Acta Crystallographica Section A

Foundations of Crystallography

Volume 61, Part 3 (May 2005)

	Cover illustration: An experimentally derived plot of the Fermi hole mobility function (FHMF) for urea. The FHMF can be interpreted as a potential energy surface for electron transfer. This plot was obtained from a Hartree-Fock wavefunction constrained to fit measured X-ray diffraction structure factors, using the Tonto program. See Jayatilaka & Grimwood [Acta Cryst. (2004), A60, 111-119].

• research papers
• short communications

research papers

Acta Cryst. (2005). A61, 301-313  [ doi:10.1107/S0108767305004496 ] Absolute measurement of lattice parameter in single crystals and epitaxic layers on a double-crystal X-ray diffractometer M. Fatemi Synopsis: High-resolution measurement of absolute lattice parameter, strain and composition in single-crystal layers by the zone technique is discussed. The method enables rapid and simultaneous determination of several interplanar spacings for each layer with a potential resolution of a few parts in ten million. Online 21 April 2005

Acta Cryst. (2005). A61, 314-320  [ doi:10.1107/S0108767305005039 ] The invariom model and its application: refinement of D,L-serine at different temperatures and resolution B. Dittrich, C. B. Hübschle, M. Messerschmidt, R. Kalinowski, D. Girnt and P. Luger Synopsis: Multitemperature X-ray data for D,L-serine were evaluated using invarioms, which are theoretically derived multipole-model pseudoatoms that remain approximately invariant in an intermolecular transfer. Invariom modeling improves molecular geometry, especially for H atoms and the description of thermal motion. Online 21 April 2005

Acta Cryst. (2005). A61, 321-324  [ doi:10.1107/S0108767305006203 ] Astigmatic electron diffraction imaging: a novel mode for structure determination W. McBride, N. L. O'Leary, K. A. Nugent and L. J. Allen Synopsis: A scheme for carrying out phase reconstruction from a series of astigmatic diffraction patterns in an electron microscope is presented. Online 21 April 2005

Acta Cryst. (2005). A61, 325-330  [ doi:10.1107/S0108767305007233 ] A transition path for the pressure-induced wurtzite- to NaCl-type transformation described in Pna21 H. Sowa Synopsis: For the transition from the wurtzite to the NaCl type, a new transition path is presented that is based on the deformation of a lonsdaleite configuration into a cubic primitive lattice cP using symmetry Pnma. Online 21 April 2005

Acta Cryst. (2005). A61, 331-342  [ doi:10.1107/S0108767305007221 ] Hexagonal and trigonal sphere packings. III. Trivariant lattice complexes of hexagonal space groups H. Sowa and E. Koch Synopsis: All types of homogeneous sphere packing and interpenetrating sphere packings and layers were derived that correspond to point configurations of the 15 trivariant hexagonal lattice complexes. Examples of related crystal structures are given. Online 21 April 2005

Acta Cryst. (2005). A61, 343-349  [ doi:10.1107/S0108767305009013 ] The partial structure with errors: a probabilistic treatment R. Caliandro, B. Carrozzini, G. L. Cascarano, L. De Caro, C. Giacovazzo, M. Moustiakimov and D. Siliqi Synopsis: The case of imperfect partial structures has been revisited via the method of joint probability distribution functions. Online 21 April 2005

Acta Cryst. (2005). A61, 350-357  [ doi:10.1107/S0108767305009505 ] Statistical approach in cluster analysis of two-dimensional quasicrystals A. Dabrowska, B. Kozakowski and J. Wolny Synopsis: A new 17-atom cluster is proposed and thoroughly discussed and compared with the 33-atom Gummelt cluster. Structure factors for these clusters are calculated with a statistical approach. Online 21 April 2005

Acta Cryst. (2005). A61, 358-362  [ doi:10.1107/S0108767305009578 ] Isohedral simple tilings: binodal and by tiles with 16 faces O. Delgado-Friedrichs and M. O'Keeffe Synopsis: There are 0, 23, 136 and 710 isohedral simple tilings by tiles of <14, 14, 15 and 16 faces, respectively. Online 21 April 2005

Acta Cryst. (2005). A61, 363-372  [ doi:10.1107/S0108767305009918 ] The prior-derived F constraints in the maximum-entropy method L. Palatinus and S. van Smaalen Synopsis: The method of prior-derived F constraints is proposed as a new method to reduce artifacts and noise in electron-density maps reconstructed by the maximum-entropy method. Online 21 April 2005

Acta Cryst. (2005). A61, 373-381  [ doi:10.1107/S010876730501055X ] Diffraction with wavefront curvature: a path to unique phase recovery K. A. Nugent, A. G. Peele, H. M. Quiney and H. N. Chapman Synopsis: Modern X-ray optics can produce a focused synchrotron beam with curvature on a scale comparable to that of an isolated biomolecule or to the lattice spacing of a biomolecular crystal. It is demonstrated that diffraction of phase-curved beams from such systems allows unique and robust phase recovery. Online 21 April 2005

short communications

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