Determination of the Exact Orientation of Single-Crystal X-ray Optics from Its Glitch Spectrum and Modeling of Glitches for an Arbitrary Configuration

X-ray optics made of single-crystal materials are widely used at most of the X-ray sources due to the outstanding properties. The main drawback of such optics—the diffraction losses, also known as glitches of intensity in the energy spectrum of the transmitted/diffracted beam. To be able to handle this negative effect, one needs a reliable way to simulate the glitch spectrum in any configuration. Here, we demonstrate the way of precisely determining the crystallographic orientation and unit cell parameters of optical elements just from a small glitch spectrum with the consequent possibility of simulating glitches for any energy.

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Refinement of the crystal structure of sieleckiite and revision of its symmetry

Mineralogical Magazine ◽

10.1180/minmag.2016.080.143 ◽

2017 ◽

Vol 81 (4) ◽

pp. 917-922

Author(s):

Peter Elliott

Keyword(s):

Crystal Structure ◽

Synchrotron Radiation ◽

Single Crystal ◽

Diffraction Data ◽

X Ray Diffraction ◽

Aluminium Phosphate ◽

Unit Cell Parameters ◽

X Ray ◽

Cell Parameters ◽

Phosphate Mineral

AbstractThe crystal structure of the copper aluminium phosphate mineral sieleckiite, Cu3Al4(PO4)2 (OH)12·2H2O, from the Mt Oxide copper mine, Queensland, Australia was solved from single-crystal X-ray diffraction data utilizing synchrotron radiation. Sieleckiite has monoclinic rather than triclinic symmetry as previously reported and is space group C2/m with unit-cell parameters a = 11.711(2), b = 6.9233(14), c = 9.828(2) Å, β = 92.88(3)°, V = 795.8(3) Å3and Z = 2. The crystal structure, which has been refined to R1 = 0.0456 on the basis of 1186 unique reflections with Fo > 4σF, is a framework of corner-, edge- and face- sharing Cu and Al octahedra and PO4 tetrahedra.

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D'ansite-(Mn), Na21Mn2+(SO4)10Cl3 and d'ansite-(Fe), Na21Fe2+(SO4)10Cl3, two new minerals from volcanic fumaroles

Mineralogical Magazine ◽

10.1180/minmag.2012.076.7.10 ◽

2012 ◽

Vol 76 (7) ◽

pp. 2773-2783 ◽

Cited By ~ 5

Author(s):

F. Demartin ◽

I. Campostrini ◽

C. Castellano ◽

C. M. Gramaccioli ◽

M. Russo

Keyword(s):

Single Crystal ◽

Empirical Formula ◽

Energy Dispersive Spectrometry ◽

Chemical Analyses ◽

Crystal Data ◽

Unit Cell Parameters ◽

Single Crystal Diffraction ◽

X Ray ◽

Cell Parameters ◽

Fossa Crater

AbstractThe new minerals d'ansite-(Mn), Na21Mn2+(SO4)10Cl3, and d'ansite-(Fe), Na21Fe2+(SO4)10Cl3, occur as encrustations in fumaroles at Vesuvius, Naples, Italy and La Fossa crater, Vulcano, Aeolian Islands, Italy, respectively. Both minerals are cubic and crystallize in space group I3d. D'ansite-(Mn) forms colourless translucent tristetrahedral crystals up to 0.2 mm on edge; d'ansite-(Fe) forms aggregates of colourless to white complex isometric crystals of about the same size. Chemical analyses obtained by energy-dispersive spectrometry on an electron microprobe gave the following mean compositions: d'ansite-(Mn), Na2O 39.37, MnO 3.46, MgO 0.13, SO3 49.99, Cl 6.36, O=Cl–1.44, total 97.87 wt.%, corresponding to an empirical formula, on the basis of 43 anions, of Na20.61 (Mn2+0.79Mg0.05)Σ0.84S10.13O40.09Cl2.91; and d'ansite-(Fe), Na2O 39.12, FeO 4.18, MgO 0.12, SO3 49.91, Cl 6.81, O=Cl –1.54, total 98.60 wt.%, corresponding to an empirical formula of Na20.42(Fe2+0.94Mg0.05)Σ0.99S10.08O39.89Cl3.11. The six strongest reflections in the X-ray powder diffraction pattern of d'ansite-(Fe) [listed as dobs(Å) (I) (hkl)] are as follows: 2.807(100)(044), 2.570(37)(235), 1.714(29)(129), 3.384(27)(233), 3.113(26)(134), 2.108(15)(237). The unit-cell parameters obtained from single-crystal data are 15.9291(9) and 15.882(3) Å for d'ansite-(Mn) and d'ansite-(Fe), respectively. The structure of both minerals was refined, using single-crystal diffraction data, to final R parameters of 0.0309 and 0.0336 on reflections with I > 2σ(I). The structure contains three independent Na sites, one of which is partially occupied by Mn2+ or Fe2+, two independent sulfate anions and one chlorine site.

