issue contents

Journal logoFOUNDATIONS
ADVANCES
ISSN: 2053-2733

November 2004 issue

Highlighted illustration

Cover illustration: Diffuse scattering about the 002 reflection of an AlAs/GaAs superlattice grown on an oriented GaAs substrate. The in-plane and out-of plane components of the momentum transfer vector are oriented horizontally and vertically, respectively. The observed features are explained on the basis of the distorted-wave Born approximation. See Chernov et al. [Acta Cryst. (2003), A59, 551-559].

research papers


link to html
Eight minimal 3-periodic nets without collisions are identified and their natural tilings and duals are described.

link to html
A detailed investigation of the conditions for the formation of X-ray shift fringes is carried out, aiming to apply these patterns to investigations of crystal imperfections.

link to html
Crystal structural parameters (21 positional parameters and nine isotropic Debye–Waller factors) of the intermediate phase of hexagonal barium titanate (h-BaTiO_3) have been refined by a structure analysis method using convergent-beam electron diffraction (CBED).

link to html
A general theory is developed to describe the phenomenon of step interlacing, i.e. the splitting of unit-cell-height steps into lower steps, on crystal surfaces in relation to crystallographic symmetry. The results are compared with growth step patterns on different kinds of crystals as reported in the literature.

link to html
A review of 4 × 4 matrix notation and of tensor formalism focused on crystallographic applications, including examples from crystallographic computing.

link to html
The use of isotropic displacement parameters for H atoms is shown to have a large impact on the static electron-density model of molecular crystals. A procedure to estimate anisotropic displacement parameters for H atoms in agreement with neutron diffraction parameters is developed and validated.

link to html
Various Laue and Bragg components of diffraction from cylindrical crystals, the dependence of these components on Bragg angle θB and on μρ, and the related diffraction behaviors are analyzed quantitatively.

link to html
The diffuse scattering from a one-dimensional paracrystalline chain of scatterers with various types of correlations between their sizes and relative positions is studied. The encompassed couplings are the simplest ones: size–size, size–separation distance and size–separation distance fluctuation. This paper sheds light on the difficulty of applying simple approximations to a study on the scattering from disordered systems, in particular when correlations between scattering entities are involved.

link to html
All the real crystal rhombododecahedra (625 in total) are enumerated and characterized by facet symbols and symmetry point groups. Nine combinatorially different types are found among the garnets from Mt Makzapakhk, Kola Peninsula.

link to html
A special case of three diffracted X-ray beams is reported.

link to html
Atomic resolution low-angle bright-field (LABF) scanning transmission electron-microscope (STEM) images and high-angle bright-field (HABF) STEM images of [011]-orientated Si have been experimentally obtained together with high-angle annular dark-field (HAADF) STEM images. The contrast formation mechanisms of the LABF STEM and HABF STEM images are examined in comparison with HAADF STEM images. The HABF STEM images independent of defocus and thickness have spatial resolution comparable with HAADF STEM images, and the images are shown to be given as a simple convolution under the non-dispersion approximation of localized Bloch waves.

link to html
A new technique that gives a substantial increase in the wavevector q resolution of triple-axis spectrometers is introduced.

link to html
The charge flipping algorithm is generalized to superspace. It allows for an ab inito solution of modulated structures directly in superspace.

link to html
Zones and sublattices are derived for hexagonal lattices with axial ratios c/a given by \sqrt{{{3}\over{2}}}, \sqrt{3}, \sqrt{2} and 1 (the isometric case) and for the related \sqrt{3} and \sqrt{2} tetragonal lattices.

link to html
A method for construction of molecular crystal global phase diagrams is described. The phase diagrams summarize phase behavior of molecules with a given molecular point-group symmetry. The method is illustrated for the tetrahedral point group Td.

short communications


Acta Cryst. (2004). A60, 637
doi: 10.1107/S0108767304024845
link to html
Space-group scanning tables not explicitly given in Volume E of International Tables for Crystallography are presented.

letters to the editor


addenda and errata


Acta Cryst. (2004). A60, 640
doi: 10.1107/S0108767304024730

book reviews


books received


Acta Cryst. (2004). A60, 642
doi: 10.1107/S0108767304021695

Acta Cryst. (2004). A60, 642
doi: 10.1107/S0108767304021701

Acta Cryst. (2004). A60, 642
doi: 10.1107/S0108767304021713

international union of crystallography


Follow Acta Cryst. A
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds