issue contents

Journal logoJOURNAL OF
ISSN: 1600-5767

February 2009 issue

Highlighted illustration

Cover illustration: Three-dimensional reconstructed crystal (purple), loop (yellow) and solvent (transparent pink) for a native DNA sample. Courtesy of Brockhauser, Di Michiel, McGeehan, McCarthy & Ravelli [J. Appl. Cryst. (2008), 41, 1057-1066].

research papers

J. Appl. Cryst. (2009). 42, 1-9
doi: 10.1107/S0021889808031919
link to html
An approach is proposed providing the means for determining stacking fault properties by analysis of the relative positions of selected pairs of X-ray diffraction peaks.

J. Appl. Cryst. (2009). 42, 10-14
doi: 10.1107/S0021889808034900
link to html
Small-angle X-ray scattering was used to study modifications in the correlation function in tetraethoxysilane-derived poly(vinyl alcohol)/silica hybrids. An additional scattering at low q was found to overlap the fundamental mass-fractal scattering from the basic silica. The fraction of both contributions to the total correlation function was estimated; this is the first time that such a study has been carried out for mass-fractal structures.

J. Appl. Cryst. (2009). 42, 15-21
doi: 10.1107/S0021889808034730
link to html
The high-pressure behavior of nanocrystalline mackinawite (FeS) has been studied by X-ray total scattering experiments and pair distribution function analysis. A pressure-induced structural phase transition has been observed at about 3 GP and from the tetragonal mackinawite structure to orthorhombic FeS-II.

J. Appl. Cryst. (2009). 42, 22-29
doi: 10.1107/S0021889808039435
link to html
The matrix method for diffuse scattering was effectively used to simulate powder X-ray diffraction patterns of misfit mixed-layer compounds in a restacked binary nanosheet system.

J. Appl. Cryst. (2009). 42, 30-35
doi: 10.1107/S0021889808039538

J. Appl. Cryst. (2009). 42, 36-42
doi: 10.1107/S0021889808039125
link to html
It is shown theoretically that single-crystal diamond would be the ultimate neutron monochromator material if it were available as large mosaic crystals. Present chemical vapour deposition growth techniques are capable of preparing single crystals with a suitable mosaic spread and should be further developed with the aim of producing neutron monochromators.

J. Appl. Cryst. (2009). 42, 43-47
doi: 10.1107/S002188980803570X
link to html
The problems associated with cooling powder samples below 1 K are discussed. Two strategies for mounting neutron powder diffraction samples are described and evaluated.

J. Appl. Cryst. (2009). 42, 48-57
doi: 10.1107/S0021889808036716
link to html
An investigation of the usefulness of higher-order least-squares fits in the post-processing of intensity measurements is presented.

J. Appl. Cryst. (2009). 42, 58-62
doi: 10.1107/S0021889808036182
link to html
Atomic coordinate analysis allows the property of ferroelectricity, previously unsuspected in a material, to be recognized if its crystal structure is known. An earlier such prediction that NaSb3F10 is ferroelectric is unambiguously confirmed.

J. Appl. Cryst. (2009). 42, 63-68
doi: 10.1107/S0021889808042039
link to html
The title 1,1′-disubstituted ferrocene derivative exhibits a nematic phase only, and the rod-like shape of the molecule favors liquid crystalline behavior. C—H⋯π, π–π and T-stacking interactions play a major role in stabilizing the molecular packing arrangement and the mesomorphism.

J. Appl. Cryst. (2009). 42, 69-84
doi: 10.1107/S0021889808039162

J. Appl. Cryst. (2009). 42, 85-92
doi: 10.1107/S0021889808036406
link to html
A simple model-independent method is proposed to retrieve strain profiles in thin films using X-ray diffraction. The dynamical diffraction from the substrate as well as the film thickness fluctuations are explicitly taken into account.

J. Appl. Cryst. (2009). 42, 93-100
doi: 10.1107/S0021889808034912
link to html
The effect of pressure on both the structure and the electrical conductivity of the superionic Ag7GeSe5I phase has been studied at room temperature (i) by powder X-ray diffraction from 0.1 MPa to 10 GPa, (ii) by single crystal X-ray diffraction from 0.1 MPa to 2 GPa and (iii) by impedance spectroscopy from 0.1 MPa to 1.5 GPa. The decrease in conductivity of about one order of magnitude, when the pressure increases up to 1.5 GPa, can be explained by the compression of the cell.

J. Appl. Cryst. (2009). 42, 101-108
doi: 10.1107/S0021889808038521
link to html
Conventions are proposed to encode information about the diffraction geometry and polarization properties of the incident X-ray beam in an unambiguous and economical way. The use of these definitions is beneficial in the analysis of polarization-dependent phenomena in X-ray diffraction.

J. Appl. Cryst. (2009). 42, 109-115
doi: 10.1107/S0021889808041277
link to html

The techniques of synchrotron radiation micro-X-ray fluorescence, neutron diffraction and scanning electron microscopy have been applied to the study of different whewellite kidney stones.

J. Appl. Cryst. (2009). 42, 116-124
doi: 10.1107/S0021889808042349
link to html
A template-matching-based indexing scheme for Laue diffraction patterns is implemented, and a method is proposed for misorientation determination within a diffracting volume from smeared/split Laue patterns. The methodologies developed are illustrated using micro-Laue patterns obtained from a fatigue crack-wake.

cryocrystallography papers

J. Appl. Cryst. (2009). 42, 125-128
doi: 10.1107/S0021889808040958
link to html
A small, inexpensive and automatically operated device for the flash annealing of crystals of macromolecules is presented. Operation of the device is completely integrated within the ESRF beamline control graphical user interface for macromolecular crystallography experiments, mxCuBE, and the device can thus be controlled either from the beamline control cabin or by users accessing the beamline remotely.

short communications

J. Appl. Cryst. (2009). 42, 129-133
doi: 10.1107/S0021889808035772
link to html
This paper presents a hands-free protein crystallography system in which all aspects of crystallographic experiments from crystallization to diffraction data collection are performed within a modified X-ray glass capillary.

J. Appl. Cryst. (2009). 42, 134-136
doi: 10.1107/S0021889808041149
link to html
An approach is described where structure solution may be attempted from powders with preferential orientation. Based on spherical harmonics, it does not assume any orientation direction but is stable during simulated annealing. The approach relies on a macro keyword already present in TOPAS, but could be implemented in other simulated annealing codes.

computer programs

J. Appl. Cryst. (2009). 42, 137-139
doi: 10.1107/S0021889808037229
link to html
ACDP is a Java application for processing protein circular dichroism spectra. Three different algorithms for secondary structure deconvolution have been implemented, and spectra can be analysed without the need for data reformatting.

laboratory notes

J. Appl. Cryst. (2009). 42, 140-142
doi: 10.1107/S0021889808035607
link to html
Additional hard- and software allows computer-controlled temperature-dependent X-ray studies and temperature calibration using a Stoe IPDS II with the Heatstream attachment. The presented software is open source and therefore can easily be adapted to other diffractometer platforms with similar gas flow heaters.


J. Appl. Cryst. (2009). 42, 143
doi: 10.1107/S0021889808037412

international union of crystallography

J. Appl. Cryst. (2009). 42, 144-148
doi: 10.1107/S0021889808035383

Follow J. Appl. Cryst.
Sign up for e-alerts
Follow J. Appl. Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds