scholarly journals AUSPEX: a graphical tool for X-ray diffraction data analysis

2017 ◽  
Vol 73 (9) ◽  
pp. 729-737 ◽  
Author(s):  
Andrea Thorn ◽  
James Parkhurst ◽  
Paul Emsley ◽  
Robert A. Nicholls ◽  
Melanie Vollmar ◽  
...  

In this paper,AUSPEX, a new software tool for experimental X-ray data analysis, is presented. Exploring the behaviour of diffraction intensities and the associated estimated uncertainties facilitates the discovery of underlying problems and can help users to improve their data acquisition and processing in order to obtain better structural models. The program enables users to inspect the distribution of observed intensities (or amplitudes) against resolution as well as the associated estimated uncertainties (sigmas). It is demonstrated howAUSPEXcan be used to visually and automatically detect ice-ring artefacts in integrated X-ray diffraction data. Such artefacts can hamper structure determination, but may be difficult to identify from the raw diffraction images produced by modern pixel detectors. The analysis suggests that a significant portion of the data sets deposited in the PDB contain ice-ring artefacts. Furthermore, it is demonstrated how other problems in experimental X-ray data caused, for example, by scaling and data-conversion procedures can be detected byAUSPEX.

2009 ◽  
Vol 24 (2) ◽  
pp. 171-171
Author(s):  
A. Ulyanenkov ◽  
A. Benediktovitch ◽  
I. Feranchuk ◽  
B. He ◽  
H. Ress

2012 ◽  
Vol 46 (1) ◽  
pp. 108-119 ◽  
Author(s):  
Simon W. M. Tanley ◽  
Antoine M. M. Schreurs ◽  
John R. Helliwell ◽  
Loes M. J. Kroon-Batenburg

The International Union of Crystallography has for many years been advocating archiving of raw data to accompany structural papers. Recently, it initiated the formation of the Diffraction Data Deposition Working Group with the aim of developing standards for the representation of these data. A means of studying this issue is to submit exemplar publications with associated raw data and metadata. A recent study on the effects of dimethyl sulfoxide on the binding of cisplatin and carboplatin to histidine in 11 different lysozyme crystals from two diffractometers led to an investigation of the possible effects of the equipment and X-ray diffraction data processing software on the calculated occupancies andBfactors of the bound Pt compounds. 35.3 Gb of data were transferred from Manchester to Utrecht to be processed withEVAL. A systematic comparison shows that the largest differences in the occupancies andBfactors of the bound Pt compounds are due to the software, but the equipment also has a noticeable effect. A detailed description of and discussion on the availability of metadata is given. By making these raw diffraction data sets availableviaa local depository, it is possible for the diffraction community to make their own evaluation as they may wish.


2020 ◽  
Vol 851 ◽  
pp. 9-15
Author(s):  
Ahmad Taufiq ◽  
M.Sofiyudin Nuroni ◽  
Nurul Hidayat ◽  
ST.Ulfawanti Intan Subadra ◽  
Sunaryono ◽  
...  

In this work, Fe3O4 nanoparticles (NPs) were synthesized using coprecipitation method and TiO2 NPs were synthesized using sonication method. Fe3O4/polyaniline and TiO2/polyaniline nanocomposites (NCs) were synthesized using polymerization methods. The samples were characterized by X-ray diffractometer, Fourier-transform infrared spectroscopy, and ultraviolet-visible spectroscopy. The results of X-ray diffraction data analysis presented that polyaniline decreased the crystallinity of Fe3O4 and TiO2 NPs. However, the crystal structure of Fe3O4 and TiO2 NPs did not change, which successively formed the cubic spinel and the tetragonal anatase phases. Furthermore, the functional groups of Ti-O-Ti and Fe-O were detected in the wavenumber ranges of 620-580 cm-1 and 410-520 cm-1, respectively. The presence of polyaniline was also detected by the emergence of a functional group of polyaniline which also showed that there was an interaction of Fe3O4 and TiO2 NPs with polyaniline. Meanwhile, the results of UV-Vis data analysis showed that the addition of polyaniline decreased the bandgap energy of Fe3O4 and TiO2 NPs significantly from 2.186 to 2.174 eV and from 3.374 to 3.320 eV, respectively.


1991 ◽  
Vol 35 (A) ◽  
pp. 333-340 ◽  
Author(s):  
W.N. Schreiner ◽  
R. Jenkins ◽  
P.F. Dismore

During the course of the past ten years the International Centre for Diffraction Data has sponsored a number of “Round Robin” tests to evaluate the quality of experimental X-ray diffraction data [1-5]. The latest of this series, called the Instrument Parameter Round Robin, was designed to evaluate, among other things, relative angularly-dependent sensitivity differences between diffractometers. Previous experiments have indicated that even perfectly aligned diffractometers of the same generic type, do not necessarily give the same set of relative intensities. One objective of the round robin was to quantify the magnitude of the experimental differences between data sets, and to demonstrate a means for external calibration of diffractometers, so that digitized diffraction intensity data obtained from different instruments could be directly compared.


