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Single crystals of the title compound, ytterbium silver silicide, were synthesized from the corresponding elements using a eutectic Ag/Si mixture as a solvent. Structure determination suggested the composition of the product to be YbAgxSi2−x [x = 0.28 (1)], i.e. a new ternary derivative of the α-ThSi2 structure type, which crystallizes in the body-centered tetragonal space group I41/amd. The two atoms in the asymmetric unit lie on special positions with Wyckoff symbols 4a (Yb), and 8e (disordered Ag and Si).
Supporting information
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (Please check) = 0.000 Å
- R factor = 0.009
- wR factor = 0.020
- Data-to-parameter ratio = 13.1
checkCIF/PLATON results
No syntax errors found
Alert level C
PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings Differ .... ?
PLAT045_ALERT_1_C Calculated and Reported Z Differ by ............ 0.25 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 ......................... 10.00 Perc.
0 ALERT level A = In general: serious problem
0 ALERT level B = Potentially serious problem
5 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
1 ALERT type 4 Improvement, methodology, query or suggestion
Data collection: SMART (Bruker, 2002); cell refinement: SMART; data reduction: SAINT (Bruker, 2002); program(s) used to solve structure: SHELXTL (Sheldrick, 2001); program(s) used to refine structure: SHELXTL; molecular graphics: XP in SHELXTL; software used to prepare material for publication: SHELXTL.
ytterbium silver silicide
top
Crystal data top
YbAg.28Si1.72 | Dx = 7.091 Mg m−3 |
Mr = 251.76 | Mo Kα radiation, λ = 0.71073 Å |
Tetragonal, I41/amd | Cell parameters from 796 reflections |
Hall symbol: -I 4bd 2 | θ = 5.2–30.9° |
a = 4.0757 (2) Å | µ = 42.37 mm−1 |
c = 14.1965 (11) Å | T = 293 K |
V = 235.82 (2) Å3 | Bar, grey |
Z = 4 | 0.05 × 0.04 × 0.03 mm |
F(000) = 429 | |
Data collection top
Bruker APEX SMART diffractometer | 118 independent reflections |
Radiation source: fine-focus sealed tube | 107 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.018 |
Detector resolution: 8.3 pixels mm-1 | θmax = 30.9°, θmin = 5.2° |
ω scans | h = −5→5 |
Absorption correction: multi-scan (SADABS; Sheldrick, 2003) | k = −5→4 |
Tmin = 0.155, Tmax = 0.280 | l = −20→19 |
796 measured reflections | |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.009 | w = 1/[σ2(Fo2) + (0.0097P)2 + 0.0681P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.020 | (Δ/σ)max < 0.001 |
S = 1.23 | Δρmax = 0.45 e Å−3 |
118 reflections | Δρmin = −0.66 e Å−3 |
9 parameters | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
0 restraints | Extinction coefficient: 0.0086 (6) |
Special details top
