An experimental X-ray powder diffraction pattern was produced and analyzed for alpha-polymorphic tegafur, also called Ftorafur (an antineoplastic agent). The indexed data matched the powder patterns in the ICDD PDF-4/Organics database calculated from the reported single-crystal X-ray diffraction data in the Cambridge Structural Database. Alpha tegafur has a triclinic crystal system, with reduced cell parameters of a=16.720(6) Å, b=9.021(5) Å, c=5.995(3) Å, α=93.66(4)°, β=93.15(8)°, γ=100.14(4)°. There are four formula units contained in one unit cell. The cell volume and space group were determined to be 886.27 Å3 and P-1, respectively.

X-ray diffraction techniques have been applied to study the crystallization of poly(ethylene-2,6-naphthalate), PEN. Uniaxial and biaxial orientation of amorphous cast PEN films resulted in stress-induced crystallization of the triclinic α-PEN polymorph. Annealing of the amorphous PEN samples in the range of 160–240 °C produced thermally induced crystallization of α-PEN. Slow cooling of amorphous PEN from the melt state generated α-PEN as well as the triclinic β-PEN polymorph.

The synthesis and X-ray powder diffraction data for the organometallic [Rh2(bim)2(cod)2]Cl2∙2H2O species are reported. Its crystal and molecular structures were determined by simulated annealing and full-profile Rietveld refinement methods. [Rh2(bim)2(cod)2]Cl2∙2H2O was found to crystallize in the orthorhombic Cmca space group. The lattice parameters were determined to be a=21.3574(6), b=10.7764(3), c=14.2795(4) Å, V=3286.5(2) Å3, for Z=4. The crystal structure was found to contain dimeric [Rh2(bim)2(cod)2]2+ cations, in which the bim ligands bridge Rh(cod) fragments with an intermetallic separation of ca. 8.90 Å. The crystal structure is completed by chloride ions and hydrogen-bonded water molecules, situated in the small cavities of the large cation substructure. The conformation of the bim ligand, lying on a crystallographic mirror plane, is rigorously Cs.

The crystal structure of sitagliptin dihydrogen phosphate monohydrate (sometimes referred to as sitagliptin phosphate monohydrate) has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Sitagliptin dihydrogen phosphate monohydrate crystallizes in space group P212121 (#19) with a = 6.137 108(12), b = 9.304 018(14), c = 38.307 67(10) Å, V = 2187.359(8) Å3, and Z = 4. The sitagliptin cation folds so that the two planar portions are roughly parallel. The ammonium group of the sitagliptin cation, the phosphate anion, and the water molecule form a network of strong hydrogen bonds. The result is a two-dimensional network, parallel to the ab plane. Halfway between these hydrogen bond planes, there are planes of high fluorine density. The powder pattern is included in the Powder Diffraction File™ as entry 00-064-1500.

Fe–N thin films were deposited on glass substrates by dc magnetron sputtering under various Ar∕N2 discharge conditions. Crystal structures and elemental compositions of the films were characterized by X-ray diffraction and X-ray photoelectron spectroscopy. Magnetic properties of the films were measured using a superconducting quantum interference device magnetometer. Films deposited at different N2∕(Ar+N2) flow ratios were found to have different crystal structures and different nitrogen contents. When the flow ratios were 60%, 50%, and 30%, a nonmagnetic single-phase FeN was formed in the films. At the flow ratio of 10%, two crystal phases of γ′-Fe4N and ε-Fe3N were detected. When the flow ratio reduced to 5%, a mixture of α-Fe, ε-Fe3N, FeN0.056, and α″-Fe16N2 phases was obtained. The value of saturation magnetization for the mixture was found to be larger than that of pure Fe.

