Erratum: Illustrated formalisms for total scattering data: a guide for new practitioners. Corrigendum and addendum.

[This corrects the article DOI: 10.1107/S1600576720015630.].

Illustrated formalisms for total scattering data: a guide for new practitioners.

The total scattering method is the simultaneous study of both the real- and reciprocal-space representations of diffraction data. While conventional Bragg-scattering analysis (employing methods such as Rietveld refinement) provides insight into the average structure of the material, pair distribution function (PDF) analysis allows for a more focused study of the local atomic arrangement of a material. Generically speaking, a PDF is generated by Fourier transforming the total measured reciprocal-space diffraction data (Bragg and diffuse) into a real-space representation.

POWGEN: rebuild of a third-generation powder diffractometer at the Spallation Neutron Source.

The neutron powder diffractometer POWGEN at the Spallation Neutron Source has recently (2017-2018) undergone an upgrade which resulted in an increased detector complement along with a full overhaul of the structural design of the instrument. The current instrument has a solid angular coverage of 1.2 steradians and maintains the original third-generation concept, providing a single-histogram data set over a wide -spacing range and high resolution to access large unit cells, detailed structural refinements and / measurements.

Advances in utilizing event based data structures for neutron scattering experiments.

This article strives to expand on existing work to demonstrate advancements in data processing made available using event mode measurements. Most spallation neutron sources in the world have data acquisition systems that provide event recording. The new science that is enabled by utilizing event mode has only begun to be explored.

Time-of-flight neutron total scattering with applied electric fields: and studies of ferroelectric materials.

Characterizing the structural response of functional materials (e.g., piezoelectrics and ferroelectrics) to electric fields is key for the creation of structure-property relationships.

A high precision gas flow cell for performing in situ neutron studies of local atomic structure in catalytic materials.

Gas-solid interfaces enable a multitude of industrial processes, including heterogeneous catalysis; however, there are few methods available for studying the structure of this interface under operating conditions. Here, we present a new sample environment for interrogating materials under gas-flow conditions using time-of-flight neutron scattering under both constant and pulse probe gas flow. Outlined are descriptions of the gas flow cell and a commissioning example using the adsorption of N by Ca-exchanged zeolite-X (NaCaAlSiO,x ≈ 38).

The NeXus data format.

NeXus is an effort by an international group of scientists to define a common data exchange and archival format for neutron, X-ray and muon experiments. NeXus is built on top of the scientific data format HDF5 and adds domain-specific rules for organizing data within HDF5 files, in addition to a dictionary of well defined domain-specific field names. The NeXus data format has two purposes.