Foundations of Crystallography

 

Acta Cryst. (2009). A65, 443-455  [ doi:10.1107/S0108767309030293 ]

Structure determination without Fourier inversion. V. A concept based on parameter space

H. Zimmermann and K. F. Fischer

Synopsis: A method of structure determination based on an equal-atom point model is described. The method avoids the phase problem, offers high resolution, works with sparse experimental data and provides all possible (quasi-)homometric solutions.

Online 17 October 2009

 

Acta Cryst. (2009). A65, 456-465  [ doi:10.1107/S0108767309030116 ]

On symmetry classes of crystal structures

H. Burzlaff and H. Zimmermann

Synopsis: An open-ended classification scheme for crystal structures based on Wyckoff sets and affine normalizer groups is proposed.

Online 17 October 2009

 

Acta Cryst. (2009). A65, 466-489  [ doi:10.1107/S0108767309028499 ]

Multiresolution of quasicrystal diffraction spectra

A. Elkharrat, J.-P. Gazeau and F. Dénoyer

Synopsis: The classification of diffraction spectra of aperiodic crystals based on multiresolution analysis is described.

Online 17 October 2009

 

Acta Cryst. (2009). A65, 490-500  [ doi:10.1107/S0108767309031729 ]

Experimental charge-density study of paracetamol - multipole refinement in the presence of a disordered methyl group

J. M. Bak, P. M. Dominiak, C. C. Wilson and K. Wozniak

Synopsis: On the basis of high-resolution single-crystal X-ray diffraction data for paracetamol, different approaches (including those based on pseudoatom databases) to modeling of the static experimental electron density in the presence of a dynamically disordered molecular fragment were tested. The electrostatic properties obtained were compared with the results of theoretical single-point periodic calculations.

Online 17 October 2009

 

Acta Cryst. (2009). A65, 501-511  [ doi:10.1107/S0108767309037702 ]

The OD interpretation of the crystal structure of kettnerite CaBiOFCO₃

J. Hybler and S. Durovic

Synopsis: The mineral kettnerite, CaBi(OFCO₃), has an order-disorder (OD) structure with a quadratic net built up by more than one kind of layer. Two maximum-degree-of-order (MDO) (1O, 2O) and one non-MDO (2Q) polytypes are derived by stacking of regularly alternating polar OD packets instead of layers. The stacking rule allows the existence of out-of-step, twin and upside-down domains.

Online 17 October 2009

 

Acta Cryst. (2009). A65, 512-527  [ doi:10.1107/S0108767309035612 ]

Molecular replacement: the probabilistic approach of the program REMO09 and its applications

R. Caliandro, B. Carrozzini, G. L. Cascarano, C. Giacovazzo, A. Mazzone and D. Siliqi

Synopsis: The method of joint probability distribution functions has been applied to molecular replacement techniques.

Online 17 October 2009

 

Acta Cryst. (2009). A65, 528-531  [ doi:10.1107/S0108767309038136 ]

Improving the direct-methods sign-unconstrained S-FFT algorithm. XV

J. Rius and C. Frontera

Synopsis: The success rate of the direct-methods sign-unconstrained S-FFT algorithm has been improved for density functions with only light scatterers. In addition, a closely related but simpler phase-refinement function is introduced, which can also treat positive and negative density peaks.

Online 17 October 2009

 

Acta Cryst. (2009). A65, 532-542  [ doi:10.1107/S0108767309037088 ]

Multiplicative congruential generators, their lattice structure, its relation to lattice-sublattice transformations and applications in crystallography

W. Hornfeck and B. Harbrecht

Synopsis: An analysis of certain types of multiplicative congruential generators - otherwise known for their application to the sequential generation of pseudo-random numbers - reveals their relation to lattice-sublattice transformations and the coordinate description of crystal structures.

Online 17 October 2009

 

Acta Cryst. (2009). A65, 543-545  [ doi:10.1107/S0108767309036125 ]

Foundations of Crystallography with Computer Applications

Online 17 October 2009

 

Acta Cryst. (2009). A65, 546  [ doi:10.1107/S0108767309042445 ]

Gjønnes Medal in Electron Crystallography - call for nominations

Online 17 October 2009

 

Acta Cryst. (2009). A65, 547-548  [ doi:10.1107/S0108767309042421 ]

Prices of IUCr journals

Online 17 October 2009