A new organic–inorganic hybrid lithium m-phenylenediamine sulfate (LPS), Li2(C6H10N2)(SO4)2, was synthesized under aqueous solution conditions. The X-ray powder diffraction study determined that the title compound crystallized in a monoclinic system at 300 K, with unit-cell parameters a = 7.8689(6) Å, b = 6.6353(5) Å, c = 11.8322(10) Å, β = 109.385(3) °, V = 582.77(8) Å3. Indexing of the diffraction patterns collected from 100 to 600 K reveals that LPS has no structural phase transition within the measured temperature range, and the volume expansion coefficient is approximately 2.79 × 10−5 K−1. The crystal structure was solved based on the single-crystal diffraction data with space group P21/m. Lithium and SO42− are found to form quasi-two-dimensional anti-fluorite [LiSO4] layers stacking along the c-axis, with m-phenylenediamine molecules inserted in the anti-fluorite layers and forming hydrogen bonds to the SO42−. This explains a moderate anisotropic expansion in LPS.

A novel sealed gaseous parallel plate avalanche chamber detector is described which is significantly less prone to discharges and can consequently achieve high gas gains at high counting rates. The detector has demonstrated stable gains greater than 104 at counting rates in excess of 107 counts/mm2 s.

The crystal structure of varenicline hydrogen tartrate Form B (Chantix®) has been refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Varenicline hydrogen tartrate Form B crystallizes in space group P212121 (#19) with a = 7.07616(2), b = 7.78357(2), c = 29.86149(7) Å, V = 1644.706(6) Å3, and Z = 4. The hydrogen bonds were identified and quantified. Hydrogen bonds link the cations and anions in zig-zag chains along the b-axis. The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™ (PDF®).

Pyrolytic graphite is frequently used as a post diffraction monochromator with powder diffractometers of the Bragg-Brentano type. Curved graphite monochromators yield high intensities and suppress efficiently fluorescent radiation except from the element which is the same as the target element of the X-ray tube. They are not, however, able to separate the Kα1 line from the Kα2 component with the X-ray targets normally used in powder diffraction. Crystals with smaller mosaic spread than graphite are needed for selecting a pure Kα1 line. Commercially available crystals which are suitable for this purpose are asymmetrically cut curved quartz and germanium monochromators of the Johansson type. Experiments have been carried out in this laboratory with two quartz monochromators and one germanium monochromator.

Polycrystalline BaTi1−x(Zn1/3Nb2/3)xO3 (x=0.025 and 0.9) compounds were synthesized successfully and studied by XRD and dielectric measurements. The effects of the Ti/(Zn,Nb) ratio on the structure and dielectric properties of the compounds were investigated. XRD results indicated that the crystal structure of the x=0.09 compound is cubic perovskite with space group Pm3m and a=4.0095(4) Å. For the x=0.09 compound, a splitting of the (200) peak was observed near 40.2°, indicating that the crystal structure changed from cubic to tetragonal, with space group P4mm, a=4.026(4) Å, and c=4.0091(4) Å. Rietveld refinement of the crystal structures led to final confidence factors Rp=0.0353 and Rp=0.0349 for x=0.025 and 0.9, respectively. Dielectric measurements showed a relaxor behavior present in BaTi0.1(Zn1/3Nb2/3)0.9.

In the preparation of ceramic SrCe0.95Yb0.05O3−α great care was taken to obtain a homogeneous, carbonate free and dense material of exactly the given composition. The material is an important high-temperature protonic conductor (HTPC). X-ray powder diffraction data are reported. The cell parameters obtained are a=6.007(2) Å, b=12.296(3) Å, c=8.588(2) Å, cell volume 634.4(1) Å3, Z=8. The space group is most probably Pnma (62) and Dx=5.806(2) g/cm3. The bending strength of the sintered dense material is 175±6 MPa.

A new software application has been developed to provide a convenient method for the submission of diffraction data directly to the International Centre for Diffraction Data, for inclusion in the Powder Diffraction File (PDF)™. The application, titled Genie, acts as a portal for the merging of data from separate sources allowing the user to quickly and easily submit their data for the PDF. Using Java Web Start technology Genie can be run using all common computer platforms. Genie is flexible and can be used to read a variety of common file formats. Furthermore, Genie can also be used for submission of New Diffraction Data for publication in the Powder Diffraction Journal.

Structure and optical properties have been successfully determined for a series of niobium- and tantalum-containing layered alkaline-earth silicate compounds, Ba3(Nb6−xTax)Si4O26 (x = 0.6, 1.8, 3.0, 4.2, 5.4). The structure of this solid solution was found to be hexagonal P-62m (No. 189), with Z = 1. With x increases from 0.6 to 5.4, the lattice parameter a increases from 8.98804(8) to 9.00565(9) Å and c decreases from 7.83721(10) to 7.75212(12) Å. As a result, the volume decreases from 548.304(11) to 544.479(14) Å3. The (Nb/Ta)O6 distorted octahedra form continuous chains along the c-axis. These (Nb/Ta)O6 chains are in turn linked with the Si2O7 groups to form distorted pentagonal channels in which Ba ions were found. These Ba2+ ions have full occupancy and a 13-fold coordination environment with neighboring oxygen sites. Another salient feature of the structure is the linear Si–O–Si chains. When x in Ba3(Nb6−xTax)Si4O26 increases, the bond valence sum (BVS) values of the Ba sites increase slightly (2.09–2.20), indicating the size of the cage becoming progressively smaller (over-bonding). While SiO cages are also slightly smaller than ideal (BVS range from 4.16 to 4.19), the (Nb/Ta)O6 octahedral cages are slightly larger than ideal (BVS range from 4.87 to 4.90), giving rise to an under-bonding situation. The bandgaps of the solid solution members were measured between 3.39 and 3.59 eV, and the x = 3.0 member was modeled by density functional theory techniques to be 3.07 eV. The bandgaps of these materials indicate that they are potential candidates for ultraviolet photocatalyst.

