![[Issue Author Index]](/a/graphics/authorindexborder.gif)
![[Volume Author Index]](/a/graphics/volumeauthorindexborder.gif)
![[Cover illustration]](/a/issues/2011/03/00/graphics/coverill.gif)
|
|
|
|
Cover illustration: Polar mode GM6 (left) and antiferrodistortive mode M3-1q (right) present in the monoclinic structure of SrAl2O4, together with a graph of maximal subgroups showing their isotropy subgroups. The amplitude of mode GM6 is much larger, and ab initio calculations confirm its soft character, while distortion M3-1q is a hard mode frozen as an induced secondary distortion [Perez-Mato et al. (2010). Acta Cryst. A66, 558-590]. The mode figures were drawn using FullProf Studio [Rodriguez-Carvajal (1993). Physica B, 192, 55-69]. |
 | Acta Cryst. (2011). A67, 191-199 [ doi:10.1107/S0108767311002042 ] Structure of planar defects in tilted perovskitesR. BeanlandSynopsis: Continuity of octahedral tilting in perovskite compounds necessarily leads to different tilt structures at planar defects such as domain walls. Online 10 March 2011 |
 | Acta Cryst. (2011). A67, 200-209 [ doi:10.1107/S0108767311003357 ] Grazing-incidence small-angle X-ray scattering from a random rough surface: a self-consistent wavefunction approximationF. ChukhovskiiSynopsis: An attempt is made to go beyond the distorted-wave Born approximation by using the integral wave equation adjusted with the Green function formalism in application to the grazing-incidence small-angle X-ray (GISAX) scattering from a random rough surface. The self-consistent approximation for the wavefunction is applied to obtain a basic solution of the non-averaged integral wave equation. The analytical expressions for the reflected GISAX specular and diffuse scattering intensities are obtained using the statistical model of a random Gaussian surface in terms of the r.m.s. roughness and two-point cumulant correlation function. Online 10 March 2011 |
 | Acta Cryst. (2011). A67, 210-218 [ doi:10.1107/S0108767311005009 ] Variance of electron-density maps in space group P1C. Giacovazzo and A. MazzoneSynopsis: The variance of electron-density maps (observed, difference and hybrid) is estimated in P1 under the hypothesis that the phases are distributed about the correct values according to von Mises distributions. Online 15 March 2011 |
 | Acta Cryst. (2011). A67, 219-228 [ doi:10.1107/S0108767311004831 ] Translation calibration of inverse-kappa goniometers in macromolecular crystallographyS. Brockhauser, K. I. White, A. A. McCarthy and R. B. G. RavelliSynopsis: A rapid, easy-to-perform translation calibration procedure has been developed for use with the EMBL/ESRF mini- Online 15 March 2011 |
 | Acta Cryst. (2011). A67, 229-239 [ doi:10.1107/S0108767311005617 ] Simultaneous determination of highly precise Debye-Waller factors and multiple structure factors for chemically ordered tetragonal FePdX. H. Sang, A. Kulovits and J. WiezorekSynopsis: Large sets of highly precise and accurate structure factors and anisotropic Debye-Waller factors for the tetragonal chemically ordered and ferromagnetic intermetallic phase FePd were simultaneously obtained using multi-beam convergent-beam electron diffraction (CBED). The CBED pattern sensitivity to structure and Debye-Waller factor changes is assessed and the potential for bonding charge measurements in FePd is discussed. Online 24 March 2011 |
 | Acta Cryst. (2011). A67, 240-251 [ doi:10.1107/S0108767311006179 ] Non-crystallographic nets with freely acting, non-abelian local automorphism groupsM. Moreira de Oliveira and J.-G. EonSynopsis: An infinite family of non-crystallographic nets is constructed and analysed. Online 25 March 2011 |
 | Acta Cryst. (2011). A67, 252-263 [ doi:10.1107/S0108767311009482 ] Faulting in finite face-centered-cubic crystallitesK. R. Beyerlein, R. L. Snyder and P. ScardiSynopsis: The effects of faulting on the powder line profile are discussed, in particular considering the case of small crystalline face-centered-cubic domains. Online 12 April 2011 |
