Xenotime-type Yb[AsO₄]

Yb[AsO₄], ytterbium(III) oxoarsenate(V), adopts the xenotime structure type. Single crystals were obtained in an attempt to synthesize a compound with nominal composition Yb₃OCl[AsO₃]₂ by fusing a mixture of Yb₂O₃, YbCl₃ and As₂O₃ in a 4:1:3 molar ratio at 1123 K, owing to air-intrusion during the reaction. The structure is built up by chains of edge-sharing [YbO₈] trigonal dodeca­hedra and [AsO₄] tetra­hedra in a primitive rod packing. Yb and As are situated on positions with m2 symmetry, whereas O atoms are located on a mirror plane.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](s-O) = 0.002 Å
• R factor = 0.009
• wR factor = 0.023
• Data-to-parameter ratio = 9.5

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT021_ALERT_1_C Ratio Unique / Expected Reflections too High ...       1.02
PLAT088_ALERT_3_C Poor Data / Parameter Ratio ....................       9.50
PLAT199_ALERT_1_C Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_C Check the Reported _diffrn_ambient_temperature .        293 K

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

   3 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
   0 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: COLLECT (Nonius, 1998); cell refinement: SCALEPACK (Otwinowski & Minor, 1997); data reduction: SCALEPACK and DENZO (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 2005); software used to prepare material for publication: SHELXL97.

Ytterbium(III) Oxoarsenate(V)

Crystal data

Yb(AsO4)	Dx = 6.830 Mg m^−3
Mr = 311.96	Mo Kα radiation, λ = 0.71069 Å
Tetragonal, I41/amd	Cell parameters from 1512 reflections
Hall symbol: -I 4bd 2	θ = 4.4–28.3°
a = 6.9712 (4) Å	µ = 41.46 mm^−1
c = 6.2431 (4) Å	T = 293 K
V = 303.40 (3) Å^3	Block, colourless
Z = 4	0.07 × 0.06 × 0.04 mm
F(000) = 540

Data collection

Nonius KappaCCD diffractometer	114 independent reflections
Radiation source: fine-focus sealed tube	109 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.057
Detector resolution: 9 pixels mm^-1	θmax = 28.3°, θmin = 4.4°
φ and ω scans	h = −9→9
Absorption correction: numerical (X-SHAPE; Stoe & Cie, 1999)	k = −9→9
Tmin = 0.082, Tmax = 0.174	l = −8→8
2463 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)] = 0.009	w = 1/[σ^2(Fo^2) + (0.0136P)^2 + 0.1746P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.023	(Δ/σ)max < 0.001
S = 1.06	Δρmax = 1.13 e Å^−3
114 reflections	Δρmin = −0.56 e Å^−3
12 parameters	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.0122 (5)

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

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

	x	y	z	Uiso*/Ueq
Yb	0.0000	0.7500	0.1250	0.00581 (15)
As	0.0000	0.2500	0.3750	0.00456 (19)
O	0.0000	0.4329 (3)	0.1990 (3)	0.0101 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Yb	0.00622 (16)	0.00622 (16)	0.00497 (19)	0.000	0.000	0.000
As	0.0049 (3)	0.0049 (3)	0.0038 (3)	0.000	0.000	0.000
O	0.0149 (10)	0.0074 (9)	0.0080 (8)	0.000	0.000	0.0031 (8)

Geometric parameters (Å, º)