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Layer stacking disorder in Mg-Fe chlorites based on powder X-ray diffraction data

American Mineralogist ◽

10.2138/am-2020-6982 ◽

2020 ◽

Vol 105 (3) ◽

pp. 353-362

Author(s):

Katarzyna Luberda-Durnaś ◽

Marek Szczerba ◽

Małgorzata Lempart ◽

Zuzanna Ciesielska ◽

Arkadiusz Derkowski

Keyword(s):

Accurate Determination ◽

Unit Cell ◽

Powder Xrd ◽

X Ray Diffraction ◽

Unit Cell Parameters ◽

Xrd Pattern ◽

X Ray ◽

Cell Parameters ◽

Layer Stacking

Abstract The primary aim of this study was the accurate determination of unit-cell parameters and description of disorder in chlorites with semi-random stacking using common X-ray diffraction (XRD) data for bulk powder samples. In the case of ordered chlorite structures, comprehensive crystallographic information can be obtained based on powder XRD data. Problems arise for samples with semi-random stacking, where due to strong broadening of hkl peaks with k ≠ 3n, the determination of unit-cell parameters is demanding. In this study a complete set of information about the stacking sequences in chlorite structures was determined based on XRD pattern simulation, which included determining a fraction of layers shifted by ±1/3b, interstratification with different polytypes and 2:1 layer rotations. A carefully selected series of pure Mg-Fe tri-trioctahedral chlorites with iron content in the range from 0.1 to 3.9 atoms per half formula unit cell was used in the study. In addition, powder XRD patterns were carefully investigated for the broadening of the odd-number basal reflections to determine interstratification of 14 and 7 Å layers. These type of interstratifications were finally not found in any of the samples. This result was also confirmed by the XRD pattern simulations, assuming interstratification with R0 ordering. Based on h0l XRD reflections, all the studied chlorites were found to be the IIbb polytype with a monoclinic-shaped unit cell (β ≈ 97°). For three samples, the hkl reflections with k ≠ 3n were partially resolvable; therefore, a conventional indexing procedure was applied. Two of the chlorites were found to have a monoclinic cell (with α, γ = 90°). Nevertheless, among all the samples, the more general triclinic (pseudomonoclinic) crystal system with symmetry C1 was assumed, to calculate unit-cell parameters using Le Bail fitting. A detailed study of semi-random stacking sequences shows that simple consideration of the proportion of IIb-2 and IIb-4/6 polytypes, assuming equal content of IIb-4 and IIb-6, is not sufficient to fully model the stacking structure in chlorites. Several, more general, possible models were therefore considered. In the first approach, a parameter describing a shift into one of the ±1/3b directions (thus, the proportion of IIb-4 and IIb-6 polytypes) was refined. In the second approach, for samples with slightly distinguishable hkl reflections with k ≠ 3n, some kind of segregation of individual polytypes (IIb-2/4/6) was considered. In the third approach, a model with rotations of 2:1 layers about 0°, 120°, 240° was shown to have the lowest number of parameters to be optimized and therefore give the most reliable fits. In all of the studied samples, interstratification of different polytypes was revealed with the fraction of polytypes being different than IIbb ranging from 5 to 19%, as confirmed by fitting of h0l XRD reflections.

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Single-crystal X-ray diffraction, EMPA, FTIR and X-ray photoelectron spectroscopy study of narsarsukite from Murun Massif, Russia

Mineralogical Magazine ◽

10.1180/minmag.2016.080.135 ◽

2017 ◽

Vol 81 (2) ◽

pp. 339-354 ◽

Cited By ~ 2

Author(s):

E. Schingaro ◽

E. Mesto ◽

M. Lacalamita ◽

F. Scordari ◽

E. Kaneva ◽

...