The increasing use of microanalysis techniques to analyze particles has demanded more rapid phase identification methods for samples in the 10 μm size range. The XRD analysis of such particles is routinely accomplished using a Rigaku combination instrument combined with particle handling methods. Several case studies show the variety of material analysis problems that can be solved with this technique including identification of multiple mineral phases, corrosion components, and paint samples.

Two adducts (NH2CH2COOH)3⋅H2BeF4(TGFb) and (NH2CH2COOH)3⋅H2SeO4(TGSe) were obtained and characterized by X-ray powder diffraction. The samples were indexed using the TREOR program [Werner, Z. Kristallogr. Kristallogeom. Kristallphys. Kristallchem. 120, 375–387 (1964)] on a monoclinic unit cell. The lattice parameters of adducts TGFb and TGSe were refined by a least-squares method using the Lattice Constant Refinement Program of the Rikagu software. The refined lattice parameters are a=9.1589(9) Å, b=12.6204(13) Å, c=5.6966(8) Å, β=105.451(9)° for TGFb. The Smith and Snyder figure [Smith and Snyder, J. Appl. Crystallogr. 12, 60–65 (1979)] is F30=39.4(0.0141,54). The refined lattice parameters a=9.5063(11) Å, b=12.8281(10) Å, c=5.8682(7) Å, β=110.353(77)° for TGSe. The Smith and Snyder figure is F30=39(0.0106,73). The powder diffraction results are in agreement with those obtained from single crystal structure data.

X-ray powder diffraction data for the compound 2-nitro-l-phenyl-prop-l-ene, C9H9NO2 are reported. The crystals are orthorhombic and the space group is Pbca[61], with a = 7.576(2), b = 19.452(5), c = 11.269(4)Å, Z = 8 Dx = 1.305, Dm = 1.300(2) g/cm3.

The Monte Carlo—Library Least-Squares (MCLLS) approach has now been developed, implemented, and tested for solving the inverse problem of EDXRF sample analysis. It consists of a linear library least-squares code and a comprehensive Monte Carlo code named CEARXRF that is capable of calculating the unknown sample spectrum, all the elemental library spectra in the sample, and the differential operators for each library spectrum with respect to each element. Two codes with graphical user interface have been designed to implement the MCLLS approach and benchmark results are presented for the two stainless steel samples; SS304 and SS316. The results are accurate, the system is easy to use, and all indications are that this approach will be very useful for the EDXRF practitioner.

Detailed procedures for solving small crystal structures ab initio with the maximum-entropy (ME) methods using X-ray powder diffraction data are described by determining the structure of the low-pressure phase of magnesium boron nitride, Mg3BN3(L), which was previously solved by one of the authors and co-workers using the Patterson method and the direct methods. The simple ME method devised by Gull, Livesey, and Sivia failed to correctly phase the structure-factor data, leading to noninterpretable electron-density maps. This method, maximizing the entropy under the constraints of the observed structure factors with subsequent incorporation of strong extrapolates in the basis set, trapped the solution in a local entropy maximum, from which there is no way to move. The multisolution method of phase determination by entropy maximization and likelihood evaluation, developed by Bricogne and Gilmore, successfully located all the Mg, B, and N atoms in one cycle of phase extension. The correct solution had a highest log-likelihood gain, but a minimum entropy, among the multisolutions generated by phase permutation.

A novel porous material of composition Zn3(VO4)2⋅3H2O was prepared hydrothermally. The solid crystallizes in the hexagonal space group P6, with a=6.078 77(8), c=7.1827(2) Å, and V=229.857 Å3.

The syntheses and crystal structures and magnetic properties of novel RIn3−xTx (R = Gd，Pr；T = Fe，Co，Mn；x = 0–0.3) intermetallic compounds in rare earth-In-3d transition metal ternary system have been systematically investigated. It reveals that RIn3−xTx crystallizes in cubic AuCu3 type structure with a space group of Pm$\bar 3$m and Z = 1. The 1a and 3c crystal positions are occupied by R and In atoms, respectively. The 3d transition metals substitute partly for In and prefer to occupy the 3c site. The lattice parameters and unit cell volumes decrease with increasing the content of 3d transition metal in RIn3−xTx intermetallic compounds. The magnetic properties of RIn3−xTx are sensitive to T content. With increasing T content, GdIn3−xTx alloys show the paramagnetic, mixture of ferromagnetic and paramagnetic and ferromagnetic behavior. T doping into RIn3 induces the presence of ferromagnetic phase in GdIn3−xTx, which is totally different from those of the pure binary RIn3.

The crystal structure of strontium hydrogen citrate monohydrate has been solved using laboratory X-ray powder diffraction data, refined using both laboratory and synchrotron data, and optimized using density functional techniques. Strontium hydrogen citrate monohydrate crystallizes in space group C2/c (#15) with a = 25.15601(17), b = 10.90724(6), c = 6.37341(4) Å, β = 91.9846(6)°, V = 1747.704(12) Å3, and Z = 8. The Sr coordination and the hydrogen bonding result in a layered structure. The SrO8 coordination polyhedra share edges to form corrugated layers parallel to the bc-plane. Hydrogen bonds between the carboxylic acid groups and water molecules link the layers. Intermolecular hydroxyl–carboxyl hydrogen bonds also link the layers in a ring pattern with a graph set symbol R2,2(12). After storage for 2 years, partial re-crystallization occurred, to an as-yet unknown compound with a triclinic unit cell.