Yb—O	2.2584 (18)	Yb—As^v	3.1215 (2)
Yb—O^i	2.2584 (18)	Yb—Yb^ix	3.8191 (2)
Yb—O^ii	2.2584 (18)	Yb—Yb^v	3.8191 (2)
Yb—O^iii	2.2584 (18)	As—O^x	1.6831 (17)
Yb—O^iv	2.3910 (18)	As—O^xi	1.6831 (17)
Yb—O^v	2.3910 (18)	As—O^xii	1.6831 (17)
Yb—O^vi	2.3910 (18)	As—O	1.6831 (17)
Yb—O^vii	2.3910 (18)	As—Yb^viii	3.1216 (2)
Yb—As^viii	3.1215 (2)	As—Yb^v	3.1215 (2)
O—Yb—O^i	92.398 (18)	O^vi—Yb—As^v	147.78 (4)
O—Yb—O^ii	156.39 (9)	O^vii—Yb—As^v	32.22 (4)
O^i—Yb—O^ii	92.398 (18)	As^viii—Yb—As^v	180.0
O—Yb—O^iii	92.398 (18)	O—Yb—Yb^ix	85.205 (18)
O^i—Yb—O^iii	156.39 (9)	O^i—Yb—Yb^ix	167.68 (4)
O^ii—Yb—O^iii	92.398 (18)	O^ii—Yb—Yb^ix	85.205 (18)
O—Yb—O^iv	80.03 (4)	O^iii—Yb—Yb^ix	35.93 (4)
O^i—Yb—O^iv	134.03 (5)	O^iv—Yb—Yb^ix	33.66 (4)
O^ii—Yb—O^iv	80.03 (4)	O^v—Yb—Yb^ix	110.227 (10)
O^iii—Yb—O^iv	69.58 (7)	O^vi—Yb—Yb^ix	98.10 (4)
O—Yb—O^v	69.58 (7)	O^vii—Yb—Yb^ix	110.227 (10)
O^i—Yb—O^v	80.03 (4)	As^viii—Yb—Yb^ix	65.878 (2)
O^ii—Yb—O^v	134.03 (5)	As^v—Yb—Yb^ix	114.122 (2)
O^iii—Yb—O^v	80.03 (4)	O—Yb—Yb^v	35.93 (4)
O^iv—Yb—O^v	135.70 (5)	O^i—Yb—Yb^v	85.205 (18)
O—Yb—O^vi	80.03 (4)	O^ii—Yb—Yb^v	167.68 (4)
O^i—Yb—O^vi	69.58 (7)	O^iii—Yb—Yb^v	85.205 (18)
O^ii—Yb—O^vi	80.03 (4)	O^iv—Yb—Yb^v	110.227 (10)
O^iii—Yb—O^vi	134.03 (5)	O^v—Yb—Yb^v	33.66 (4)
O^iv—Yb—O^vi	64.45 (8)	O^vi—Yb—Yb^v	110.227 (10)
O^v—Yb—O^vi	135.70 (5)	O^vii—Yb—Yb^v	98.10 (4)
O—Yb—O^vii	134.03 (5)	As^viii—Yb—Yb^v	114.122 (2)
O^i—Yb—O^vii	80.03 (4)	As^v—Yb—Yb^v	65.878 (2)
O^ii—Yb—O^vii	69.58 (7)	Yb^ix—Yb—Yb^v	99.614 (1)
O^iii—Yb—O^vii	80.03 (4)	O^x—As—O^xi	115.23 (7)
O^iv—Yb—O^vii	135.70 (5)	O^x—As—O^xii	98.49 (12)
O^v—Yb—O^vii	64.45 (8)	O^xi—As—O^xii	115.23 (7)
O^vi—Yb—O^vii	135.70 (5)	O^x—As—O	115.23 (7)
O—Yb—As^viii	78.20 (4)	O^xi—As—O	98.49 (12)
O^i—Yb—As^viii	101.80 (4)	O^xii—As—O	115.23 (7)
O^ii—Yb—As^viii	78.20 (4)	O^x—As—Yb^viii	49.24 (6)
O^iii—Yb—As^viii	101.80 (4)	O^xi—As—Yb^viii	130.76 (6)
O^iv—Yb—As^viii	32.22 (4)	O^xii—As—Yb^viii	49.24 (6)
O^v—Yb—As^viii	147.78 (4)	O—As—Yb^viii	130.76 (6)
O^vi—Yb—As^viii	32.22 (4)	O^x—As—Yb^v	130.76 (6)
O^vii—Yb—As^viii	147.78 (4)	O^xi—As—Yb^v	49.24 (6)
O—Yb—As^v	101.80 (4)	O^xii—As—Yb^v	130.76 (6)
O^i—Yb—As^v	78.20 (4)	O—As—Yb^v	49.24 (6)
O^ii—Yb—As^v	101.80 (4)	Yb^viii—As—Yb^v	180.0
O^iii—Yb—As^v	78.20 (4)	As—O—Yb	151.05 (10)
O^iv—Yb—As^v	147.78 (4)	As—O—Yb^v	98.53 (8)
O^v—Yb—As^v	32.22 (4)	Yb—O—Yb^v	110.42 (7)

Symmetry codes: (i) y−3/4, x+3/4, −z+1/4; (ii) −x, −y+3/2, z; (iii) −y+3/4, x+3/4, −z+1/4; (iv) y−1/4, −x+3/4, z+1/4; (v) −x, −y+1, −z; (vi) −y+1/4, −x+3/4, z+1/4; (vii) x, y+1/2, −z; (viii) −x, −y+1, −z+1; (ix) −x+1/2, −y+3/2, −z+1/2; (x) y−1/4, x+1/4, −z+3/4; (xi) −x, −y+1/2, z; (xii) −y+1/4, x+1/4, −z+3/4.