Keyword(s):

Single Crystal ◽

Photoelectron Spectroscopy ◽

Chemical Study ◽

Structural Disorder ◽

Crystal Chemical ◽

X Ray Diffraction ◽

Unit Cell Parameters ◽

X Ray ◽

Cell Parameters ◽

Alkaline Massif

AbstractA crystal chemical study of narsarsukite from the Murun alkaline massif, Russia has been carried out combining single-crystal X-ray diffraction, electron microprobe analyses, micro-Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The narsarsukite single crystals are tetragonal (space group I4/m) with unit-cell parameters: 10.7140(1) ≤ a ≤ 10.7183(2) Å and 7.9478(1) ≤ c ≤ 7.9511(1) Å. The XPS analysis showed that Fe occurs in the mineral as Fe3+, whereas the FTIR spectrum showed that the sample studied is anhydrous. The average crystal chemical formula of the Murun narsarsukite is: Na2.04K0.01(V0.015+Ti0.74Zr0.01Al0.01Fe0.223+Mg0.01)1.00Si4.00(O10.74F0.23OH0.03)11.00. Structural disorder at octahedral and interstitial sites was modelled and also discussed in consideration of the main substitutional mechanism Ti4+ + O2– ↔ Fe3+ + (F–, OH–) active in the structure of the mineral.

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Crystal structure determination of non-stoichiometric Ca4−xRuO6−x (x = 1.17) from X-ray powder diffraction data

Powder Diffraction ◽

10.1017/s0885715615000883 ◽

2016 ◽

Vol 31 (1) ◽

pp. 59-62

Author(s):

Martin Etter ◽

Maximilian J. Krautloher ◽

Nakheon Sung ◽

Joel Bertinshaw ◽

Bumjoon Kim ◽

...

Keyword(s):

Crystal Structure ◽

Powder Diffraction ◽

Flux Growth ◽

Powder Diffraction Data ◽

Unit Cell Parameters ◽

X Ray ◽

Cell Parameters ◽

Growth Method ◽

Calcium Ruthenate

A new non-stoichiometric calcium ruthenate [Ca4−xRuO6−x with x = 1.17(1)] was synthesized by the flux growth method and characterized by the X-ray powder diffraction. The crystal structure is isostructural to the K4CdCl6 type with space group R$\bar 3$c. Unit-cell parameters are a = 9.2881(1), c = 11.1634(2) Å, V = 834.03(3) Å3, and Z = 6.

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Structure determination of anhydrous acid strontium oxalate by conventional X-ray powder diffraction

Powder Diffraction ◽

10.1154/1.1401199 ◽

2001 ◽

Vol 16 (4) ◽

pp. 224-226 ◽

Cited By ~ 2

Author(s):

G. Vanhoyland ◽

M. K. Van Bael ◽

J. Mullens ◽

L. C. Van Poucke

Keyword(s):

Thermal Decomposition ◽

Water Content ◽

Powder Diffraction ◽

Structure Determination ◽

Two Dimensional ◽

Unit Cell Parameters ◽

X Ray ◽

Cell Parameters ◽

Corrected Data

The anhydrous acid strontium oxalate Sr(HC2O4)⋅½(C2O4) was obtained by thermal decomposition of the hydrated acid strontium oxalate Sr(HC2O4)⋅½(C2O4)⋅H2O. This non-hygroscopic compound crystallizes in the space group P 21/c (No. 14) with unit cell parameters: a=0.796 61(7) nm, b=0.9205(1) nm, c=0.731 98(8) nm, and β=102.104(8)°. Final refinement of the X-ray powder data yielded RB=3.2% and Rwp=11.1% (background-corrected data). In this structure, Sr is eight-fold coordinated by O. These polyhedra are connected together by edge-sharing to form two-dimensional (2D) layers along the bc-plane, which means that there is an increased dimensionality from 1D to 2D with decreasing water content of the acid oxalates.