Experimental. Data collection was performed with four batch runs at φ = 0.00 ° (606 frames),
at φ = 90.00 ° (606 frames), at φ = 180.00 ° (606 frames), and at φ =
270.00 (606 frames). Frame width = 0.30 \& in ω. Data was merged, corrected
for decay, and treated with multi-scan absorption corrections. Structure was
solved readily using direct methods and refined on F2 using the
SHELXL package (Sheldrick, 2001). |
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 (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
Yb | 0.0000 | 0.7500 | 0.1250 | 0.00700 (14) | |
Si | 0.0000 | 0.2500 | 0.29237 (6) | 0.0077 (4) | 0.858 (4) |
Ag | 0.0000 | 0.2500 | 0.29237 (6) | 0.0077 (4) | 0.142 (4) |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Yb | 0.00575 (15) | 0.00575 (15) | 0.00951 (17) | 0.000 | 0.000 | 0.000 |
Si | 0.0044 (5) | 0.0145 (6) | 0.0041 (4) | 0.000 | 0.000 | 0.000 |
Ag | 0.0044 (5) | 0.0145 (6) | 0.0041 (4) | 0.000 | 0.000 | 0.000 |
Geometric parameters (Å, º) top
Yb—Agi | 3.1116 (3) | Si—Agix | 2.3463 (16) |
Yb—Agii | 3.1116 (3) | Si—Siix | 2.3463 (16) |
Yb—Sii | 3.1116 (3) | Si—Agiv | 2.3664 (8) |
Yb—Siii | 3.1116 (3) | Si—Siiv | 2.3664 (8) |
Yb—Agiii | 3.1116 (3) | Si—Agviii | 2.3664 (8) |
Yb—Agiv | 3.1116 (3) | Si—Siviii | 2.3664 (8) |
Yb—Siiii | 3.1116 (3) | Si—Ybii | 3.1116 (3) |
Yb—Siiv | 3.1116 (3) | Si—Ybiv | 3.1116 (3) |
Yb—Agv | 3.1116 (3) | Si—Ybvii | 3.1116 (3) |
Yb—Agvi | 3.1116 (3) | Si—Ybviii | 3.1116 (3) |
Yb—Agvii | 3.1116 (3) | Si—Ybx | 3.1302 (6) |
Yb—Agviii | 3.1116 (3) | | |
| | | |
Agi—Yb—Agii | 180.00 (3) | Agvi—Yb—Agviii | 44.30 (3) |
Agi—Yb—Sii | 0.00 (3) | Agvii—Yb—Agviii | 135.70 (3) |
Agii—Yb—Sii | 180.0 | Agix—Si—Agiv | 120.55 (3) |
Agi—Yb—Siii | 180.00 (3) | Siix—Si—Agiv | 120.55 (3) |
Agii—Yb—Siii | 0.00 (3) | Siix—Si—Siiv | 120.55 (3) |
Sii—Yb—Siii | 180.00 (3) | Agix—Si—Agviii | 120.55 (3) |
Agi—Yb—Agiii | 135.70 (3) | Siix—Si—Agviii | 120.55 (3) |
Agii—Yb—Agiii | 44.30 (3) | Agiv—Si—Agviii | 118.90 (7) |
Sii—Yb—Agiii | 135.70 (3) | Siiv—Si—Agviii | 118.90 (7) |
Siii—Yb—Agiii | 44.30 (3) | Agix—Si—Siviii | 120.55 (3) |
Agi—Yb—Agiv | 44.30 (3) | Siix—Si—Siviii | 120.55 (3) |
Agii—Yb—Agiv | 135.70 (3) | Agiv—Si—Siviii | 118.90 (7) |
Sii—Yb—Agiv | 44.30 (3) | Siiv—Si—Siviii | 118.90 (7) |
Siii—Yb—Agiv | 135.70 (3) | Agix—Si—Ybii | 67.851 (14) |
Agiii—Yb—Agiv | 180.0 | Siix—Si—Ybii | 67.851 (14) |
Agi—Yb—Siiii | 135.70 (3) | Agiv—Si—Ybii | 139.082 (6) |
Agii—Yb—Siiii | 44.30 (3) | Siiv—Si—Ybii | 139.082 (6) |
Sii—Yb—Siiii | 135.70 (3) | Agviii—Si—Ybii | 68.139 (14) |
Siii—Yb—Siiii | 44.30 (3) | Siviii—Si—Ybii | 68.139 (14) |
Agiii—Yb—Siiii | 0.00 (3) | Agix—Si—Ybiv | 67.851 (14) |
Agiv—Yb—Siiii | 180.0 | Siix—Si—Ybiv | 67.851 (14) |
Agi—Yb—Siiv | 44.30 (3) | Agiv—Si—Ybiv | 68.139 (14) |
