Kesterite-type compound semiconductors, containing copper and zinc, have photovoltaic properties depending on cation distribution in the crystal structure. Anomalous diffraction allows discrimination of isoelectronic cations, in principle allowing a straightforward determination of site occupation factors from data collected at multiple energies close to the X-ray absorption edges of copper and zinc. However, extremely strong correlation between structural parameters precludes this. We present a recipe based on the direct dependency between refined occupation factors and atomic scattering power, which allows to lift the correlations and to detect issues of individual diffraction patterns or assumptions in the model, thereby allowing for reliable quantitative analysis of the Cu/Zn distribution.

The crystal structure of citalopram hydrobromide has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory techniques. Citalopram hydrobromide crystallizes in space group P21/c (#14) with a = 10.766 45(6), b = 33.070 86(16), c = 10.892 85(5) Å, β = 90.8518(3)°, V = 3878.03(4) Å3, and Z = 8. N–H⋯Br hydrogen bonds are important to the structure, but the crystal energy is dominated by van der Waals attraction. The powder pattern was submitted to International Centre for Diffraction Data for inclusion in the Powder Diffraction File™.

The Rietveld method based on X-ray diffraction (XRD) technology has been commonly applied for the quantitative analysis of crystalline minerals in organic-rich rocks. The presence of organic matter, however, has interference in varying degree to the quantitative result. In this work, the mixed samples of organic matter and crystalline minerals at given proportions were prepared to investigate the effect of organic matter on the Rietveld quantitative analysis of crystalline minerals in coal gangue. The relative standard deviation (RSD) and absolute error (AE) were used to evaluate the precision and accuracy of the quantitative result. The results showed that the presence of organic matter led to a reduction in the precision and accuracy. It was attributed in part to the presence of organic matter, which can produce a background noise in the XRD pattern, especially in the region of 5–30° (2θ). Further results showed that the interference in this region increased with the increase in the organic matter content. The RSD and AE were within the range of 10% and 2%, respectively, when the organic matter content is <30 wt%. Based on this, an approximate method for the Rietveld quantitative analysis of crystalline minerals in coal gangue was established.

Quantitative phase analysis (QPA) using neutron powder diffraction more often than not involves non-ambient studies where no sample preparation is possible. The larger samples and penetration of neutrons versus X-rays makes neutron diffraction less susceptible to inhomogeneity and large grain sizes, but most well-characterized QPA standard samples do not have these characteristics. Sample #4 from the International Union of Crystallography Commission on Powder Diffraction QPA round robin was one such sample. Data were collected using the POWGEN time-of-flight (TOF) neutron powder diffractometer and analysed together with historical data from the C2 diffractometer at Chalk River. The presence of magnetic reflections from Fe3O4 (magnetite) in the sample was an additional consideration, and given the frequency at which iron-containing and other magnetic compounds are present during in-operando studies their possible impact on the accuracy of QPA is of interest. Additionally, scattering from thermal diffuse scattering in the high-Q region (<0.6 Å) accessible with TOF data could impact QPA results during least-squares because of the extreme peak overlaps present in this region. Refinement of POWGEN data was largely insensitive to the modification of longer d-spacing reflections by magnetic contributions, but the constant-wavelength data were adversely impacted if the magnetic structure was not included. A robust refinement weighting was found to be effective in reducing quantification errors using the constant-wavelength neutron data both where intensities from magnetic reflections were ignored and included. Results from the TOF data were very sensitive to inadequate modelling of the high-Q (low d-spacing) background using simple polynomials.

In this investigation, the ability of Rietveld refinement method was used to simultaneously refine the structure and microstructure and evaluate the linear defects of cubic crystals. To do this, the basis of Stephans theory, about the anisotropic strain broadening, was developed and the values of dislocation density as well as the fraction of dislocation types were estimated. The reliability of this procedure was checked by selecting four different nanocrystaslline samples and evaluating the microstructure of these materials. Finally, the results were compared with those extracted from the whole powder pattern modeling method. Good agreement was achieved between the results of two methods.

