A function has been proposed to evaluate the electron density model constructed by inverse Fourier transform using the observed structure amplitudes and trial phase set. The strategy of this function is applying an imaginary electron density modification to the model, and then measuring how well the calculated structure amplitudes of the modified model matches the expected structure amplitudes for the modified correct model. Since the correct model is not available in advance, a method has been developed to estimate the structure amplitudes of the modified correct model. With the estimated structure amplitudes of the modified correct model, the evaluation function can be calculated approximately. Limited tests on simulated diffraction data indicate that this evaluation function may be valid at the data resolution better than 2.5 Å.

Different experimental conditions at a versatile high-energy beamline equipped with a two-dimensional detector have been compared for powder diffraction and pair distribution function (PDF) experiments. In particular, sample size and sample to detector distances have been evaluated on a standard sample, to evaluate their effects in both Q and real space. Two illustrative cases are also discussed. The average structure and local distortions in a BaTiO3 powder with 100 nm particle size show that spurious ripples in the PDF are suppressed by increased counting statistics. Effects of small amounts of a crystalline impurity phase on a SiO2.Al2O3.Na2O.CaO glass have been quantified.

Several methods can be used to obtain, from powder diffraction patterns, crystallite size and lattice strain of polycrystalline samples. Some examples are the Scherrer equation, Williamson–Hall plots, Warren/Averbach Fourier decomposition, Whole Powder Pattern Modeling, and Debye function analysis. To apply some of these methods, it is necessary to remove the contribution of the instrument to the widths of the diffraction peaks. Nowadays, one of the main samples used for this purpose is the LaB6 SRM660b commercialized by the National Institute of Standard Technology; the width of the diffraction peak of this sample is caused only by the instrumental apparatus. However, this sample can be expensive for researchers in developing countries. In this work, the authors present a simple route to obtain micron-sized polycrystalline CeO2 that have a full width at half maximum comparable with the SRM660b and therefore it can be used to remove instrumental broadening.

Powder X-ray diffraction has become a routine procedure for the quantification of phases in mixtures. The most common method for this measurement is the Rietveld method, which generally returns the relative weight percentages of the crystalline components within the mixture. However, in many instances, it is also desirable to obtain an estimate of the amorphous content of a sample. There are several methods that may be used for this measurement and their accuracy has been assessed previously with a number of ideal, synthetic mixtures. Many samples, especially in the mineralogy sphere, are far from ideal and contain multiple phases of varying absorption contrast. This creates a microabsorption problem which affects the accuracy of the determination of both the crystalline and amorphous components. This paper assesses commonly used methods of amorphous determination with a series of synthetic samples designed to create a considerable microabsorption problem.

The triplite LiFeSO4F displays both the highest potential ever reported for an Fe-based compound, as well as a comparable specific energy with that of popular LiFePO4. The synthesis is still a challenge because the present approaches are connected with long time, special equipments or organic reagents, etc. In this work, the triplite LiFeSO4F powder was synthesized through an ambient two-step solid-state route. The reaction process and phase purity were analyzed, coupled with structure refinement and electrochemical test.

The crystal structure of methylprednisolone acetate form II, C24H32O6, has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Methylprednisolone acetate crystallizes in space group P212121 (#19) with a = 8.17608(2), b = 9.67944(3), c = 26.35176(6) Å, V = 2085.474(6) Å3, and Z = 4. Both hydroxyl groups act as hydrogen bond donors, resulting in a two-dimensional hydrogen bond network in the ab plane. C–H⋯O hydrogen bonds also contribute to the crystal energy. The powder pattern is included in the Powder Diffraction File™ as entry 00-065-1412.

The crystal structure of MoO2(O2)H2O has been solved by analogy with the WO2(O2)H2O structure and refined with synchrotron powder diffraction data obtained from beamline 08B1-1 at the Canadian Light Source. Rietveld refinement, performed with the software package GSAS, yielded monoclinic lattice parameters of a = 12.0417(4) Å, b = 3.87003(14) Å, c = 7.38390(24) Å, and β = 78.0843(11)° (Z = 4, space group P21/n). The structure is composed of double zigzag molybdate chains running parallel to the b-axis. The Rietveld refined structure was compared with density functional theory (DFT) calculations performed with CRYSTAL14, and show strong agreement with the DFT optimized structure.

The reduction of cis-[CoIII(κ2N,N′-1,10-phenanthroline-5,6-dione)2Cl2]Cl into the neutral compound cis-[CoII(κ2N,N′-1,10-phenanthroline-5,6-dione)2Cl2] was observed during developmental studies of new antimalarial drugs. The crystal structure of cis-[CoII(κ2N,N′-1,10-phenanthroline-5,6-dione)2Cl2] was unveiled by powder X-ray diffraction studies (PXRD). PXRD details, unit cell parameters, and space group for cis-[CoII(κ2N,N′-1,10-phenanthroline-5,6-dione)2Cl2], C24H12Cl2CoN4O4, are reported [a = 41.4951 (13) Å, b = 8.2768 (2) Å, c = 12.4994 (3) Å, unit cell volume V = 4292.9 (2) Å3, Z = 8, and space group Fdd2]. Infrared spectroscopy features are also discussed.

Commercially available trisodium hexachlororhodate (Na3RhCl6) was dehydrated and characterized by laboratory X-ray powder diffraction. The crystal structure is isostructural to the Na3CrCl6 structure type with space group P$\bar 31$c. Unit-cell parameters are a = 6.8116(1) Å, c = 11.9196(2) Å, V = 478.95(2) Å3, and Z = 2.

The Schiff base N1,N2-di(2-hydroxy)benzylidenebenzene-1,2-di-imine was prepared from salicylaldehyde and 1,2-diaminobenzene by reflux in ethanol for 6 h obtaining an orange crystalline solid. The Schiff base solid was separated by filtration and washed with ethanol and ethylic ether, and finally, it was dried in a vacuum system for 2 h. The X-ray powder diffraction pattern for this new compound showed that the crystalline compound belongs to the monoclinic system and space group P21/c (No. 14) with refined unit-cell parameters a = 5.9672 (7) Å, b = 16.561 (1) Å, c = 16.337 (2) Å, β = 91.41° (1). The volume of the unit cell is V = 1614.1 (2) Å3.

Estradiol valerate (brand name: Delestrogen) is used as a hormone replacement therapy for menopause symptoms and for treating advanced prostate cancer. Commercial estradiol 17β valerate crystallizes in the monoclinic space group P21 with a = 7.36787(3), b = 19.84900(6), c = 13.99395(10) Å, β = 90.6845(5)°, V = 2046.398(18) Å3, and Z = 4.