The crystal structure of mupirocin Form I has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Mupirocin Form I crystallizes in space group P21 (#4) with a = 12.562 81(16), b = 5.103 63(4), c = 21.713 34(29) Å, β = 100.932(1)°, V = 1366.91(2) Å3, and Z = 2. Although the three hydroxyl groups and the carboxylic acid participate in a three-dimensional hydrogen bond network, the crystal energy appears to be dominated by van der Waals interactions. The Rietveld-refined and density functional optimized structures differ significantly. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™.

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.

Polycrystalline compounds of Dy0.55Sr0.45Mn1−xFexO3 (x = 0.0 and 0.20) were synthesized using ceramic method and characterized by X-ray powder diffraction technique using CuKα (1.5406 Å) radiation at room temperature. All the diffraction peaks were indexed to an orthorhombic cell with space group Pnma (#62). Whole powder diffraction profile refinement was performed using GSAS package.

This work deals with the determination of the mineralogical composition of three quartzite samples, selected as case study to verify the viability and accuracy of various experimental techniques commonly used in geometallurgy and petrography for the determination of the mineralogical composition of rock samples. The investigated samples are from the North-Eastern side of the Denali National Park (Alaska Range, USA). The mineralogical phase abundance of the samples was determined by digitally assisted optical modal point counting, scanning electron microscopy (SEM) + energy dispersive spectroscopy (EDS) modal and digital image analysis, normative calculation from bulk chemistry calculation, and modal Rietveld X-ray powder diffraction. The results of our study indicate that the results provided by modal optical and SEM digitalized counting seem less accurate than the others. The determination with EDS mapping was found to be inaccurate only for one sample. Agreement was found between the X-ray diffraction estimates and bulk chemistry calculation. For both modal optical and SEM digitalized counting, the statistics was probably insufficient to provide accurate results. The estimates obtained from the various methods are compared with each other in the attempt to attain general indications on the precision, accuracy, advantages/disadvantages of each method.

X-ray powder diffraction data for 5,6-dihydro-3-(4-morpholinyl)-1-[4-(2-oxo-1-piperidinyl)phenyl]-2(1H)-pyridinone, C20H25N3O3, are reported [a = 5.989(2), b = 6.669(3), c = 24.605(5)Å, α = 84.466(7)°, β = 89.859(6)°, γ = 69.074(4)°, unit-cell volume V = 913.11 Å3, Z = 2, and space group P−1]. No detectable impurities were observed.

This paper introduces a new method to determine the crystalline fraction in samples containing amorphous phases from experimental X-ray diffraction data. Computer generated codes, one for each measured data point, are used to interpret the pattern as to where diffraction peaks exist and what is the angular breadth of each peak's intensity above background. Two parameters are defined that are used to identify the position and intensity of the crystalline phase diffraction peaks. For mold fluxes used in continuous casting, the crystalline fraction of solid slag film is a key factor that can affect heat transfer between solidified shell and mold. In this work, a new method was developed to determine the crystallinity of solid slag films. This method does not require structure parameters or other references, and results can be obtained directly by reading a text file with diffraction data. Results indicate that, there is a positive correlation between crystalline fraction and integrated intensities corresponding to crystalline phases. The selection of integration interval does not have much effect on results. To simplify computations, 20–45°2θ was considered as an appropriate interval.

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.

Ion-exchanged Aurivillius materials form perovskite nanosheet booklets wherein well-defined bi-periodic sheets, with ~11.5 Å thickness, exhibit extensive stacking disorder. The perovskite layer contents were defined initially using combined synchrotron X-ray and neutron Rietveld refinement of the parent Aurivillius structure. The structure of the subsequently ion-exchanged material, which is disordered in its stacking sequence, is analyzed using both pair distribution function (PDF) analysis and recursive method simulations of the scattered intensity. Combined X-ray and neutron PDF refinement of supercell stacking models demonstrates sensitivity of the PDF to both perpendicular and transverse stacking vector components. Further, hierarchical ensembles of stacking models weighted by a standard normal distribution are demonstrated to improve PDF fit over 1–25 Å. Recursive method simulations of the X-ray scattering profile demonstrate agreement between the real space stacking analysis and more conventional reciprocal space methods. The local structure of the perovskite sheet is demonstrated to relax only slightly from the Aurivillius structure after ion exchange.

A polycrystalline sample of Ca4ZrGe3O12 was synthesized using the nitrate–citrate method and heated at 850–1100 °C. Structural refinement based on X-ray powder diffraction data showed that the crystal structure is of the garnet type with a cubic unit-cell parameter [a = 12.71299(3) Å] and the space group Ia$\bar 3$d. The structural formula is presented as Ca3[CaZr]octa[Ge]tetraO12.