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X-ray Diffraction Study of the Crystal Structure of the Tl Ternary Chalcogenides Tl2x In2(1−x)Se2, x = 0.2, 0.3,...0.9

Acta Crystallographica Section B Structural Science ◽

10.1107/s0108768197017886 ◽

1998 ◽

Vol 54 (4) ◽

pp. 358-364 ◽

Cited By ~ 6

Author(s):

K. G. Hatzisymeon ◽

S. C. Kokkou ◽

A. N. Anagnostopoulos ◽

P. I. Rentzeperis

Keyword(s):

Crystal Structure ◽

Single Crystal ◽

Rietveld Method ◽

Direct Methods ◽

X Ray Diffraction ◽

Unit Cell Parameters ◽

Single Crystal Diffraction ◽

X Ray ◽

Cell Parameters ◽

Volume Decrease

A series of thallium ternary chalcogenides with the composition Tl2x In2(1−x)Se2, x = 0.2, 0.3,...0.9, have been studied by X-ray powder and, for some of them, single-crystal diffraction. They are tetragonal, space group I4/mcm, Z = 4, and isostructural with the binary semiconductor TlSe. Their crystal structures have been solved by direct methods and refined by the Rietveld method to a precision which is satisfactorily comparable to single-crystal results. As x is changed from x = 0.2 to x = 0.9 the unit-cell parameters and volume decrease or increase following Kurnakov's law, which is valid for solid solutions. Refined positional parameters of Se, In—Se and Tl—Se bond lengths vary with x also according to the same law. The distribution of In and Tl cations in 4(a) and 4(b) sites depends on the stoichiometry x and the crystals are composed of [In3+Se2]_{\infty}^- chains along the c axis in which InSe4 tetrahedra share edges; the chains are interconnected with Tl+(In+) ions.

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Molecular and crystal structure of a copper(II) complex of sildenafil

Zeitschrift für Naturforschung B ◽

10.1515/znb-2021-0145 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Akhmatkhodja N. Yunuskhodjayev ◽

Shokhista F. Iskandarova ◽

Vahobjon Kh. Sabirov

Keyword(s):

Crystal Structure ◽

Single Crystal ◽

Unit Cell ◽

Monoclinic Space Group ◽

X Ray Diffraction ◽

Unit Cell Parameters ◽

Piperazine Ring ◽

Space Group ◽

X Ray ◽

Cell Parameters

Abstract The crystal structure of a copper(II) complex of protonated sildenafil, CuCl3C22H31N6O4S⋅2H2O was studied by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P21/n with the unit cell parameters a = 15.4292(2), b = 9.06735(12), c = 21.1752(2) Å, V = 2945.48(7) Å3, Z = 4. The Cu atom is coordinated by the sildenafil ligand via the N2 atom of the pyrazolopyrimidine ring and by three chloride anions. Sildenafil is protonated at the methylated N6 atom of the piperazine ring and it is cation ligand with a 1+ charge.

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Reactions between Co(II), 1,2-bis(diphenylphosphino)ethane, and NaBH3CN in the presence and absence of CO. The crystal structure of bis(cyanotrihydroborato)tetrakis(N,N-dimethylformamide)cobalt(II)

Canadian Journal of Chemistry ◽

10.1139/v88-285 ◽

1988 ◽

Vol 66 (7) ◽

pp. 1770-1775 ◽

Cited By ~ 7

Author(s):

David J. Elliot ◽

Sanna Haukilahti ◽

David G. Holah ◽

Alan N. Hughes ◽

Stanislaw Maciaszek ◽

...

Keyword(s):

Crystal Structure ◽

Single Crystal ◽

Unit Cell ◽

X Ray Diffraction ◽

Unit Cell Parameters ◽

Triclinic Space Group ◽

Space Group ◽

X Ray ◽

Cell Parameters ◽

R Factor

Reactions between Co(II), Diphos, and NaBH3CN lead to Co(BH3CN)2(Diphos)2, 1, or [Co(BH3CN)(Diphos)2]X, 2 (X = ClO4 or BPh4), and, in certain solvents, 2 reacts to produce [Co(CN)(Diphos)2](ClO4). Compound 1 can be reversibly converted to Co(BH3CN)2(DMF)4, 4, via Co(BH3CN)2(Diphos)(DMF). In addition, 1 reacts with CO to form the Co(I) and Co(III) compounds [Co(Diphos)2](CO)]X and [Co(Diphos)2(CN)2]X (X = BH3CN or BPh4). Single crystal X-ray diffraction studies of 4 show that the compound crystallizes in the triclinic space group [Formula: see text], with unit cell parameters a = 7.572(6), b = 9.695(6), c = 9.395(6) Å, α = 81.06(4), β = 68.46(5), γ = 68.19(5)°, V = 595.5 Å3, Z = 1, and dcalcd = 1.202 g cm−3. The structure converged to a conventional R factor of 0.040 for 2841 observations and showed an octahedral arrangement of four O atoms from DMF molecules and two trans N-bound BH3CN groups around the Co(II) center.

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