Approximating coincidence – turning a new page for bicrystallography

The wider significance of the regularized and physically intuitive Σ function developed by Runnels [Acta Cryst. (2017), A73, 87–92] is discussed.

A projection-based reformulation of the coincident site lattice Σ for arbitrary bicrystals at finite temperature

A continuous-valued formulation of the coincident site lattice Σ is developed based on the L² inner product, taking into account temperature and arbitrary lattice rotation. Results are computed for face-centered-cubic tilt bicrystals and shown either to converge to the integer-valued Σ or to diverge to infinity.

Asymmetry in serial femtosecond crystallography data

Distribution analysis of intensity observations in serial femtosecond crystallography data processing helps to separate Bragg reflections from the background detector response.

Dynamic quantum crystallography: lattice-dynamical models refined against diffraction data. II. Applications to L-alanine, naphthalene and xylitol

The performance of a lattice-dynamical model refined against elastic Bragg scattering data is tested on L-alanine, naphthalene and xylitol.

A theoretical investigation of orientation relationships and transformation strains in steels

A unified approach to derive transformation strains and orientation-relationship models in steels is presented. This unified approach is used to derive the Nishiyama–Wassermann, Kurdjumov–Sachs and other models, and extend them naturally to the situation of a tetragonal α′ phase.

Hyperbolic crystallography of two-periodic surfaces and associated structures

The intrinsic, hyperbolic crystallography of the two-periodic, genus-two HCB and SQL surfaces is presented. All discrete groups containing the translations of the Euclidean embeddings of these surfaces are derived and examples of applications are given.

B₇ as a supergroup of crystal and quasicrystal symmetries

The practical generation of all Bravais and quasicrystal symmetries from a finite group is described.

The phase problem for one-dimensional crystals

The properties of the phase problem for a one-dimensional crystal and implications for imaging single, rod-like molecules are examined.

Monte Carlo simulation of an anharmonic Debye–Waller factor to the T⁴ order

A Taylor expansion of an anharmonic Debye–Waller factor with respect to temperature was calculated up to the fourth order with a Monte Carlo simulation, where the lattice was face-centred and the atomic interaction was described by the Lennard–Jones potential.

Douglas (Doug) Dorset (1942–2016)

Obituary for Douglas (Doug) Dorset

Report of the Executive Committee for 2015

Crystallography: A Very Short Introduction

Symmetry Through the Eyes of the Old Masters

Symmetry, Spectroscopy, and Crystallography: The Structural Nexus