2004 ◽  
Vol 59 (3) ◽  
pp. 281-285 ◽  
Author(s):  
Matthias Weil

Colourless single crystals of the compounds CdXO4 · 2 HgO (X = S, Se) were obtained under hydrothermal conditions (250 °C, 5 d), starting from stoichiometric amounts of HgO, CdSO4 ·7H2O and CdSeO4 ·2H2O, respectively. The crystal structures were determined from X-ray diffraction data sets. The CdXO4 · 2HgO compounds crystallise isotypically with two formula units in space group P1̅ (# 2) [CdSO4 · 2HgO (CdSeO4 · 2HgO): a = 6.793(2) (6.9097(5)) Å , b = 7.205(2) (7.1786(6)) Å , c=7.359(2) (7.4556(6)) Å ,α =73.224(6) (74.586(2))°, β =66.505(6) (68.229(1))°, γ =63.054(5) (63.886(1))°, 1670 (1786) structure factors, 92 parameters, R[F2 > 2σ(F2)] = 0.0379 (0.0244)] and are made up from zig-zag [O-Hg-O]∞ chains with very short bonds of d̅(Hg-O) 2.025 Å , distorted [CdO6] octahedra (d̅(Cd-O)= 2.297 Å ), and XO4 tetrahedra (d̅(S-O)= 1.458 Å , d̅(Se-O)= 1.633 Å ) as the main building blocks. The CdXO4 ·2HgO compounds reveal no structural relationship with the corresponding HgXO4 ·2HgO phases


2018 ◽  
Vol 51 (4) ◽  
pp. 1094-1101 ◽  
Author(s):  
Yunchen Wang ◽  
Taimin Yang ◽  
Hongyi Xu ◽  
Xiaodong Zou ◽  
Wei Wan

The continuous rotation electron diffraction (cRED) method has the capability of providing fast three-dimensional electron diffraction data collection on existing and future transmission electron microscopes; unknown structures could be potentially solved and refined using cRED data collected from nano- and submicrometre-sized crystals. However, structure refinements of cRED data using SHELXL often lead to relatively high R1 values when compared with those refined against single-crystal X-ray diffraction data. It is therefore necessary to analyse the quality of the structural models refined against cRED data. In this work, multiple cRED data sets collected from different crystals of an oxofluoride (FeSeO3F) and a zeolite (ZSM-5) with known structures are used to assess the data consistency and quality and, more importantly, the accuracy of the structural models refined against these data sets. An evaluation of the precision and consistency of the cRED data by examination of the statistics obtained from the data processing software DIALS is presented. It is shown that, despite the high R1 values caused by dynamical scattering and other factors, the refined atomic positions obtained from the cRED data collected for different crystals are consistent with those of the reference models refined against single-crystal X-ray diffraction data. The results serve as a reference for the quality of the cRED data and the achievable accuracy of the structural parameters.


2006 ◽  
Vol 39 (2) ◽  
pp. 267-272 ◽  
Author(s):  
R. J. Davies

Modern synchrotron radiation facility beamlines offer high-brilliance beams and sensitive area detectors. Consequently, experiments such as scanning X-ray microdiffraction can generate large data sets within relatively short time periods. In these specialist fields there are currently very few automated data-treatment solutions to tackle the large data sets produced. Where there is existing software, it is either insufficiently specialized or cannot be operated in a batch-wise processing mode. As a result, a large gap exists between the rate at which X-ray diffraction data can be generated and the rate at which they can be realistically analysed. This article describes a new software application to perform batch-wise data reduction. It is designed to operate in combination with the commonly usedFit2Dprogram. Through the use of intuitive file selection, numerous processing lists and a generic operation sequence, it is capable of the batch-wise reduction of up to 60 000 diffraction patterns during each treatment session. It can perform automated intensity corrections to large data series, perform advanced background-subtraction operations and automatically organizes results. Integration limits can be set graphically on-screen, uniquely derived from existing peak positions or globally calculated from user-supplied values. The software represents a working solution to a hitherto unsolved problem.


2012 ◽  
Vol 20 (4) ◽  
pp. 4149 ◽  
Author(s):  
Stephan Kassemeyer ◽  
Jan Steinbrener ◽  
Lukas Lomb ◽  
Elisabeth Hartmann ◽  
Andrew Aquila ◽  
...  

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