The crystal structure of trandolapril has been solved by parallel tempering using the FOX software package with laboratory powder diffraction data submitted to and published in the Powder Diffraction File. Rietveld refinement was performed with the software package GSAS yielding orthorhombic lattice parameters of a = 19.7685(4), b = 15.0697(4), and c = 7.6704(2) Å (C24H34N2O5, Z = 4, space group P212121). The Rietveld refinement results were compared with density functional theory (DFT) calculations performed with CRYSTAL14. While the structures are similar, discrepancies are observed in the configuration of the octahydroindole ring between the Rietveld and DFT structures, suggesting the refined and calculated molecules are diastereomers.

The National Institute of Standards and Technology (NIST) certifies a suite of Standard Reference Materials (SRMs) to address specific aspects of the performance of X-ray powder diffraction instruments. This report describes SRM 1878b, the third generation of this powder diffraction SRM. SRM 1878b is intended for use in the preparation of calibration standards for the quantitative analyses of α-quartz by X-ray powder diffraction in accordance to National Institute for Occupational Safety and Health Analytical Method 7500, or equivalent. A unit of SRM 1878b consists of approximately 5 g of α-quartz powder bottled in an argon atmosphere. It is certified with respect to crystalline phase purity, or amorphous phase content, and lattice parameter. Neutron powder diffraction, both time of flight and constant wavelength, was used to certify the phase purity using SRM 676a as an internal standard. A NIST-built diffractometer, incorporating many advanced design features was used for certification measurements for lattice parameters.

A method to obtain both one-dimensional powder diffraction intensities I(2θ) and statistical uncertainties σ(2θ) from the data collected with a flat two-dimensional X-ray detector is proposed. The method has been applied to analysis of the diffraction data of fine quartz powder recorded with synchrotron X-ray. The profile and magnitude of the estimated uncertainties σ(2θ) have shown that the effects of propagation of the errors in 2θ are dominant as the uncertainties about the observed intensity values I(2θ). The powder diffraction intensity data I(2θ), including nine reflection peaks have been analyzed by the Rietveld method incorporating the experimentally estimated uncertainties σ(2θ). The observed I(2θ) data have been reproduced with a symmetric peak profile function (R wp = 0.84 %), and no significant peak shifts from calculated locations have been detected as compared with the experimental errors. The optimized values of the lattice constants of the quartz sample have nominally been estimated at a = 4.9131(4) Å and c = 5.4043(2) Å, where the uncertainties in parentheses are evaluated by the Rietveld optimization based on the estimated uncertainties σ(2θ) for intensities I(2θ). It is likely that reliability of error estimation about unit-cell dimensions has been improved by this analytical method.

The structures and powder X-ray reference diffraction patterns of the “natural superlattice” series Bi1−x Pbx OCuSe (x = 0, 0.02, 0.04, 0.06, 0.08, and 0.10) have been investigated. As the ionic radius of Pb2+ is greater than that of Bi3+, the unit-cell volume of Bi1−x Pbx OCuSe increases progressively from x = 0 to 0.1, namely, from 137.868(5) to 139.172(11) Å3, as expected. The structure of Bi1−x Pbx OCuSe is built from [Bi2(1−x)Pb2x O2]2(1−x)+ layers normal to the c-axis alternating with [Cu2Se2]2(1−x)− fluorite-like layers. Pb substitution in the Bi site of Bi1−x Pbx OCuSe leads to the weakening of the “bonding” between the [Bi2(1−x)Pb2x O2]2(1−x)+ and the [Cu2Se2]2(1−x)− layers. Powder patterns of Bi1−x Pbx OCuSe were submitted to be included in the Powder Diffraction File.

