Journal of Applied Crystallography

Volume 41, Part 3 (June 2008)

	Cover illustration: Two-dimensional grazing-incidence X-ray scattering pattern for a PS-b-PI thin film deposited on a silicon substrate. Courtesy of Sangwoo Jin et al. [J. Appl. Cryst. (2007), 40, 950-958].

• lead articles
• research papers
• short communications
• computer programs
• letters to the editor
• meetings

lead articles

J. Appl. Cryst. (2008). 41, 491-522  [ doi:10.1107/S0021889808007279 ] Structure refinement: some background theory and practical strategies D. Watkin Synopsis: The algorithms underlying small-molecule refinement programs are described in nonmathematical terms, together with practical examples and advice on their use. Online 19 April 2008

research papers

J. Appl. Cryst. (2008). 41, 523-530  [ doi:10.1107/S0021889808005098 ] Early stages of protein crystallization as revealed by emerging optical waveguide technology A. Boudjemline, D. T. Clarke, N. J. Freeman, J. M. Nicholson and G. R. Jones Synopsis: Dual polarization interferometry supports recent hypotheses that the critical nuclei of protein crystals arise from a large stable disordered protein aggregate. It also promises early detection for the onset of protein crystallization in crystallization trials. Online 8 April 2008

J. Appl. Cryst. (2008). 41, 531-536  [ doi:10.1107/S0021889808005463 ] Error estimates on bond-length and angle corrections from TLS analysis J. Haestier, M. Sadki, A. L. Thompson and D. Watkin Synopsis: Errors on anisotropic displacement parameters are propagated to bond-length and angle corrections from TLS analysis via errors on the TLS parameters. Online 8 April 2008

J. Appl. Cryst. (2008). 41, 537-543  [ doi:10.1107/S0021889808005943 ] Modelling the X-ray powder diffraction of nitrogen-expanded austenite using the Debye formula J. Oddershede, T. L. Christiansen and K. Ståhl Synopsis: Simulations using the Debye formula have been performed to explain the X-ray powder diffraction patterns of stress-free and homogeneous samples of nitrogen-expanded austenite, synthesized by low-temperature gaseous nitriding of stainless steel. Online 8 April 2008

J. Appl. Cryst. (2008). 41, 544-547  [ doi:10.1107/S0021889808007309 ] Imaging of interstitial atoms in Ga1-xMnxAs layers by means of X-ray diffuse scattering M. Kopecký, E. Busetto, A. Lausi, Z. Sourek, J. Kub, M. Cukr, V. Novák, K. Olejník and J. P. Wright Synopsis: The atomic positions of Mn impurities in GaMnAs layers were determined by means of X-ray diffuse scattering. Online 8 April 2008

J. Appl. Cryst. (2008). 41, 554-562  [ doi:10.1107/S0021889808007905 ] Finite size effects on the real-space pair distribution function of nanoparticles B. Gilbert Synopsis: Correct incorporation of finite size effects on the pair distribution function of nanoparticles is important for quantifying the structural effects of finite particle size in nanomaterials. Online 7 May 2008

J. Appl. Cryst. (2008). 41, 563-571  [ doi:10.1107/S0021889808006444 ] Modelling on-axis microdiffraction to investigate crystallographic texture within high-performance polymer fibres R. J. Davies, M. Burghammer and C. Riekel Synopsis: This paper describes the modelling of the azimuthal scattering profiles of high-performance fibres in an on-axis microdiffraction geometry. Online 8 April 2008

J. Appl. Cryst. (2008). 41, 572-583  [ doi:10.1107/S0021889808006894 ] Time-resolved diffraction studies into the pressure acid leaching of nickel laterite ores: a comparison of laboratory and synchrotron X-ray experiments N. V. Y. Scarlett, I. C. Madsen and B. I. Whittington Synopsis: Time-resolved diffraction studies into the pressure acid leaching of nickel laterite ores have been conducted using laboratory X-ray and synchrotron radiation sources. The results are compared with respect to reaction mechanism and data analysis techniques. Online 8 April 2008

J. Appl. Cryst. (2008). 41, 584-591  [ doi:10.1107/S0021889808008649 ] A Yb3+-doped NaY(WO4)2 crystal grown by the Czochralski technique J. Fan, H. Zhang, W. Yu, H. Yu, J. Wang and M. Jiang Synopsis: A series of possible growth faces (hkl) were determined from the crystal lattice and symmetry of Yb3+-doped NaY(WO4)2 according to the Bravais-Friedel Donnay-Harker theory, and the relationship among crystal structure, growth habits and crystal morphology is discussed. In addition, the thermal properties of the crystal, including the specific heat, thermal expansion, thermal diffusion and thermal conductivity, are investigated. Online 19 April 2008

J. Appl. Cryst. (2008). 41, 592-599  [ doi:10.1107/S0021889808011527 ] Correcting resolution bias in electron density maps of organic molecules derived by direct methods from powder data A. Altomare, C. Cuocci, C. Giacovazzo, A. Moliterni and R. Rizzi Synopsis: Correcting resolution bias in electron density maps provides additional power to direct methods when applied to powder data. Online 7 May 2008

