Uranium copper dianti­monide, UCu_0.44(1)Sb₂ with a large Cu deficiency

UCu_0.44 (1)Sb₂, synthesized in the presence of an Sb flux, crystallizes in the ZrCuSi₂-type structure, but with a partial occupancy of the Cu site.

Key indicators

• Single-crystal X-ray study
• T = 120 K
• Mean [sigma]() = 0.000 Å
• Disorder in main residue
• R factor = 0.023
• wR factor = 0.051
• Data-to-parameter ratio = 10.3

checkCIF/PLATON results

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Alert level C
PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings    Differ ....          ?
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT045_ALERT_1_C Calculated and Reported Z Differ by ............       0.50 Ratio
PLAT068_ALERT_1_C Reported F000 Differs from Calcd (or Missing)...          ?
PLAT077_ALERT_4_C Unitcell contains non-integer number of atoms ..          ?
PLAT301_ALERT_3_C Main Residue  Disorder .........................      16.00 Perc.

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   6 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   4 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

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 structure: SHELXTL (Sheldrick, 2001); molecular graphics: XP in SHELXTL; software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).

Uranium copper diantimonide

Crystal data

UCu0.44Sb2	Dx = 9.840 Mg m^−3
Mr = 509.49	Mo Kα radiation, λ = 0.71073 Å
Tetragonal, P4/nmm	Cell parameters from 1295 reflections
Hall symbol: -P 4a 2a	θ = 2.2–26.3°
a = 4.3289 (8) Å	µ = 64.92 mm^−1
c = 9.176 (3) Å	T = 120 K
V = 171.95 (7) Å^3	Bar, grey
Z = 2	0.06 × 0.05 × 0.05 mm
F(000) = 414

Data collection

Bruker SMART APEX diffractometer	134 independent reflections
Radiation source: fine-focus sealed tube	134 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.030
Detector resolution: 8.3 pixels mm^-1	θmax = 26.3°, θmin = 2.2°
ω scans	h = −5→5
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	k = −5→5
Tmin = 0.040, Tmax = 0.053	l = −11→10
1295 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.023	w = 1/[σ^2(Fo^2) + (0.0229P)^2 + 1.0837P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.051	(Δ/σ)max < 0.001
S = 1.42	Δρmax = 1.27 e Å^−3
134 reflections	Δρmin = −1.90 e Å^−3
13 parameters	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.0221 (18)

Special details

Experimental. Data collection is performed with four batch runs at φ = 0.00 ° (450 frames), at φ = 90.00 ° (450 frames), at φ = 180.00 ° (250 frames), and at φ = 270.00 (100 frames). Frame width = 0.40 \& in ω. Data are 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)
U	0.2500	0.2500	0.23744 (9)	0.0084 (4)
Sb1	0.7500	0.2500	0.5000	0.0076 (4)
Sb2	0.2500	0.2500	0.85145 (17)	0.0101 (5)
Cu	0.7500	0.2500	0.0000	0.005 (2)	0.441 (14)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
U	0.0061 (4)	0.0061 (4)	0.0131 (5)	0.000	0.000	0.000
Sb1	0.0061 (5)	0.0061 (5)	0.0106 (8)	0.000	0.000	0.000
Sb2	0.0060 (5)	0.0060 (5)	0.0182 (8)	0.000	0.000	0.000
Cu	0.004 (2)	0.004 (2)	0.007 (3)	0.000	0.000	0.000

Geometric parameters (Å, º)

