issue contents
November 1998 issue
research papers
The probability distribution of structure factors with non-integral indices is derived in P1.
Algorithms capable of performing accurate charge-density studies have been implemented within the existing computer program BUSTER, as part of a comprehensive programme for doing crystallography within a Bayesian theory of crystal structure determination. Model studies on noise-free synthetic data sets for α-glycine, silicon and beryllium show that all-electron calculations give rise to artefacts when a uniform prior prejudice is used, while valence-only calculations using valence monopole priors are essentially free from artefacts.
The first detailed X-ray structure analysis of a decagonal quasicrystal with a noncentrosymmetric space group is presented.
The theoretical treatment is given of one-phonon thermal diffuse scattering (TDS) in angular-dispersive neutron diffraction. Just as for time-of-flight neutron diffraction, forbidden TDS regions exist for slower-than-sound neutrons.
An average unit cell for the Fibonacci chain has been constructed in physical space. An analytical expression for the diffraction peak intensities has been derived.
The charge density, structure factors and Compton profiles of SiC-3C have been calculated at the Hartree–Fock and density functional theory levels. The properties of SiC-3C compare very well with those of semiconductors having the same structure as silicon, diamond and cubic boron nitride.
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A compact and intuitive nomenclature is recommended for naming each phase formed by a given material in a sequence of phase transitions as a function of temperature and/or pressure. The most commonly used label for each phase in a sequence, such as α, β, ⋯, I, II, ⋯ etc., is included in the new nomenclature.
short communications
The recursion equations describing X-ray dynamical diffraction in distorted crystals with a three-dimensional deformation field of arbitrary form have been derived. The analytical solution of these equations has been obtained within the kinematical approximation.
book reviews
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books received
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international union of crystallography
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