The structure of the metal–organic framework (MOF) compound [{Ca(H2O)6}{CaGd(oxydiacetate)3}2]·4H2O was determined by single-crystal X-ray diffraction and refined using conventional single-crystal X-ray diffraction data. In addition, the structure was refined using powder diffraction data collected from two sources, a conventional X-ray diffractometer in Bragg–Brentano geometry and a 12-detector high resolution synchrotron-based diffractometer in transmission geometry. Data from the latter were processed in three different ways to account for crystalline decay or radiation damage. One dataset was obtained by averaging the multiple detector patterns, another dataset was obtained by cutting the non-overlapping portions of each detector to consider only the first few minutes of data collection and a dose-corrected dataset was obtained by fitting the independent peaks in every dataset and extrapolating the intensity and peak position to the initial time of data collection or to zero-absorbed dose. The compared structural models obtained show that special processing of powder diffraction data produced a much accurate model, close to the single-crystal-based model for this particular compound with heavy atoms in high symmetry positions that do not contribute to a significant number of diffraction intensities.

Two new VAX/VMS computer programs are presented for accessing and searching the Powder Diffraction File (PDF) (1989) of the JCPDS-International Centre for Diffraction Data (ICDD). The programs use binary mapped index files which affords rapid searches of the database. Program LOGIC permits entries in the database to be selected by chemistry, peak position or name constraints. The selected entries may be displayed, printed or graphed. The program can display or print entries from the full PDF-2 (1989) database, if on-line. Program SEARCH searches for patterns in the database which match an unknown set of peaks; the program may be optimized for a wide variety of applications including identification of component phases in mixtures. Commands may be entered to the programs in two modes. In the “novice-friendly” mode, users must answer questions to select options. However, experienced users may opt to use a concise one-line command syntax. The modes may be mixed.

Several hitherto unknown hydrates of magnesium selenate have been formed by quenching aqueous solutions of MgSeO4 in liquid nitrogen. MgSeO4·11H2O is apparently isostructural with the mineral meridianiite (MgSO4·11H2O), being triclinic, $P{\rm \bar 1}$, Z = 2, with unit-cell parameters a = 6.779 00(8) Å, b = 6.965 16(9) Å, c = 17.4934(2) Å, α = 87.713(1)°, β = 89.222(1)°, γ = 63.121(1)°, and V = 736.15(1) Å3 at −25 °C. MgSeO4·9H2O represents a new hydration state in the MgSeO4–H2O system; it is monoclinic, space-group P21/c, Z = 4, with unit-cell parameters a = 7.270 24(6) Å, b = 10.510 94(9) Å, c = 17.4030(2) Å, β = 109.447(1)°, and V = 1254.02(1) Å3 at −22 °C. The heavy-atom structure of MgSeO4·9H2O has been determined by direct-space methods from X-ray powder diffraction data and consists of isolated Mg(H2O)62+ octahedra and SeO42− tetrahedra linked by hydrogen bonds. The remaining three water molecules occupy the space between the polyhedral ions, contributing to the H-bonded network, which comprises 4-, 5-, and 6-membered rings. A third phase has been observed to crystallise prior to the 11-hydrate upon warming of liquid-nitrogen-quenched glass, but this transforms rapidly to the meridianiite-structured 11-hydrate and the identity of this phase is unclear.

Powder X-ray diffraction patterns for three forms of MIL-53(Al), a metal organic framework (MOF) compound with breathing characteristics, were investigated using the Rietveld refinement method. These three samples are referred to as the MIL-53(Al)as-syn (the as synthesized sample), orthorhombic, Pnma, a = 17.064(2) Å, b = 6.6069(9) Å, c = 12.1636(13) Å, V = 1371.3(2) Å3, Z = 4), MIL-53(Al)LT-H (low-temperature hydrated phase, monoclinic P21/c, a = 19.4993(8) Å, b = 15.2347(6) Å, c = 6.5687(3) Å, β = 104.219(4) °, V = 1891.55(10) Å3, Z = 8), and MIL-53(Al)HT-D (high-temperature dehydrated phase, Imma, a = 6.6324(5) Å, b = 16.736(2) Å, c = 12.840(2), V = 1425.2(2) Å3, Z = 4). The crystal structures of the “as-syn” sample and the HT-D sample are confirmed to be the commonly adopted ones. However, the structure of the MIL-53(Al)LT-H phase is confirmed to be monoclinic with a space group of P21/c instead of the commonly accepted space group Cc, resulting in a cell volume double in size. The structure has two slightly different types of channel. The pore volumes and pore surface area were estimated to be 0.11766 (8) cm3/g and 1461.3(10) m2/g for MIL-53(Al)HT-D (high-temperature dehydrated phase), and 0.08628 (5) cm3/g and 1401.6 (10) m2/g for MIL-53(Al)as-syn phases, respectively. The powder patterns for the MIL-53(Al)as-syn and MIL-53(Al)HT-D phases are reported in this paper.

