −x₃+1, −x₄; (vi) −x₁+1, −x₂, −x₃+2, −x₄; (vii) −x₁+1, −x₂+1, −x₃+2, −x₄; (viii) −x₁+2, −x₂, −x₃+1, −x₄; (ix) −x₁+2, −x₂+1, −x₃+1, −x₄; (x) x₁+1, x₂, x₃, x₄; (xi) x₁−1, x₂, x₃−1, x₄; (xii) x₁, x₂, x₃−1, x₄; (xiii) −x₁+2, −x₂, −x₃+2, −x₄; (xiv) −x₁+2, −x₂+1, −x₃+2, −x₄.

Selected bond lengths (Å) for (III) top

	Average	Minimum	Maximum
Au1—Au1ⁱ	2.829 (4)	2.826 (4)	2.831 (4)
Au1—Au1ⁱⁱ	2.829 (4)	2.826 (4)	2.831 (4)
Au1—Au1ⁱⁱⁱ	2.845 (4)	2.843 (4)	2.848 (4)
Au1—Au1^iv	2.845 (4)	2.843 (4)	2.848 (4)
Au1—As1	2.707 (8)	2.684 (8)	2.729 (8)
Au1—As1^v	2.809 (8)	2.779 (8)	2.839 (8)
Au1—As1ⁱ	2.804 (5)	2.778 (5)	2.830 (5)
Au1—As1ⁱⁱ	2.804 (5)	2.778 (5)	2.830 (5)
Au1—Tb1	3.337 (5)	3.319 (5)	3.354 (5)
Au1—Tb1^v	3.341 (5)	3.333 (5)	3.349 (5)
Au1—Tb1ⁱ	3.397 (4)	3.385 (4)	3.409 (4)
Au1—Tb1ⁱⁱ	3.397 (4)	3.385 (4)	3.409 (4)
As1—As2^vi	3.757 (11)	3.666 (12)	3.848 (12)
As1—As2^vii	3.690 (11)	3.648 (12)	3.735 (12)
As1—Tb1^viii	2.985 (6)	2.974 (6)	2.996 (6)
As1—Tb1^ix	2.985 (6)	2.974 (6)	2.996 (6)
As1—Tb1ⁱ	2.901 (6)	2.897 (6)	2.904 (6)
As1—Tb1ⁱⁱ	2.901 (6)	2.897 (6)	2.904 (6)
As2—As2^x	2.844 (12)	2.725 (11)	2.962 (13)
As2—As2^xi	2.844 (12)	2.725 (11)	2.962 (13)
As2—As2^xii	2.833 (12)	2.717 (11)	2.954 (12)
As2—As2^xiii	2.833 (12)	2.717 (11)	2.954 (12)
As2—Tb1	3.063 (10)	3.026 (11)	3.100 (11)
As2—Tb1^v	3.056 (10)	3.029 (11)	3.085 (11)
As2—Tb1^x	3.139 (6)	3.135 (6)	3.141 (7)
As2—Tb1^xi	3.139 (6)	3.135 (6)	3.141 (7)

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