X-ray powder diffraction data are reported for the [(NH4)3Al1−xFex/2Crx/2(C2O4)3]·3H2O solid solution. The crystal system is triclinic with space group P1. Refined unit-cell parameters are given for the compositions x=0.10, 0.50 and 0.80.

Precision X-ray powder-diffraction data of pure solid C70 is reported. C70 prepared by slow evaporation of C70-in-toluene solution adopts an hcp structure (space group P63/mmc) with lattice parameters a=10.5934(10)Å and c=17.262(2)Å.

X-ray powder-diffraction data for Pb2(C2O4)(NO3)2·2H2O were obtained. The crystal system was determined to be monoclinic. The unit-cell parameters were refined to a=10.613(2) Å, b=7.947(2) Å, c=6.189(1) Å, and β=104.48(2)°.

Calculated patterns for the BaR2PdO5 series, in which X is Pd and R=Nd, Sm, Eu, or Gd, have been prepared for materials characterization until experimental patterns can be determined. These compounds are isostructural to the superconductor related “brown phases” BaLa2CuO5 and BaNd2CuO5, which are tetragonal with space group P4/mbm, Z=4. The cell parameters of the Eu and Gd compounds were derived from the La and Nd analogs. The calculated patterns of these four compounds compared well to an experimental pattern of BaNd2CuO5.

The crystal structure of [Pd(NH3)4]C2O4 was determined from X-ray powder data. The crystals are triclinic with unit-cell parameters: a=7.0807(7) Å, b=7.0806(7) Å, c=3.8011(5) Å, α=91.910(1)°, β=98.665(1)°, γ=97.283(1)°, S.G.=P−1, Z=1, V=187.11 Å3. All non-hydrogen atoms were located from the Patterson map. The structure was refined by the Rietveld technique: Rp−b=6.88, Rwp=6.51, RB=2.66. The crystal structure of [Pd(NH3)4]C2O4 is built from two types of elements: [Pd(NH3)4]2+ and C2O2−4. Cations [Pd(NH3)4]2+ form columns along c with distances (Pd–Pd)=3.8011 Å. C2O2−4 anions occupy places in the middle of the unit cell between layers of [Pd(NH3)4]2+. The compound is stable up to 200 °C and then decomposes, giving Pd powder.

Algorithms are presented to correct intensities affected by divergence slit attenuation in the low 2θ region of Bragg–Brentano powder diffractometers with rectangular sample holders. The intensity loss below a limiting angle 2θ1 occurs when the X-ray beam cross section exceeds the sample surface at decreasing angles. For identification purposes, the observed intensities can be scaled up to values comparable with intensities unaffected by divergence slit effects.

A precise X-ray powder diffraction pattern of the orthorhombic form of InVO4, InVO4-III, was obtained using a Huber camera with CuKα1 radiation (λ=1.5406 Å) and Si as internal standard (a= 5.4308 Å). Refinements of indexed reflections led to the following parameters: a=5.7531(3)Å, b=8.5201(4)Å, c=6.5781(3)Å, space group Cmcm, Z =4, Dx=4.733 g/cm3, Dm=4.65 g/cm3. The Smith–Snyder figure-of-merit is F30=201.4 (0.004, 34).

Indexed X-ray diffraction data are reported for 1-adamantanol. The data were indexed on a tetragonal unit cell with a=15.869 Å and c=6.879 Å, P44/nZ=8.

A new compound—Ba3MnSi2O8 in the system BaO–MnO–SiO2 was synthesized and studied by powder X-ray diffraction. The compound is hexagonal, space group—P6/mmm, a=5.67077 Å, c=7.30529 Å, Z=1, Dx=5.353. The obtained powder X-ray diffractometry (XRD) data were interpreted by the Powder Data Interpretation Package.

Powder X-ray diffraction data are reported for La1−xSrxCo0.8Fe0.2O3 (x=0.2, 0.4) and La0.8Ba0.2Co0.8Fe0.2O3. The powders were prepared by thermal decomposition of metal-containing complex solutions. All compositions have rhombohedral unit cells. In hexagonal setting, the cell parameters are a=5.4451(2) Å, c=13.2553(2) Å for La0.6Sr0.4Co0.8Fe0.2O3; a=5.4556(3) Å, c=13.1999(2) Å for La0.8Sr0.2Co0.8Fe0.2O3 and a=5.4795(1) Å, c=13.2983(5) Å for La0.8Ba0.2Co0.8Fe0.2O3. The space group is probably R3c (167) for all three compositions.

The crystal structure of La1−xSrxCoO3−δ (0≤x≤0.6) has been studied, using powder X-Ray diffraction. The crystal structure shows a transition from rhombohedral distorted perovskite for LaCoO3−δ into cubic perovskite for La0.4Sr0.6CoO3−δ. The cubic unit cell parameter is ac=3.8342(1) Å for La0.4Sr0.6CoO3−δ, the space group probably being Pm3m. Using a hexagonal setting, the cell parameters for La0.5Sr0.5CoO3−δ, are a=5.4300(3) Å, c=13.2516(10) Å; a=5.4375(1) Å, c=13.2313(4) Å for La0.6Sr0.4CoO3−δ; a=5.4437(1) Å, c=13.2085(5) Å for La0.7Sr0.3CoO3−δ; a=5.4497(2) Å, c=13.1781(6) Å for La0.8Sr0.2CoO3−δ and a=5.4445(2) Å, c=13.0936(6) Å for LaCoO3−δ with the space group probably being R3c.

A rapid whole-pattern profile-matching procedure for the quantitative assessment of multiphase powder diffraction patterns is described. Using a position-sensitive detector, with fixed beam-sample-detector geometry, we report on the efficacy and speed of this method in the quantitative assessment of four different multiphase samples.