An expanded X-ray quantitative phase analysis method is presented. It is an extension of the method without standards. In order to get the method applied more extensively, there is a discussion at the end of this paper of the suitability of samples.

Crystal structures of Li(Ta0.89Ti0.11)O2.945 and (Li0.977Eu0.023)(Ta0.89Ti0.11)O2.968 were investigated by laboratory X-ray powder diffraction. Both title compounds were trigonal with space group R3c and Z = 6. The hexagonal unit-cell dimensions were a = 0.514 82 9(2) nm, c = 1.377 61 2(4) nm, and V = 0.316 21 6(2) nm3 for the former compound and a = 0.517 71 2(2) nm, c = 1.373 50 0(6) nm, and V = 0.318 81 2(3) nm3 for the latter. The initial structural models, being isostructural with LiTaO3, were refined by the Rietveld method. The maximum-entropy method-based pattern fitting (MPF) method was subsequently used to confirm the validity of the structural models, in which conventional structure bias caused by assuming intensity partitioning was minimized. Atomic arrangements of the final structural models were in excellent agreement with the three-dimensional electron-density distributions determined by MPF.

Divalent metal ions are crucial as cofactors for a variety of intracellular enzymatic activities. Mg2+, as an example, mediates binding of deoxyribonucleoside 5′-triphosphates followed by their hydrolysis in the active site of DNA polymerase. It is difficult to study the binding of Mg2+ to an active site because Mg2+ is spectroscopically silent and Mg2+ binds with low affinity to the active site of an enzyme. Therefore, we substituted Mg2+ with Mn2+:Mn2+ that is not only visible spectroscopically but also provides full activity of the DNA polymerase of bacteriophage T7. In order to demonstrate that the majority of Mn2+ is bound to the enzyme, we have applied site-directed titration analysis of T7 DNA polymerase using X-ray near edge spectroscopy. Here we show how X-ray near edge spectroscopy can be used to distinguish between signal originating from Mn2+ that is free in solution and Mn2+ bound to the active site of T7 DNA polymerase. This method can be applied to other enzymes that use divalent metal ions as a cofactor.

Several compositions of the solid solutions (CaxSr1−x)CuO2 and (CaxSr1−x)2CuO3, both of which are found as minor phases in the high-temperature superconductors, were prepared by solid-state reaction. X-ray powder-diffraction patterns for three compositions of (CaxSr1−x)CuO2 and two for (CaxSr1−x)2CuO3 are presented.

Structural variation of LiMn1.5Ni0.5O4 spinel cathode during the Li+ extraction/insertion reaction was studied using operando X-ray diffraction. It was found that the reaction in the voltage range from 3.5 to 4.9 V consisted of two consecutive two-phase reactions, where three spinel phases of LiMn1.5Ni0.5O4, Li0.5Mn1.5Ni0.5O4 and Mn1.5Ni0.5O4 were identified and the lattice volume change in the whole reaction was evaluated as 6%. The reactions were symmetric and reversible under low-current conditions, but some asymmetries were detected during high current operation. Furthermore, a two-phase reaction between cubic and tetragonal phases was observed in the low-voltage reaction at 2.1–3.5 V, where the lattice volume change was approximately 4.9%. The rate-determining step was discussed based on these operando results.