 | Acta Cryst. (2011). A67, 264-268 [ doi:10.1107/S0108767311010282 ] On the symmetry and the signature of atomic mechanisms in multiferroics: the example of Ba2CoGe2O7J. M. Perez-Mato and J. L. RibeiroSynopsis: The peculiar magnetoelectric properties of Ba2CoGe2O7 are explained by making use only of symmetry arguments and symmetry-based phenomenology. This remarkable example shows the general need for a systematic application of magnetic symmetry in the study of multiferroics. Online 12 April 2011 |
 | Acta Cryst. (2011). A67, 269-275 [ doi:10.1107/S0108767311007008 ] Exact direct-space asymmetric units for the 230 crystallographic space groupsR. W. Grosse-Kunstleve, B. Wong, M. Mustyakimov and P. D. AdamsSynopsis: A reference table of exact direct-space asymmetric units for the 230 crystallographic space groups is presented, based on a new geometric notation for asymmetric unit conditions. Online 31 March 2011 |
 | Acta Cryst. (2011). A67, 276-283 [ doi:10.1107/S0108767311007367 ] About the
|
 | Acta Cryst. (2011). A67, 284-291 [ doi:10.1107/S0108767311008087 ] A charge-flipping algorithm to handle incomplete dataG. Oszlányi and A. SütoSynopsis: A version of the charge-flipping algorithm is introduced to handle incomplete data. The efficiency of the algorithm is thoroughly tested, and it is shown that many small-molecule structures can be solved by utilizing significantly fewer data than is standard in current crystallographic practice. Online 7 April 2011 |
Acta Cryst. (2011). A67, 292-296 [ doi:10.1107/S0108767311007616 ] Conditional ambiguity of one-dimensional crystal structures determined from a minimum of diffraction intensity dataI. A. Shkel, H. S. Lee and O. V. TsodikovSynopsis: The method of elementary symmetric polynomials with a new origin definition is used to enumerate small one-dimentional crystal structures obtained from a minimum set of diffraction intensities. Online 25 March 2011 |
Acta Cryst. (2011). A67, 297-302 [ doi:10.1107/S0108767311006581 ] The quality of precession electron diffraction data is higher than necessary for structure solution of unknown crystalline phasesH. Klein and J. DavidSynopsis: It is shown that a reduction in data quality does not alter the success of structure solution of unknown crystals, with high accuracy of the cation positions. The accuracy of the light-atom positions may be slightly reduced. Online 30 March 2011 |
 | Acta Cryst. (2011). A67, 303-309 [ doi:10.1107/S0108767311009512 ] Precession electron diffraction of Mn2O3 and PbMnO2.75: solving structures where X-rays failH. KleinSynopsis: The structures of Mn2O3 and PbMnO2.75 have been solved from powder samples by precession electron diffraction data. The number of reflections measured appears to be the significant parameter for structure solution rather than precession angle, resolution limit and Lorentz-type correction. Online 7 April 2011 |
Acta Cryst. (2011). A67, 310-314 [ doi:10.1107/S0108767311009202 ] Pseudo extra reflection conditionsN. C. PopaSynopsis: The extra reflection conditions as given in International Tables for Crystallography Volume A may be violated if the atomic thermal vibrations and/or static disorder are anisotropic. Online 7 April 2011 |
![[HTML version]](/a/graphics/htmlborder.gif)
![[PDF version]](/a/graphics/pdfborder.gif)
![[Supplementary Material]](/a/graphics/supplementarymaterialsborder.gif)
![[Buy article online]](/logos/buy.gif)
![[Open access]](/a/graphics/free.gif)
![[kappa]](/logos/entities/kappa_rmgif.gif)
goniometer head and for other inverse-kappa goniometers designed for macromolecular crystallography. Regular calibration ensures the precision of experiments that rely on many degrees of freedom in crystal reorientation.![[sigma]](/logos/entities/sigma_rmgif.gif)