Acta Cryst. (2009). A65, 81-108
[ doi:10.1107/S0108767308040592 ]

Three-dimensional Euclidean nets from two-dimensional hyperbolic tilings: kaleidoscopic examples

S. J. Ramsden, V. Robins and S. T. Hyde

Synopsis: Systematic enumeration of tilings of the two-dimensional hyperbolic plane leads to ab initio construction of triply periodic nets via projection of the tilings onto triply periodic minimal surfaces. The technique is described in detail for kaleidoscopic tilings, projected onto the P, D and G (gyroid) minimal surfaces.

Online 28 January 2009

 

Acta Cryst. (2009). A65, 109-119
[ doi:10.1107/S010876730804186X ]

A general approach for determining the diffraction contrast factor of straight-line dislocations

J. Martinez-Garcia, M. Leoni and P. Scardi

Synopsis: A general approach for determining the diffraction contrast factor of straight-line dislocations in elastically anisotropic crystals and polycrystals is described. The new approach is illustrated with practical examples of hexagonal metals and some low-symmetry mineral phases.

Online 23 January 2009

 

Acta Cryst. (2009). A65, 120-127
[ doi:10.1107/S0108767309002803 ]

Symmetry-modified charge flipping

A. Eggeman, T. White and P. Midgley

Synopsis: The use of symmetry as an additional constraint in the charge-flipping algorithm is investigated.

Online 13 February 2009

 

Acta Cryst. (2009). A65, 128-134
[ doi:10.1107/S0108767309003237 ]

Molecular shapes from small-angle X-ray scattering: extension of the theory to higher scattering angles

V. L. Shneerson and D. K. Saldin

Synopsis: A more accurate method of calculating a molecular shape function from measured small-angle X-ray scattering over a potentially wider range of the magnitude of the momentum transfer is proposed.

Online 5 February 2009

 

Acta Cryst. (2009). A65, 135-140
[ doi:10.1107/S0108767308043316 ]

Many-beam dynamical simulation for multilayer structures without a superlattice cell

M. Ohtsuka, T. Yamazaki, I. Hashimoto and K. Watanabe

Synopsis: A new many-beam dynamical theory for plan-view high-resolution transmission electron microscopy images of multilayer systems without the limitation of a superlattice cell is proposed. Simulations using this method revealed that characteristic moiré-like lattice fringes are formed due to the relative shift of the crystal-lattice planes.

Online 27 January 2009

 

Acta Cryst. (2009). A65, 141-144
[ doi:10.1107/S0108767309000531 ]

The topologies of the charge densities in Zr and Ru

T. E. Jones and M. E. Eberhart

Synopsis: The topologies of the charge densities in the hexagonal close-packed metals Ru and Zr are shown to be different.

Online 27 January 2009

 

Acta Cryst. (2009). A65, 145-155
[ doi:10.1107/S0108767308039007 ]

Comments on tables of magnetic space groups

H. Grimmer

Synopsis: It is shown how the diagrams of symmetry elements given by Litvin [Acta Cryst. (2008), A64, 419-424 and supplementary material] can be interpreted in terms of Belov-Neronova-Smirnova symbols instead of the Opechowski-Guccione symbols favoured by Litvin.

Online 23 January 2009

 

Acta Cryst. (2009). A65, 156-163
[ doi:10.1107/S010876730804333X ]

Sublattice enumeration. IV. Equivalence classes of plane sublattices by parent Patterson symmetry and colour lattice group type

J. S. Rutherford

Synopsis: Generating functions are given for the number of nonequivalent sublattices of a parent lattice of given plane symmetry.

Online 23 January 2009

 

Acta Cryst. (2009). A65, 164-166
[ doi:10.1107/S0108767309002013 ]

Crystallography and the World of Symmetry

Online 13 February 2009