Foundations of Crystallography

 

Acta Cryst. (2003). A59, 109-116  [ doi:10.1107/S0108767302022274 ]

X-ray fluorescence holography: a novel treatment for crystal structure determination

F. N. Chukhovskii and A. M. Poliakov

Synopsis: In contrast to conventional X-ray diffraction methods, which do not always work unambiguously, an ab initio technique using X-ray fluorescence data generally provides a unique phase-retrieval solution for crystal structure determination.

Online 26 February 2003

 

Acta Cryst. (2003). A59, 117-126  [ doi:10.1107/S0108767302022559 ]

Structure of Ti₂P solved by three-dimensional electron diffraction data collected with the precession technique and high-resolution electron microscopy

M. Gemmi, X. D. Zou, S. Hovmöller, A. Migliori, M. Vennström and Y. Andersson

Synopsis: The crystal structure of Ti₂P has been solved using direct methods applied to electron diffraction data collected in a selected-area model and using the precession technique. A model of the ordering of the P vacancies in the structure has been obtained from high-resolution images.

Online 26 February 2003

 

Acta Cryst. (2003). A59, 127-131  [ doi:10.1107/S0108767302023127 ]

On the choice of d-orbital coordinate system in charge-density studies of low-symmetry transition-metal complexes

J. R. Sabino and P. Coppens

Synopsis: The description of the d-electron orbital populations of transition-metal atoms requires the assignment of an axis of quantization, which is unambiguous in symmetric environments, but not clear-cut in the now commonly encountered case of a low-symmetry coordination environment. Appropriate criteria are discussed.

Online 26 February 2003

 

Acta Cryst. (2003). A59, 132-137  [ doi:10.1107/S0108767302023139 ]

A one-dimensional model for small-angle X-ray scattering from crystalline block copolymers

D. Villers

Synopsis: This paper develops a one-dimensional mathematical model to model four phase systems that can occur with block copolymers. Applications are presented.

Online 26 February 2003

 

Acta Cryst. (2003). A59, 138-142  [ doi:10.1107/S0108767303000473 ]

A holographic approach to point defect structure determination in inorganic crystals: Er-doped Sc₂O₃

K. Anduleit and G. Materlik

Synopsis: A holography-related approach is used to determine the structure of point defects model-free. Applied to Er-doped Sc₂O₃, an additional position is revealed.

Online 26 February 2003

 

Acta Cryst. (2003). A59, 143-152  [ doi:10.1107/S0108767302022511 ]

Experimental lensless soft-X-ray imaging using iterative algorithms: phasing diffuse scattering

H. He, S. Marchesini, M. Howells, U. Weierstall, G. Hembree and J. C. H. Spence

Synopsis: Images of 50  nm gold balls are reconstructed from their soft-X-ray diffraction patterns by diffractive imaging.

Online 26 February 2003

 

Acta Cryst. (2003). A59, 153-162  [ doi:10.1107/S0108767302022316 ]

Theory of diffraction from D0₁₉ ordered c.p.h. structures containing complex stacking faults on basal planes

P. Ghosal and S. Lele

Synopsis: Diffraction theory from D0₁₉ ordered c.p.h. structures containing complex stacking faults on basal planes are studied. Integrated intensities and widths of the reflections are affected.

Online 26 February 2003

 

Acta Cryst. (2003). A59, 163-167  [ doi:10.1107/S0108767303000485 ]

A universal computation method for two-beam dynamical X-ray diffraction

X. Huang and M. Dudley

Synopsis: A general-purpose method that includes nearly all possible two-beam diffraction mechanisms is presented for calculating diffracted and specularly reflected X-ray intensities from single crystals.

Online 26 February 2003

 

Acta Cryst. (2003). A59, 168-171  [ doi:10.1107/S0108767303002186 ]

Structures of a hollow filamentary conical helix

F.-F. Xu and Y. Bando

Synopsis: Complete structural models have been established for a hollow filamentary conical helix and examined taking into account the wrapping mode, coincidence site lattice, disclination angle and packing pattern. The size of the coincidence site lattice is found to dominate the disclination configuration.

Online 26 February 2003

 

Acta Cryst. (2003). A59, 172-182  [ doi:10.1107/S0108767303002320 ]

The crystallographic fast Fourier transform. II. One-step symmetry reduction

M. Rowicka, A. Kudlicki and Z. Otwinowski

Synopsis: An algorithm for efficient evaluation of the crystallographic FFT for 67 crystallographic space groups is presented. The symmetry is reduced in such a way that it is enough to calculate P1 FFT in the asymmetric unit only and then, in a computationally simpler step, recover the final result.

Online 26 February 2003

 

Acta Cryst. (2003). A59, 183-192  [ doi:10.1107/S010876730300237X ]

The crystallographic fast Fourier transform. III. Centred lattices

M. Rowicka, A. Kudlicki and Z. Otwinowski

Synopsis: Algorithms for evaluation of the crystallographic FFT for crystallographic space groups containing centring operators are presented.

Online 26 February 2003

 

Acta Cryst. (2003). A59, 193-194  [ doi:10.1107/S010876730202250X ]

A formula to estimate the size of a fullerene

Y. L. Voytekhovsky

Synopsis: A formula to estimate the radius of an equiareal sphere for any C_n fullerene as a function of n is suggested. It asymptotically characterizes the series of C_n fullerenes with increasing n and is mostly adapted to the symmetric shapes. The estimated radius may also be a reasonable approximation if the shape is not too elliptic.

Online 26 February 2003

 

Acta Cryst. (2003). A59, 195-198  [ doi:10.1107/S010876730202367X ]

On the symmetry of 11-hedra

Y. L. Voytekhovsky and D. G. Stepenshchikov

Synopsis: The symmetry point-group statistics for all combinatorially non-isomorphic 11-hedra (440564 in total) are contributed in the paper for the first time. The most symmetrical shapes with 3 to 36 automorphism group orders (305 in total) are drawn in Schlegel projection and characterized by facet symbols and symmetry point groups.

Online 26 February 2003

 

Acta Cryst. (2003). A59, 199  [ doi:10.1107/S0108767303002216 ]

A new method for calculation of crystal susceptibilities for X-ray diffraction at arbitrary wavelength. Erratum

I. D. Feranchuk, L. I. Gurskii, L. I. Komarov, O. M. Lugovskaya, F. Burgäzy and A. Ulyanenkov

Synopsis: Erratum to Acta Cryst. A58, 370-384.

Online 26 February 2003

 

Acta Cryst. (2003). A59, 200  [ doi:10.1107/S0108767302020238 ]

Fundamentals of crystallography

Online 26 February 2003

 

Acta Cryst. (2003). A59, 200  [ doi:10.1107/S0108767303003805 ]

Structure determination from powder diffraction data

Online 26 February 2003