Agii—Yb—Siiv | 135.70 (3) | Siiv—Si—Ybiv | 68.139 (14) |
Sii—Yb—Siiv | 44.30 (3) | Agviii—Si—Ybiv | 139.082 (6) |
Siii—Yb—Siiv | 135.70 (3) | Siviii—Si—Ybiv | 139.082 (6) |
Agiii—Yb—Siiv | 180.0 | Ybii—Si—Ybiv | 135.70 (3) |
Agiv—Yb—Siiv | 0.0 | Agix—Si—Ybvii | 67.851 (14) |
Siiii—Yb—Siiv | 180.0 | Siix—Si—Ybvii | 67.851 (14) |
Agi—Yb—Agv | 81.828 (10) | Agiv—Si—Ybvii | 68.139 (14) |
Agii—Yb—Agv | 98.172 (10) | Siiv—Si—Ybvii | 68.139 (14) |
Sii—Yb—Agv | 81.828 (10) | Agviii—Si—Ybvii | 139.082 (6) |
Siii—Yb—Agv | 98.172 (10) | Siviii—Si—Ybvii | 139.082 (6) |
Agiii—Yb—Agv | 81.828 (10) | Ybii—Si—Ybvii | 81.828 (10) |
Agiv—Yb—Agv | 98.172 (10) | Ybiv—Si—Ybvii | 81.828 (10) |
Siiii—Yb—Agv | 81.828 (10) | Agix—Si—Ybviii | 67.851 (14) |
Siiv—Yb—Agv | 98.172 (10) | Siix—Si—Ybviii | 67.851 (14) |
Agi—Yb—Agvi | 81.828 (10) | Agiv—Si—Ybviii | 139.082 (6) |
Agii—Yb—Agvi | 98.172 (10) | Siiv—Si—Ybviii | 139.082 (6) |
Sii—Yb—Agvi | 81.828 (10) | Agviii—Si—Ybviii | 68.139 (14) |
Siii—Yb—Agvi | 98.172 (10) | Siviii—Si—Ybviii | 68.139 (14) |
Agiii—Yb—Agvi | 81.828 (10) | Ybii—Si—Ybviii | 81.828 (10) |
Agiv—Yb—Agvi | 98.172 (10) | Ybiv—Si—Ybviii | 81.828 (10) |
Siiii—Yb—Agvi | 81.828 (10) | Ybvii—Si—Ybviii | 135.70 (3) |
Siiv—Yb—Agvi | 98.172 (10) | Agix—Si—Ybx | 139.381 (10) |
Agv—Yb—Agvi | 135.70 (3) | Siix—Si—Ybx | 139.381 (10) |
Agi—Yb—Agvii | 98.172 (10) | Agiv—Si—Ybx | 67.30 (3) |
Agii—Yb—Agvii | 81.828 (10) | Siiv—Si—Ybx | 67.30 (3) |
Sii—Yb—Agvii | 98.172 (10) | Agviii—Si—Ybx | 67.30 (3) |
Siii—Yb—Agvii | 81.828 (10) | Siviii—Si—Ybx | 67.30 (3) |
Agiii—Yb—Agvii | 98.172 (10) | Ybii—Si—Ybx | 135.443 (14) |
Agiv—Yb—Agvii | 81.828 (10) | Ybiv—Si—Ybx | 81.941 (6) |
Siiii—Yb—Agvii | 98.172 (10) | Ybvii—Si—Ybx | 135.443 (14) |
Siiv—Yb—Agvii | 81.828 (10) | Ybviii—Si—Ybx | 81.941 (6) |
Agv—Yb—Agvii | 44.30 (3) | Agix—Si—Yb | 139.381 (10) |
Agvi—Yb—Agvii | 180.0 | Siix—Si—Yb | 139.381 (10) |
Agi—Yb—Agviii | 98.172 (10) | Agiv—Si—Yb | 67.30 (3) |
Agii—Yb—Agviii | 81.828 (10) | Siiv—Si—Yb | 67.30 (3) |
Sii—Yb—Agviii | 98.172 (10) | Agviii—Si—Yb | 67.30 (3) |
Siii—Yb—Agviii | 81.828 (10) | Siviii—Si—Yb | 67.30 (3) |
Agiii—Yb—Agviii | 98.172 (10) | Ybii—Si—Yb | 81.941 (6) |
Agiv—Yb—Agviii | 81.828 (10) | Ybiv—Si—Yb | 135.443 (14) |
Siiii—Yb—Agviii | 98.172 (10) | Ybvii—Si—Yb | 81.941 (6) |
Siiv—Yb—Agviii | 81.828 (10) | Ybviii—Si—Yb | 135.443 (14) |
Agv—Yb—Agviii | 180.00 (3) | Ybx—Si—Yb | 81.24 (2) |
Symmetry codes: (i) −y−1/4, x+1/4, z−1/4; (ii) −x+1/2, −y+3/2, −z+1/2; (iii) −y+3/4, x+5/4, z−1/4; (iv) −x−1/2, −y+1/2, −z+1/2; (v) −y−1/4, x+5/4, z−1/4; (vi) −y+3/4, x+1/4, z−1/4; (vii) −x−1/2, −y+3/2, −z+1/2; (viii) −x+1/2, −y+1/2, −z+1/2; (ix) y−1/4, −x+1/4, −z+3/4; (x) x, y−1, z. |
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