U—Cu^i	3.0711 (8)	Sb1—U^vii	3.2387 (9)
U—Cu^ii	3.0711 (8)	Sb2—Cu^v	2.5579 (9)
U—Cu^iii	3.0711 (8)	Sb2—Cu^xi	2.5579 (9)
U—Cu	3.0711 (8)	Sb2—Cu^vii	2.5579 (9)
U—Sb2^iv	3.1678 (7)	Sb2—Cu^xii	2.5579 (9)
U—Sb2^v	3.1678 (7)	Sb2—U^iv	3.1678 (7)
U—Sb2^vi	3.1678 (7)	Sb2—U^v	3.1678 (7)
U—Sb2^vii	3.1678 (7)	Sb2—U^vii	3.1678 (7)
U—Sb1	3.2387 (9)	Sb2—U^vi	3.1678 (7)
U—Sb1^v	3.2387 (9)	Sb2—U^xi	3.542 (2)
U—Sb1^ii	3.2387 (9)	Cu—Sb2^v	2.5579 (9)
U—Sb1^vii	3.2387 (9)	Cu—Sb2^xiii	2.5579 (9)
Sb1—Sb1^viii	3.0610 (6)	Cu—Sb2^vii	2.5579 (9)
Sb1—Sb1^vii	3.0610 (6)	Cu—Sb2^xiv	2.5579 (9)
Sb1—Sb1^v	3.0610 (6)	Cu—U^i	3.0711 (8)
Sb1—Sb1^ix	3.0610 (6)	Cu—U^x	3.0711 (8)
Sb1—U^v	3.2387 (9)	Cu—U^iii	3.0711 (8)
Sb1—U^x	3.2387 (9)
Cu^i—U—Cu^ii	59.782 (18)	Sb1^ix—Sb1—U^v	118.201 (9)
Cu^i—U—Cu^iii	89.62 (3)	U—Sb1—U^v	123.598 (17)
Cu^ii—U—Cu^iii	59.782 (18)	Sb1^viii—Sb1—U^x	61.799 (9)
Cu^i—U—Cu	59.782 (18)	Sb1^vii—Sb1—U^x	118.201 (9)
Cu^ii—U—Cu	89.62 (3)	Sb1^v—Sb1—U^x	118.201 (9)
Cu^iii—U—Cu	59.782 (17)	Sb1^ix—Sb1—U^x	61.799 (9)
Cu^i—U—Sb2^iv	48.38 (2)	U—Sb1—U^x	83.87 (3)
Cu^ii—U—Sb2^iv	48.38 (2)	U^v—Sb1—U^x	123.598 (18)
Cu^iii—U—Sb2^iv	107.39 (3)	Sb1^viii—Sb1—U^vii	118.201 (9)
Cu—U—Sb2^iv	107.39 (3)	Sb1^vii—Sb1—U^vii	61.799 (9)
Cu^i—U—Sb2^v	107.39 (3)	Sb1^v—Sb1—U^vii	118.201 (9)
Cu^ii—U—Sb2^v	107.39 (3)	Sb1^ix—Sb1—U^vii	61.799 (8)
Cu^iii—U—Sb2^v	48.38 (2)	U—Sb1—U^vii	123.598 (17)
Cu—U—Sb2^v	48.38 (2)	U^v—Sb1—U^vii	83.87 (3)
Sb2^iv—U—Sb2^v	150.16 (6)	U^x—Sb1—U^vii	123.598 (17)
Cu^i—U—Sb2^vi	107.39 (3)	Cu^v—Sb2—Cu^xi	73.50 (3)
Cu^ii—U—Sb2^vi	48.38 (2)	Cu^v—Sb2—Cu^vii	115.60 (6)
Cu^iii—U—Sb2^vi	48.38 (2)	Cu^xi—Sb2—Cu^vii	73.50 (3)
Cu—U—Sb2^vi	107.39 (3)	Cu^v—Sb2—Cu^xii	73.50 (3)
Sb2^iv—U—Sb2^vi	86.198 (15)	Cu^xi—Sb2—Cu^xii	115.60 (6)
Sb2^v—U—Sb2^vi	86.198 (15)	Cu^vii—Sb2—Cu^xii	73.50 (3)
Cu^i—U—Sb2^vii	48.38 (2)	Cu^v—Sb2—U^iv	135.67 (2)
Cu^ii—U—Sb2^vii	107.39 (3)	Cu^xi—Sb2—U^iv	135.67 (2)
Cu^iii—U—Sb2^vii	107.39 (3)	Cu^vii—Sb2—U^iv	63.835 (15)
Cu—U—Sb2^vii	48.38 (2)	Cu^xii—Sb2—U^iv	63.835 (15)
Sb2^iv—U—Sb2^vii	86.198 (15)	Cu^v—Sb2—U^v	63.835 (15)
Sb2^v—U—Sb2^vii	86.198 (15)	Cu^xi—Sb2—U^v	63.835 (15)
Sb2^vi—U—Sb2^vii	150.16 (6)	Cu^vii—Sb2—U^v	135.67 (2)
Cu^i—U—Sb1	121.853 (13)	Cu^xii—Sb2—U^v	135.67 (2)
Cu^ii—U—Sb1	177.13 (2)	U^iv—Sb2—U^v	150.16 (6)
Cu^iii—U—Sb1	121.853 (13)	Cu^v—Sb2—U^vii	135.67 (2)
Cu—U—Sb1	93.25 (2)	Cu^xi—Sb2—U^vii	63.835 (15)
Sb2^iv—U—Sb1	130.40 (2)	Cu^vii—Sb2—U^vii	63.835 (15)