The crystal structure of paliperidone has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Paliperidone crystallizes in space group P21/n (# 14) with a = 14.151 58(6), b = 21.537 80(9), c = 6.913 26(2) Å, β = 92.3176(2)°, V = 2105.396(13) Å3, and Z = 4. The unit-cell volume at 295 K is 1.5% larger than at 200 K, but the expansion is anisotropic; the b-axis is nearly constant at the two temperatures, while the a- and c-axes expand by 0.71 and 0.87%, respectively. There is only one significant hydrogen (H)-bond in the crystal structure. This H-bond is between the hydroxyl group O31–H58 and the ketone oxygen O25. The result is a chain along the c-axis with graph set C1,1(7). In addition to this H-bond, the molecular packing is dominated by van der Waals attractions. The powder pattern is included in the Powder Diffraction File™ as entry 00-064-1497.

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.

X-ray powder diffraction data, unit-cell parameters, and space group for tectoridin, C22H22O11, are reported [a = 13.577 (2) Å, b = 10.466 (8) Å, c = 9.454 (7) Å, α = 85.709 (4)°, β = 94.855 (3)°, γ = 101.485 (3)°, unit-cell volume V = 1309.50 Å3, Z = 2, ρ = 1.179 × 103 kg m−3, and space group P1]. No detectable impurity was observed.

The crystal structure of choline fenofibrate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Choline fenofibrate crystallizes in space group Pbca (#61) with a = 12.341 03(2), b = 28.568 70(6), c = 12.025 62(2) Å, V = 4239.84(1) Å3, and Z = 8. The hydroxyl group of the choline anion makes a strong hydrogen bond to the ionized carboxylate group of the fenofibrate anion. Together with C–H···O hydrogen bonds, these link the cations and anions into layers parallel to the ac-plane. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™.

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 (Rwp = 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.

X-ray powder diffraction data, unit-cell parameters, and space group for a new memantine analogue of a Platinum (Pt) (II) complex labelled LA-13, C12H24Cl2N2Pt, are reported [a = 8.324(1) Å, b = 27.838(2) Å, c = 7.113(1), β = 111.25(1), unit-cell volume V = 1536.26 Å3, Z = 4, and space group P21/n]. All measured lines were indexed and are consistent with the P21/n space group. No detectable impurity was observed.

X-ray powder diffraction data, unit-cell parameters, and space group for menthyl lactate, C13H24O3, are reported [a = 5.522(6) Å, b = 11.795(8) Å, c = 17.780(6) Å, α = 50.632(3)°, β = 90.000(0)°, γ = 117.632(4)°, unit-cell volume V = 716.392(0) Å3, Z = 2, and space group P−1]. All measured lines were indexed and no detectable impurities were observed.

The structures and powder X-ray reference diffraction patterns of the “natural superlattice” series Bi1−xPbxOCuSe (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−xPbxOCuSe increases progressively from x = 0 to 0.1, namely, from 137.868(5) to 139.172(11) Å3, as expected. The structure of Bi1−xPbxOCuSe is built from [Bi2(1−x)Pb2xO2]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−xPbxOCuSe leads to the weakening of the “bonding” between the [Bi2(1−x)Pb2xO2]2(1−x)+ and the [Cu2Se2]2(1−x)− layers. Powder patterns of Bi1−xPbxOCuSe were submitted to be included in the Powder Diffraction File.

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.

X-ray powder diffraction data, unit-cell parameters, and space group for deferasirox, C21H15N3O4, are reported [a = 8.821(7) Å, b = 26.798(2) Å, c = 7.540(4) Å, α = 90°, β = 94.655(2)°, γ = 90°, unit-cell volume V = 1776.7(3) Å3, Z = 4, ρcal = 1.396 g cm−3, and space group P21/c]. All measured lines were indexed and are consistent with the P21/c space group. No detectable impurity was observed.

The α-aminonitrile, 2-morpholino-2-(3,4,5-trimethoxyphenyl)acetonitrile (C15H20N2O4), was prepared through a silica sulfuric acid-catalyzed Strecker reaction between 3,4,5-trimethoxybenzaldehyde, morpholine, and two different cyanide sources. Molecular characterization was performed by Fourier transform infrared spectroscopy, gas chromatography–mass spectrometry, (1H, 13C – mono and bidimensional) nuclear magnetic resonance; crystallographic characterization was completed by X-ray powder diffraction of polycrystalline samples. The title compounds crystallized in a monoclinic system and unit-cell parameters are reported [a = 13.904(2), b = 5.1696(6), c = 21.628(3) Å, β = 104.31(1)°, unit-cell volume V = 1506.3(3) Å3, Z = 4]. All measured lines were indexed with the P21/a (No. 14) space group.