J. Appl. Cryst. (2008). 41, 600-605  [ doi:10.1107/S0021889808010716 ] Protein crystals can be incommensurately modulated J. J. Lovelace, C. R. Murphy, L. Daniels, K. Narayan, C. E. Schutt, U. Lindberg, C. Svensson and G. E. O. Borgstahl Synopsis: Diffraction images from an incommensurately modulated crystal containing the profilin:actin complex were indexed using software developed for small-molecule modulated and twinned crystals. Online 14 May 2008

J. Appl. Cryst. (2008). 41, 606-614  [ doi:10.1107/S0021889808012491 ] Different models for the polar nanodomain structure of PZN and other relaxor ferroelectrics T. R. Welberry and D. J. Goossens Synopsis: Computer simulations have been carried out to test the recently proposed model for the nanodomain structure of relaxor ferroelectrics such as lead zinc niobate (PZN). The present results confirm that and as well as the previously proposed types of Pb displacement are viable possibilities, but the number of domain boundaries required to produce sufficiently strong diffuse rods of scattering means that individual domains cannot be described as three-dimensional and must still be considered to be relatively thin plates. Online 14 May 2008

J. Appl. Cryst. (2008). 41, 615-627  [ doi:10.1107/S0021889808012223 ] Size-broadening anisotropy in whole powder pattern fitting. Application to zinc oxide and interpretation of the apparent crystallites in terms of physical models N. C. Popa and D. Balzar Synopsis: A new anisotropic size-broadening model, based on a spherical-harmonics representation and convenient for implementation into Rietveld programs, is described. The model is interpreted in terms of physical models by using ellipsoidal and cylindrical crystallites with lognormal size distributions. Online 14 May 2008

J. Appl. Cryst. (2008). 41, 628-633  [ doi:10.1107/S0021889808012648 ] Application of small-angle scattering to study the effects of moisture content on a native soy protein C. S. Kealley, M. M. Elcombe, R. Wuhrer and E. P. Gilbert Synopsis: The effect of moisture content on native soy glycinin is determined using small-angle scattering techniques. Scattering data suggest that the protein expands as the moisture content increases and a hexagonal crystal structure is demonstrated. Scattering data are complemented by electron microscopy, indicating a corresponding expansion of the microstructure with moisture content. Online 14 May 2008

short communications

J. Appl. Cryst. (2008). 41, 634-636  [ doi:10.1107/S0021889808005876 ] Structure of K2TaF7 at 993 K: the combined use of synchrotron powder data and solid-state DFT calculations L. Smrcok, M. Brunelli, M. Boca and M. Kucharík Synopsis: The structure of the title compound was optimized by energy minimization in the solid state at the DFT level of theory using the lattice parameters obtained from high-temperature synchrotron X-ray powder diffraction data. Online 8 April 2008

J. Appl. Cryst. (2008). 41, 637-640  [ doi:10.1107/S0021889808006481 ] Neutron powder diffraction studies of two spin transition FeII complexes under pressure V. Legrand, F. Le Gac, P. Guionneau and J.-F. Létard Synopsis: The pressure dependences of the lattice parameters of two spin transition compounds, Fe(PM-AzA)2(NCS)2 and Fe(PM-BiA)2(NCS)2 [PM is N-2'-pyridylmethylene, AzA is 4-(phenylazo)aniline and BiA is 4-aminobiphenyl], have been derived from neutron powder diffraction measurements at ambient temperature. Online 19 April 2008

computer programs

J. Appl. Cryst. (2008). 41, 641-643  [ doi:10.1107/S0021889808006985 ] CHAINSAW: a program for mutating pdb files used as templates in molecular replacement N. Stein Synopsis: The CHAINSAW program, which mutates template structures for use in molecular replacement, is described. Online 8 April 2008

J. Appl. Cryst. (2008). 41, 644-646  [ doi:10.1107/S0021889808007966 ] SnB version 2.3: triplet sieve phasing for centrosymmetric structures H. Xu, A. B. Smith, N. V. Sahinidis and C. M. Weeks Synopsis: A new version of SnB implements the triplet sieve method for phasing centrosymmetric structures. Online 8 April 2008

J. Appl. Cryst. (2008). 41, 647-652  [ doi:10.1107/S0021889808008625 ] XVis: an educational open-source program for demonstration of reciprocal-space construction and diffraction principles O. Yefanov, V. Kladko, M. Slobodyan and Y. Polischuk Synopsis: A program for visual demonstration of reciprocal-space building for crystals and the principles of X-ray (electron, neutron) diffraction on bulk and two-layered crystals is presented. Online 7 May 2008

J. Appl. Cryst. (2008). 41, 653-658  [ doi:10.1107/S0021889808012016 ] VESTA: a three-dimensional visualization system for electronic and structural analysis K. Momma and F. Izumi Synopsis: A cross-platform program, VESTA, has been developed for three-dimensional visualization of both structural models and volumetric data such as electron and nuclear densities, Patterson functions, and wavefunctions. Online 14 May 2008

letters to the editor

J. Appl. Cryst. (2008). 41, 659  [ doi:10.1107/S0021889808008832 ] Of crystals, structure factors and diffraction images L. Jovine, E. Morgunova and R. Ladenstein Synopsis: It is suggested that it would be useful if raw X-ray diffraction images could be included in data depositions with the Protein Data Bank. Online 8 April 2008

Copyright © International Union of Crystallography
IUCr Webmaster