Lead poisoning is a preventable condition caused by exposure to environmental sources such as lead-containing dust or lead-painted consumer products. The history of lead poisoning prevention has been defined to some extent by the quality of the analytical methods available for lead measurements whether in environmental samples or biological tissues and fluids. The quality of blood lead methods has improved so greatly over the last three decades that we now know far more about the adverse health effects from low-level exposures. Recent evidence suggests that effects such as deficit in IQ occur below the current (periodically revised) U.S. CDC threshold of 10 μg/dL, such that no safe threshold appears to exist for children. Improvements in analytical techniques have also had an impact on the environmental measurement quality, yet many environmental thresholds have remained unchanged for decades. In light of our current understanding of the adverse health effects at low levels of exposure, new thresholds for lead in children’s products have been introduced by the U.S. CPSC. The adequacy of current analytical techniques to detect lead accurately at the new, lower thresholds is questionable. XRF offers the advantage of being rapid and nondestructive compared to techniques such as AAS that require extensive sample preparation. However, the accuracy of handheld XRF determinations of lead in painted toys is generally limited. A brief comparative study on the performance of several analytical techniques for the determination of lead in toys is presented at the end of this paper.

Synchrotron powder diffraction data have been obtained and indexed for ferrous gluconate, a common supplement used for the treatment and prevention of iron-deficiency anemia. Ferrous gluconate (Fe(C6H11O7)2 · x H2O, Z = 4) crystallizes in a monoclinic cell (space group I2, #5) with lattice parameters a = 19.953 16(9) Å, b = 5.513 92(3) Å, c = 18.470 58(9) Å, and β = 111.3826(3)°. The pattern shows no evidence of impurity reflections.

X-ray powder diffraction data collected in transmission and high-throughput geometries were used to analyze form I of atorvastatin. The X-ray wavelength of the synchrotron radiation used in this study was determined to be λ=1.3771 Å. Form I of atorvastatin was found to be triclinic with space group P1 and unit cell parameters a=5.4568(2) Å, b=9.8887(4) Å, c=30.3091(9) Å, α=76.801(3)°, β=99.177(5)°, γ=105.318(5)°, V=1527.1(1) Å3, Z=1, and M=1209.41 g mol−1 Alternatively, another unit cell dimension can be used to describe the same P1 crystal with a=5.4564(2) Å, b=9.8883(4) Å, c=29.6555(8) Å, α=95.745(3)°, β=94.297(5)°, γ=105.327(5)°, and V=1526.8(1) Å3.

An electron probe X-ray microanalysis (EPMA) technique using an energy-dispersive X-ray detector with an ultrathin window, designated low-Z particle EPM, has been developed. The low-Z particle EPMA allows the quantitative determination of concentrations of low-Z elements, such as C, N, and O, as well as higher-Z elements that can be analyzed by conventional energy-dispersive EPMA. The quantitative determination of low-Z elements (using full Monte Carlo simulations, from the electron impact to the X-ray detection) in individual environmental particles has improved the applicability of single-particle analysis, especially in atmospheric environmental aerosol research; many environmentally important atmospheric particles, e.g. sulfates, nitrates, ammonium, and carbonaceous particles, contain low-Z elements. The low-Z particle EPMA was applied to characterize loess soil particle samples of which the chemical compositions are well defined by the use of various bulk analytical methods. Chemical compositions of the loess samples obtained from the low-Z particle EPMA turn out to be close to those from bulk analyses. In addition, it is demonstrated that the technique can also be used to assess the heterogeneity of individual particles.

Silver halide based photographic imaging elements have been utilized as detectors for X-rays for over 100 years. These elements comprised of gelatin dispersed silver halide coated on one or both sides of a support, have been utilized in diffraction experiments since the discovery of X-ray diffraction by Laue and co-workers. X-ray film has high spatial resolution and can be adapted to flat or curved two-dimensional detection geometries. This paper describes the use of X-ray film as a two-dimensional detector for X-ray diffraction analysis, and discusses X-ray film composition, exposure, and processing, along with considerations for analyzing X-ray diffraction data collected using X-ray film.

Powder X-ray diffraction (XRD) data were collected for a new phase of SrGd2O4. Analysis using the Rietveld method was carried out and it was found that the sample crystallizes in the orthorhombic symmetry with CaFe2O4 related structure. The lattice parameters are found to be a=12.0521(2) Å, b=10.1327(2) Å, c=3.4757(4) Å and Z=4. For X-ray data RF=4.9%, RB=7.6%, RP=8.1% and χ2=1.51. The structure can be described as an assembly of bioctahedron [Gd2O10] which are linked together by O2− anions and of dodecahedron of SrO8.