Sb2^v—U—Sb1	74.63 (3)	Cu^xii—Sb2—U^vii	135.67 (2)
Sb2^vi—U—Sb1	130.40 (2)	U^iv—Sb2—U^vii	86.198 (15)
Sb2^vii—U—Sb1	74.63 (3)	U^v—Sb2—U^vii	86.198 (15)
Cu^i—U—Sb1^v	177.13 (2)	Cu^v—Sb2—U^vi	63.835 (15)
Cu^ii—U—Sb1^v	121.853 (13)	Cu^xi—Sb2—U^vi	135.67 (2)
Cu^iii—U—Sb1^v	93.25 (2)	Cu^vii—Sb2—U^vi	135.67 (2)
Cu—U—Sb1^v	121.853 (13)	Cu^xii—Sb2—U^vi	63.835 (15)
Sb2^iv—U—Sb1^v	130.40 (2)	U^iv—Sb2—U^vi	86.198 (15)
Sb2^v—U—Sb1^v	74.63 (3)	U^v—Sb2—U^vi	86.198 (15)
Sb2^vi—U—Sb1^v	74.63 (3)	U^vii—Sb2—U^vi	150.16 (6)
Sb2^vii—U—Sb1^v	130.40 (2)	Cu^v—Sb2—U^xi	57.80 (3)
Sb1—U—Sb1^v	56.402 (17)	Cu^xi—Sb2—U^xi	57.80 (3)
Cu^i—U—Sb1^ii	121.853 (13)	Cu^vii—Sb2—U^xi	57.80 (3)
Cu^ii—U—Sb1^ii	93.25 (2)	Cu^xii—Sb2—U^xi	57.80 (3)
Cu^iii—U—Sb1^ii	121.853 (13)	U^iv—Sb2—U^xi	104.92 (3)
Cu—U—Sb1^ii	177.13 (2)	U^v—Sb2—U^xi	104.92 (3)
Sb2^iv—U—Sb1^ii	74.63 (3)	U^vii—Sb2—U^xi	104.92 (3)
Sb2^v—U—Sb1^ii	130.40 (2)	U^vi—Sb2—U^xi	104.92 (3)
Sb2^vi—U—Sb1^ii	74.63 (3)	Sb2^v—Cu—Sb2^xiii	106.50 (3)
Sb2^vii—U—Sb1^ii	130.40 (2)	Sb2^v—Cu—Sb2^vii	115.60 (6)
Sb1—U—Sb1^ii	83.87 (3)	Sb2^xiii—Cu—Sb2^vii	106.50 (3)
Sb1^v—U—Sb1^ii	56.402 (17)	Sb2^v—Cu—Sb2^xiv	106.50 (3)
Cu^i—U—Sb1^vii	93.25 (2)	Sb2^xiii—Cu—Sb2^xiv	115.60 (6)
Cu^ii—U—Sb1^vii	121.853 (13)	Sb2^vii—Cu—Sb2^xiv	106.50 (3)
Cu^iii—U—Sb1^vii	177.13 (2)	Sb2^v—Cu—U^i	167.01 (3)
Cu—U—Sb1^vii	121.853 (12)	Sb2^xiii—Cu—U^i	67.79 (2)
Sb2^iv—U—Sb1^vii	74.63 (3)	Sb2^vii—Cu—U^i	77.39 (4)
Sb2^v—U—Sb1^vii	130.40 (2)	Sb2^xiv—Cu—U^i	67.79 (2)
Sb2^vi—U—Sb1^vii	130.40 (2)	Sb2^v—Cu—U^x	67.79 (2)
Sb2^vii—U—Sb1^vii	74.63 (3)	Sb2^xiii—Cu—U^x	167.01 (3)
Sb1—U—Sb1^vii	56.402 (17)	Sb2^vii—Cu—U^x	67.79 (2)
Sb1^v—U—Sb1^vii	83.87 (3)	Sb2^xiv—Cu—U^x	77.39 (4)
Sb1^ii—U—Sb1^vii	56.402 (17)	U^i—Cu—U^x	120.218 (17)
Sb1^viii—Sb1—Sb1^vii	180.0	Sb2^v—Cu—U^iii	77.39 (4)
Sb1^viii—Sb1—Sb1^v	90.0	Sb2^xiii—Cu—U^iii	67.79 (2)
Sb1^vii—Sb1—Sb1^v	90.0	Sb2^vii—Cu—U^iii	167.01 (3)
Sb1^viii—Sb1—Sb1^ix	90.0	Sb2^xiv—Cu—U^iii	67.79 (2)
Sb1^vii—Sb1—Sb1^ix	90.0	U^i—Cu—U^iii	89.62 (3)
Sb1^v—Sb1—Sb1^ix	180.0	U^x—Cu—U^iii	120.218 (18)
Sb1^viii—Sb1—U	118.201 (9)	Sb2^v—Cu—U	67.79 (2)
Sb1^vii—Sb1—U	61.799 (9)	Sb2^xiii—Cu—U	77.39 (4)
Sb1^v—Sb1—U	61.799 (9)	Sb2^vii—Cu—U	67.79 (2)
Sb1^ix—Sb1—U	118.201 (9)	Sb2^xiv—Cu—U	167.01 (3)
Sb1^viii—Sb1—U^v	61.799 (9)	U^i—Cu—U	120.218 (18)
Sb1^vii—Sb1—U^v	118.201 (9)	U^x—Cu—U	89.62 (3)
Sb1^v—Sb1—U^v	61.799 (9)	U^iii—Cu—U	120.218 (17)

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