Abstraet.The crystal structure of the new zeolite mineral gobbinsite, Cao.6Na2.6K2.2Al6Si¡o032 . 12H20, has been determined in the space groupPmn2¡ with a = 10.108(1), b = 9.766(1) and e = 10.171(1) Á. The topology of the framework is the same as that of gismondine and can be describedas a stacking of2-dimensional arrays of double crankshaft chains. The structure was refined by the Rietveld tec...

The line-broadening of a sample of a powder of non-stoichiometric hexagonal ε-iron nitride with the average composition FeN0.433 was analysed by X-ray diffraction. A nearly Gaussian purely strain-like broadening was observed. The broadening is strongly orientation dependent. For each direction of the diffraction vector relative to the crystallographic axes the width of the reflections varies pr...

The crystal structures of triethyl-1,3,5-triazine-2,4,6-tricarboxylate (I), triethyl-1,3,5-benzenetricarboxylate (II) and tris-2-hydroxyethyl isocyanurate (III) have been determined from conventional laboratory X-ray powder diffraction data using the differential evolution structure solution technique. The determination of these structures presented an unexpectedly wide variation in levels of d...

The structural characterization of the new iron-zinc hepta-borate bromide with composition Fe(1.59)Zn(1.41)B(7)O(13)Br, prepared by chemical transport is reported. A rigid-body model with constrained generalized coordinates was defined in order to hold the positions of the B atoms at reasonable inter-atomic distances that typically would reach unacceptable values because of the weak scattering ...

The new crystal structure of 5,6-dibromoacenaphthene has been successfully determined from X-ray powder diffraction data with monoclinic crystals, P21/n, a = 7.88(1) Å, b = 11.64(1) Å, c = 11.62(1) Å, β =107.09(9)°, V = 1019.9(1) Å and Z = 4. Individual reflection intensities were extracted by means of Le Bail’s method. The molecular structure of 1 was solved by direct methods and refined using...

X-ray powder diffractometry/Rietveld refinement was employed to estimate the purity of several chrysotile powders for calibrating standards. α-Corundum powder was mixed into each chrysotile sample as an internal standard. X-ray diffractometry was performed on these mixtures, and the mass fractions of amorphous and impurity phase content were calculated using Rietveld refinement. The chrysotile ...

In this study, we intend to assess the improvements of Gerrit. The central concern is “Does Rietveld evolve into Gerrit as the developers intended?” To answer this question, we first compare qualitative features of two code review tools. We then conducted an interview with a developer of Gerrit and obtained the developer’s original intention of improvements in Gerrit. By analyzing mined data fr...

The average and local structures of the PbTe 1−x PbS x system of thermoelectric materials has been studied using the Rietveld and atomic pair distribution function methods. Samples with 0.25 x are macroscopically phase separated. Phase separation was suppressed in a quenched x=0.5 sample which, nonetheless, exhibited a partial spinodal decomposition. The promising thermoelectric material with x...

In this paper we describe the capabilities for texture measurements of the new neutron time-offlight diffractometer HIPPO at the Los Alamos Neutron Science Center (LANSCE). The orientation distribution function (ODF) is extracted from multiple neutron time-of-flight histograms using the full-pattern analysis first described by Rietveld. Both, the well-established description of the ODF using sp...