Foundations of Crystallography

 

Acta Cryst. (2002). A58, 305-307  [ doi:10.1107/S0108767302008784 ]

Norio Kato (1923-2002)

J. Harada

Online 28 June 2002

 

Acta Cryst. (2002). A58, 308-315  [ doi:10.1107/S0108767302005007 ]

Structure of nanocrystalline anatase solved and refined from electron powder data

T. E. Weirich, M. Winterer, S. Seifried and J. Mayer

Synopsis: Energy-filtered Debye-Scherrer electron powder data have been succesfully employed to determine the structure of nanocrystalline anatase (TiO₂). The results obtained in the present study show for the first time that small-unit-cell structures of symmetry lower than hexagonal are directly accessible from non-textured electron powder data.

Online 28 June 2002

 

Acta Cryst. (2002). A58, 316-326  [ doi:10.1107/S010876730200510X ]

A maximum-likelihood method for global-optimization-based structure determination from powder diffraction data

A. J. Markvardsen, W. I. F. David and K. Shankland

Synopsis: A maximum-likelihood method is implemented in a powder crystal structure solution framework.

Online 28 June 2002

 

Acta Cryst. (2002). A58, 327-333  [ doi:10.1107/S0108767302005287 ]

Group-theoretical and geometrical considerations of the phase transition between the high-temperature polymorphs of quartz and tridymite

H. Sowa and E. Koch

Synopsis: A possible mechanism for the phase transition between the high-temperature polymorphs of quartz and tridymite is described by a deformation of a homogeneous sphere packing with contact number 3 formed by the Si atoms in the common subgroup P6₁22 of P6₄22 and P6₃mmc.

Online 28 June 2002

 

Acta Cryst. (2002). A58, 334-345  [ doi:10.1107/S0108767302005196 ]

Morphological possibilities in general crystallography. Snow crystals

A. Janner

Synopsis: Morphological features observed in snow crystals, like a macroscopic hexagonal lattice and pinned growth boundaries, are analyzed in the framework of a general crystallography that allows point groups of infinite order.

Online 28 June 2002

    

Acta Cryst. (2002). A58, 346-351  [ doi:10.1107/S0108767302006669 ]

Structure, odd lines and topological entropy of disorder of amorphous silicon

F. Wooten

Synopsis: The topologically stable odd-line defects are found for a continuous random network model of amorphous silicon. From these, the topological entropy of disorder is found.

Online 28 June 2002

    

Acta Cryst. (2002). A58, 352-360  [ doi:10.1107/S0108767302005202 ]

A multigrid approach to the average lattices of quasicrystals

J. L. Aragón, G. G. Naumis and M. Torres

Synopsis: The average structure of a quasilattice is calculated using the dual generalized method.

Online 28 June 2002

 

Acta Cryst. (2002). A58, 361-369  [ doi:10.1107/S0108767302005597 ]

Algebraic direct methods for few-atoms structure models

H. A. Hauptman, D. Y. Guo, H. Xu and R. H. Blessing

Synopsis: Normalized structure-factor algebra is presented for few-atoms structure models with N = 1, 2, 3, ... equal atoms or polyatomic globs per unit cell.

Online 28 June 2002

    

Acta Cryst. (2002). A58, 370-384  [ doi:10.1107/S0108767302007997 ]

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

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

Synopsis: The article presents a method for calculation of X-ray susceptibility and the Debye-Waller factor for crystals. The method improves the precision of calculated values in comparison with the presently used algorithms. The results are illustrated by numerical examples and compared with experimental data.

Online 28 June 2002

 

Acta Cryst. (2002). A58, 385-390  [ doi:10.1107/S0108767302007985 ]

Absolute structure-factor measurements of an Al-Pd-Mn quasicrystal

Y. Zhang, R. Colella, S. Kycia and A. I. Goldman

Synopsis: Several X-ray reflections from an icosahedral quasicrystal Al-Pd-Mn have been measured with great accuracy on an absolute basis by making use of Bragg-case diffraction. Anomalous transmission was found to be strong in the `good' regions of the quasicrystalline specimen and it was measured on an absolute basis, but the small residual strains present in the specimen prevented an accurate comparison between theory and experiment.

Online 28 June 2002

 

Acta Cryst. (2002). A58, 391-403  [ doi:10.1107/S0108767302008127 ]

Atomic structure of the (Al,Si)CuFe cubic approximant phase

F. Puyraimond, M. Quiquandon, D. Gratias, M. Tillard, C. Belin, A. Quivy and Y. Calvayrac

Synopsis: The crystal structure determination of the 1/1 cubic approximant of the icosahedral phase i-AlCuFe is performed by single-crystal X-ray diffraction. The refined structure is shown to agree reasonably well with the theoretical one obtained from the ideal parent quasicrystal structure by the perpendicular shear method. The 1/1 cubic approximant shares many features of the quasicrystal including large atomic clusters that extend significantly farther than the unit cell of the approximant.

Online 28 June 2002

 

Acta Cryst. (2002). A58, 404-407  [ doi:10.1107/S010876730200555X ]

On the symmetry of 9- and 10-hedra

Y. L. Voytekhovsky and D. G. Stepenshchikov

Synopsis: The symmetry point groups for all combinatorially non-isomorphic 9- and 10-hedra (2606 and 32300, respectively) are contributed for the first time.

Online 28 June 2002

 

Acta Cryst. (2002). A58, 408-409  [ doi:10.1107/S0108767302006700 ]

The Goos-Hänchen effect at Bragg diffraction

K. Tamasaku and T. Ishikawa

Synopsis: Lateral shift of the Bragg diffracted beam was measured for a spectrally narrow beam.

Online 28 June 2002

 

Acta Cryst. (2002). A58, 410-411  [ doi:10.1107/S0108767302005676 ]

Form factors for core electrons useful for the application of quantum crystallography (QCr) to organic molecules

L. Huang, L. Massa and J. Karle

Synopsis: Form factors are calculated for the core electrons of the first-row atoms B, C, N, O and F.

Online 28 June 2002

 

Acta Cryst. (2002). A58, 412  [ doi:10.1107/S0108767302009960 ]

Dynamical theory of X-ray diffraction

Online 28 June 2002

 

Acta Cryst. (2002). A58, 413-414  [ doi:10.1107/S0108767302009959 ]

Diffuse neutron scattering from crystalline materials

Online 28 June 2002

 

Acta Cryst. (2002). A58, 414  [ doi:10.1107/S0108767302009972 ]

Phonons in nanostructures

Online 28 June 2002

 

Acta Cryst. (2002). A58, 414  [ doi:10.1107/S0108767302005561 ]

Symmetry and structure

Online 28 June 2002