Two different crystalline structures corresponding to a zinc adipate and a zinc succinate were determined combining: X-ray powder and single-crystal diffraction, infrared spectroscopy, thermal analysis, and true densities experiments. The zinc succinate crystal structure was determined by single-crystal X-ray diffraction. This compound crystallizes in the orthorhombic space-group Cccm with unit-cell parameters a = 4.792(1) Å, b = 21.204(6) Å, c = 6.691(2) Å, V = 679.8(3) Å3, and Z = 8. Zinc adipate crystal structure was refined from the laboratory X-ray powder diffraction data by the Rietveld method. It crystallizes in the monoclinic space group P2/c with unit-cell parameters, a = 16.2037(17)Å, b = 4.7810(2)Å, c = 9.2692(6)Å, β = 90.329(3)°, V = 718.07(9) Å3, and Z = 4. The thermal expansion of it was estimated in 5.40 × 10−5 K−1. This contribution is a step on the way to systematize the regularities in the coordination diversity between linear dicarboxylates and transition metal–inorganic buildings units of metal–organic frameworks.

The title compound, the 4-phenyl-6-(trifluoromethyl)-3,4-dihydroquinolin-2(1H)-one (4) with chemical formula: (C16H12F3NO), was synthesized from N-[4-(trifluoromethyl)phenyl]cinnamamide (3), chemical formula: (C16H12F3NO), through an intramolecular cyclization mediated by triflic acid. Preliminary molecular characterization of both compounds was performed by Fourier transform infrared spectroscopy, gas chromatography mass spectrometry, and nuclear magnetic resonance spectroscopy (1H, 13C); crystallographic characterization was completed by X-ray diffraction of polycrystalline samples. The title compound 4 crystallized in a monoclinic system and unit-cell parameters are reported [a = 16.002 (3), b = 5.170 (1), c = 17.733 (3) Å, β = 111.11 (2)°, unit-cell volume V = 1368.5 (3) Å3, Z = 4] P21/c (No. 14) space group; the title compound 3 crystallized in a monoclinic system and unit-cell parameters are reported [a = 12.902 (2), b = 5.144 (1), c = 20.513 (5) Å, β = 91.67 (2)°, unit-cell volume V = 1360.7 (4) Å3, Z = 4] P21/c (No. 14) space group.

A new quaternary compound AlCeCo2Ni2 was synthesized and studied by means of X-ray powder diffraction technique. The powder pattern of AlCeCo2Ni2 was indexed and refined, giving a hexagonal structure, space group P6/mmm (No. 191) with the CaCu5 structure type. a = 4.9242(2) Å, c = 4.0524(1) Å, V = 85.1 Å3, Z = 1, ρx = 7.85 g cm−3, F30 = 130.2(0.010, 30), and RIR = 0.71(2).

N-acylamino acid isomers: ortho, meta, and para-methylhippuric acids, are specific xylene metabolites. Here, we report X-ray powder diffraction data, unit-cell parameters, and space groups for the three isomer (C10H11NO3), [ortho-methylhippuric acid 2 mHA, monoclinic P21/n cell, a = 8.522(1), b = 10.443(1), c = 10.734(1) Å, β = 92.43(1)°, V = 954.5(1) Å3; meta-methylhippuric acid 3 mHA, monoclinic C2/c cell a = 20.0951(2), b = 10.485(1), c = 10.074(2) Å, β = 119.08(1)°, V = 1933.9(1) Å3; para-methylhippuric acid 4 mHA, orthorhombic P212121 cell, a = 5.1794(7), b = 8.279(1), c = 22.276(2) Å, V = 955.2(2) Å3], space group. In each case, all measured diffraction peaks were indexed and are consistent with the corresponding space group.

X-ray powder diffraction (XRPD) data for Palbociclib, C24H29N7O2, are reported [a = 18.182(2) Å, b = 11.508(1) Å, c = 5.041(1) Å, α = 81.282(7)°, β = 97.423(7)°, γ = 102.415(2)°, unit-cell volume V = 1013.1(4) Å3, Z = 2, and space group P-1. All XRPD measured lines were indexed and no detectable impurities were observed.