issue contents
January 2009 issue
research papers
The mystery of observing films that are much thinner than the resolution limit of a reflectivity measurement is explained within the bounds of the kinematic approximation. Although never encountered in crystal structure determination (hence it is not widely known and even seems counter-intuitive to crystallographers), the phenomenon is in no way limited to reflectometry, which could not be described without invoking dynamic scattering theory.
The Debye–Waller factors of group IV, III–V, and II–VI semiconductors are calculated from ab initio force constants and fitted in the temperature range from 0.1 to 1000 K.
Tables of the abelianizations of all the n-dimensional space groups for n = 1, 2, 3 are provided. The exponent of the torsion subgroup of the abelianization of an arbitrary n-dimensional space group is shown to divide the order of its point group.
Multiple-scattering artifacts in soft X-ray diffraction can be completely removed using diffraction patterns recorded at two wavelengths.
In addition to the diverse parameter-retrieval algorithms commonly used for multilayer structure determination, a dynamic Newton–gradient-direction-type algorithm is proposed. It works well and provides the absolute minimum of the error functional even when the initial values of the search parameters are rather far from the true ones.
short communications
The analytical solution of the tilt-angle determination problem in fiber diffraction is presented.
A new method for the deconvolution of the interatomic vector set is presented.
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