issue contents

ISSN: 2053-2733

January 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

Acta Cryst. (2004). A60, 1-6
doi: 10.1107/S010876730302186X

Acta Cryst. (2004). A60, 7-18
doi: 10.1107/S0108767303022037
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An expression for the topological density of n-dimensional nets is derived from geometrical characteristics associated with their quotient graph.

Acta Cryst. (2004). A60, 19-32
doi: 10.1107/S0108767303022062
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The computational complexity of the structure-factor calculation through an intermediate density generation and its Fourier transform have been studied for the subatomic resolution range. Parameters of the method are suggested that minimize the time of the calculations.

Acta Cryst. (2004). A60, 33-39
doi: 10.1107/S0108767303022633
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The characteristics of ultra-high-angle double-crystal X-ray diffractometry at Bragg angle 89.5° is described together with an application for determining the linear thermal-expansion coefficient of silicon.

Acta Cryst. (2004). A60, 40-50
doi: 10.1107/S0108767303022815
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The paper presents a formalism, based on Takagi's equations and Fourier optics, applicable to the dynamics of X-rays in crystals. The analogy between the dynamics of X-rays and that of two-level quantum systems is exploited to describe X-ray propagation in crystals from a new point of view.

Acta Cryst. (2004). A60, 51-57
doi: 10.1107/S0108767303022803
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Paramagnetic antiferromagnetic CoF2 has been studied by various diffraction techniques. Detailed information on the structural, electronic and magnetic characteristics is presented.

Acta Cryst. (2004). A60, 58-63
doi: 10.1107/S0108767303024504
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Dispersion corrections to the atomic scattering factors for the copper K edge have been measured by a new technique, Fresnel diffraction. The results are comparable to those measured by other techniques.

Acta Cryst. (2004). A60, 64-74
doi: 10.1107/S0108767303025017
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The iterative Born approximation is derived for analysis of the dependence of three-wave dynamical X-ray diffraction profiles on the polarization state of a linearly polarized incident wave. General conditions of the phase sensitivity, the asymmetries of diffraction profiles, as well as the prediction of new diffraction features are obtained from this approximation and compared with direct dynamical calculations.

Acta Cryst. (2004). A60, 75-81
doi: 10.1107/S0108767303025042
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The metal-rich structures of Ti11Se4 and Ti45Se16, which were determined by electron crystallography, have been validated by means of total energy calculations within the non-local density functional theory (program CASTEP). The calculations proved the correctness of the structures and yielded slightly improved lattice parameters and atomic coordinates for both compounds.

Acta Cryst. (2004). A60, 82-88
doi: 10.1107/S0108767303025303
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The capability of the ab initio structure determination method using X-ray fluorescence holography is proven and it is shown that it does not heavily depend on the holography pattern noise.

Acta Cryst. (2004). A60, 89-95
doi: 10.1107/S0108767303025625
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The symmetry of twins is revised in terms of the lattice point and translational symmetry and the new category of reticular polyholohedry is introduced. Examples from the literature are critically revisited.

international union of crystallography

Acta Cryst. (2004). A60, 96
doi: 10.1107/S0108767303028964

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