Indexed powder diffraction patterns and related crystallographic data are reported for ErNiSb, which is not represented in the X-ray Powder Diffraction File. The compound ErNiSb is cubic [space group F43m, Z=4, a=6.2693(1) Å]. The R=0.067 indicates that experimental intensities agree well with the calculated patterns.

A model for the crystalline structure of Ba2YCu0.25W0.75O6 solid solution is given. The model proposed a perovskite ordered structure, with a cubic unit cell made from eight perovskite-like units and having a symmetry described by the space group Fm3m. The crystalline structure was refined by the Rietveld technique, giving RF=0.048 for 82 reflections. The solid solution was characterized by the following parameters: Z=4, Mr=613.2, a=8.43630(8) Å, V=600.42(1) Å3, Dx=6.78 g cm−3, μ=209.04 mm−1, and F(000)=1047. The model assumed that copper and tungsten atoms, which were ordered with Y atoms, had the same local environment. Therefore, it was only a first approximation to the crystalline structure.

Hanawaltite, ideally Hg1+6Hg2+O3Cl2, is orthorhombic, Pbma (57), with unit-cell parameters refined from powder data: a=11.790(3), b=13.881(4), c=6.450(2) Å, V=1055.7(6) Å3, a:b:c =0.8494:1:0.4647, Z=4. The strongest six lines of the X-ray powder-diffraction pattern [d in Å (I)(hkl)] are: 5.25 (80)(111), 3.164 (60)(231), 3.053 (100)(041), 2.954 (70)(141), 2.681 (50)(401), and 2.411 (50)(232,341). The mineral is an extremely rare constituent in a small prospect pit near the long-abandoned Clear Creek mercury mine, New Idria district, San Benito County, California. It was found on a single-fracture surface where it is intimately associated with calomel, native mercury, cinnabar, montroydite, and quartz. Individual crystals are subhedral to anhedral, platy to somewhat bladed, and average about 50 μm in longest dimension. The largest known crystal is approximately 0.3×0.3 mm in size and is striated parallel [001]. Hanawaltite is opaque to translucent (on very thin edges), black to very dark brown–black in color, with a black to dark red–brown streak. Other physical properties include: metallic luster; cleavage {001} good; uneven fracture; brittle; nonfluorescent; H<5; calculated density (for the empirical formula) 9.51 g/cm3.

In polished section, hanawaltite is moderately to strongly bireflectant and is pleochroic white (RI) to blue–white (R2). In reflected plane-polarized light, it is white with orange–red internal reflections in very thin grains and at grain margins. The anisotropy is strong with bright metallic blue rotation tints. Measured reflectance values, in air and in oil, are tabulated. Electron-microprobe analysis yielded Hg2O 82.46, HgO 14.27, Cl 3.33, H2O [0.34], sum [100.40], less O=Cl 0.75, total [99.65] wt. %, corresponding to Hg1+6.00Hg2+1.00 [Cl1.43(OH)0.57]Σ2.00O3.00, based on O+Cl=5. After the crystal structure was determined, the original microprobe value for Hg2O, 96.2, was partitioned in a ratio of 6Hg2O:HgO and (OH) was calculated, such that Cl+(OH)=2. The hanawaltite structure consists of undulatory [Hg–Hg]2+ ribbons which roughly parallel (100). The diatomic [Hg–Hg]2+ groups have anion tails which, in turn, serve as cross linkages between dimer ribbons through [Hg2+O2Cl2] planar rhombs. The structure is compared to that of other mercury oxychlorides and each is found to have its own unique structural features. This structural diversity is attributed to the inherent ability of mercury to adopt either metallic or ionic types of bonds. The mineral name honors the late Dr. J. D. (Don) Hanawalt (1903–1987), who was a pioneer in the field of X-ray powder diffraction.

The title materials are stuffed cristobalites possessing moderate to extreme pseudosymmetry. On the bases of their X-ray powder diffraction patterns, the Mg, Zn, and Cd compounds had been previously reported as cubic and, more recently, the Zn phase as orthorhombic. Newly measured X-ray powder diffraction data demonstrate that all (including the hitherto unknown Co analog) have the Pca21 structure of Na2BeSiO4 at room temperature, but with a widely variable degree of cubic pseudosymmetry. Observed X-ray diffraction data are in good agreement with those calculated by the Rietveld method using a constrained model with Pca21 M2+/Si site occupancy and pseudocentrosymmetric Pcab atom locations. For the most nearly cubic phase, the Cd compound, there is too little deviation in the pattern from cubic symmetry to support atom coordinate refinement even with the constrained model. In these derivatives of the stuffed cristobalite structure family, M2+ and Si atoms form an ordered tetrahedral array which avoids M2+–O–M2+ connections. Potassium atoms fill all of the intervening large cavity sites.

Crystal and X-ray powder diffraction data are presented for BaPbO3. The powder pattern was indexed and refined on an orthorhombic cell with a=6.0264(3)Å , b=8.5078(3)Å , c=6.0629(2)Å, Z=4, space group Imma. The phase may actually be monoclinic with space group I2/m, but no distortion from the orthorhombic cell was evident in the powder patterns, suggesting a β angle very close to 90.0°.

Improved powder XRD patterns for the titanium suboxides, TinO2n−1 (4≤n≤9), have been calculated from published single-crystal structures. To provide the best match with experimental data, the entire diffraction traces were simulated, and d-spacings and intensities extracted in the same manner as from experimental traces. The accuracy of the new patterns has been verified by comparison with measured powder patterns, particularly in the case of the n=4 and n=5 compounds where single-phase powders can be prepared relatively easily. Difficulties experienced preparing higher homologues have been related to the thermodynamic properties of this system.