Clifford Glenwood Shull 1915–2001

Obituary of Clifford G. Shull

Orbital ordering in LaMnO₃: estimates of structure factors and comparison of measurement methods

The orbital ordering effect of the Mn²⁺ ion on the structure factors of an LaMnO₃ crystal have been calculated. Lower-order structure-factor measurement methods such as Bragg X-ray and the QCBED method are discusssed and compared.

Concerning intensity profiles

Kinematical intensity profiles are compared with dynamical, as well as extinction-corrected, intensity distributions. Primary-extinction correction factors are discussed.

A new interpretation and practical aspects of the direct-methods modulus sum function. VIII

Thanks to a new interpretation of the direct-methods modulus sum function, its relation to other existing phase-refinement functions can be easily visualized. The behaviour of the modulus sum function has been optimized by analysing the effect of the two most important control parameters on a selection of test structures.

Lattice-parameter determination from the interaction of short femtosecond laser pulses with crystalline solids

Lattice parameters are determined from harmonic emission reflected from crystalline targets irradiated by short femtosecond laser pulses.

Multiple diffraction data analysis for macromolecular crystals in stereoscopic multibeam imaging

A detailed analysis of multiple diffraction data collected by the stereoscopic multibeam imaging technique from a tetragonal lysozyme crystal is reported. The proposed procedures provide a practical way of reconstructing diffraction profiles for experimental phase determination for macromolecular crystals.

A guided simulated annealing method for crystallography

A new optimization algorithm, the guided simulated annealing method, for use in X-ray crystallographic studies is presented.

Algebraic determination of generating functions for coordination sequences in crystal structures

Topological properties of the geodesics of a net allow an algebraic calculation of the generating function for its coordination sequences.

Experimental study on the correlation lengths of the statistical dynamical theory of X-ray diffraction by measurements of integrated intensities from silicon crystals with dislocations

Analysis of X-ray integrated intensities measured as a function of crystal thickness revealed that the two correlation lengths in the theory are absolutely required to interpret the variations of the intensities. It is shown that X-ray diffraction is more sensitive to the two correlation lengths than γ-ray diffraction.

Algorithms for deriving crystallographic space-group information. II. Treatment of special positions

Algorithms for the treatment of special positions in three-dimensional crystallographic space groups are presented.

Normal-mode analysis of the structures of perovskites with tilted octahedra

An analysis of the normal modes of vibration of a cubic perovskite that have condensed out to produce phases with tilted octahedra is presented. A Landau expansion of the excess free energy is presented involving the seven distinct modes found in the possible structures.

On the use of low-resolution data for translation search in molecular replacement

The inclusion of low-resolution reflections and taking into account a bulk-solvent correction improves drastically the signal in molecular replacement searches for the molecular position.

Latent symmetry

A theorem is introduced and applied to determine the latent symmetry of composite systems.

A simple isohedral tiling of three-dimensional space by infinite tiles and with symmetry Iad

A simple tiling of Euclidean space by infinite tiles with all hexagonal faces is described and related to a dense cylinder packing with symmetry Iad. Some related structures with the same symmetry are also described.

Nomenclature of magnetic, incommensurate, composition-changed morphotropic, polytype, transient-structural and quasicrystalline phases undergoing phase transitions. II. Report of an IUCr Working Group on Phase Transition Nomenclature. Erratum

Erratum to Acta Cryst. (2001), A57, 614–626.

Diffraction physics. Erratum

Erratum to Acta Cryst. (1998), A54, 806–819.

Report of the Executive Committee for 2000

Crystals, defects and microstructures, modeling across scales

The basics of crystallography and diffraction

Chirality in liquid crystals.

Notes for Authors