IN THIS ISSUE Rietveld Refinement from Powder Diffraction Data

Global Rietveld Refinement

Global optimisation methods of structure determination from powder diffraction data have risen to prominence in a relatively short space of time and they now constitute a key approach in the examination of polycrystalline molecular organic materials. A correctly formulated global optimisation approach may be regarded as a "global Rietveld refinement" that is capable of delivering accurate cryst...

A Rietveld refinement method for angular- and wavelength-dispersive neutron time-of-flight powder diffraction data

This paper introduces a two-dimensional extension of the well established Rietveld refinement method for modeling neutron time-of-flight powder diffraction data. The novel approach takes into account the variation of two parameters, diffraction angle 2θ and wavelength λ, to optimally adapt to the varying resolution function in diffraction experiments. By doing so, the refinement against angular...

Automated parametric Rietveld refinement and its application to two- dimensional X-ray powder diffraction experiments

Neutron powder diffraction in materials with incoherent scattering: an illustration of Rietveld refinement quality from nondeuterated gypsum

The power of the state-of-the-art neutron powder diffractometer suite at the Institut Laue–Langevin for investigating the structure of nondeuterated materials is presented using gypsum, CaSO4 2H2O, as a reference material. It is shown that flexible modern neutron powder diffraction instruments at reactorbased sources can yield data with sufficient counting statistics above the incoherent scatte...

Multidataset Refinement Resonant Diffraction, and Magnetic Structures

The scope of Rietveld and other powder diffraction refinements continues to expand, driven by improvements in instrumentation, methodology and software. This will be illustrated by examples from our research in recent years. Multidataset refinement is now commonplace; the datasets may be from different detectors, e.g., in a time-of-flight experiment, or from separate experiments, such as at sev...