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The Inner Shell Spectroscopy (ISS) beamline on the 8-ID station at the National Synchrotron Light Source II (NSLS-II), Upton, NY, USA, is a high-throughput X-ray absorption spectroscopy beamline designed for in situ, operando, and time-resolved material characterization using high monochromatic flux and scanning speed. This contribution discusses the technical specifications of the beamline in terms of optics, heat load management, monochromator motion control, and data acquisition and processing. Results of the beamline tests demonstrating the quality of the data obtainable on the instrument, possible energy scanning speeds, as well as long-term beamline stability are shown. The ability to directly control the monochromator trajectory to define the acquisition time for each spectral region is highlighted. Examples of studies performed on the beamline are presented. The paper is concluded with a brief outlook for future developments. [ABSTRACT FROM AUTHOR]

Synchrotron X‐ray footprinting (XF) is a growing structural biology technique that leverages radiation‐induced chemical modifications via X‐ray radiolysis of water to produce hydroxyl radicals that probe changes in macromolecular structure and dynamics in solution states of interest. The X‐ray Footprinting of Biological Materials (XFP) beamline at the National Synchrotron Light Source II provides the structural biology community with access to instrumentation and expert support in the XF method, and is also a platform for development of new technological capabilities in this field. The design and implementation of a new high‐throughput endstation device based around use of a 96‐well PCR plate form factor and supporting diagnostic instrumentation for synchrotron XF is described. This development enables a pipeline for rapid comprehensive screening of the influence of sample chemistry on hydroxyl radical dose using a convenient fluorescent assay, illustrated here with a study of 26 organic compounds. The new high‐throughput endstation device and sample evaluation pipeline now available at the XFP beamline provide the worldwide structural biology community with a robust resource for carrying out well optimized synchrotron XF studies of challenging biological systems with complex sample compositions. [ABSTRACT FROM AUTHOR]

During the COVID‐19 pandemic, synchrotron beamlines were forced to limit user access. Performing routine measurements became a challenge. At the Life Science X‐ray Scattering (LiX) beamline, new instrumentation and mail‐in protocols have been developed to remove the access barrier to solution scattering measurements. Our efforts took advantage of existing instrumentation and coincided with the larger effort at NSLS‐II to support remote measurements. Given the limited staff–user interaction for mail‐in measurements, additional software tools have been developed to ensure data quality, to automate the adjustments in data processing, as users would otherwise rely on the experience of the beamline staff, and produce a summary of the initial assessments of the data. This report describes the details of these developments. [ABSTRACT FROM AUTHOR]

Sirepo, a browser‐based GUI for X‐ray source and optics simulations, is presented. Such calculations can be performed using SRW (Synchrotron Radiation Workshop), which is a physical optics computer code, allowing simulation of entire experimental beamlines using the concept of a 'virtual beamline' with accurate treatment of synchrotron radiation generation and propagation through the X‐ray optical system. SRW is interfaced with Sirepo by means of a Python application programming interface. Sirepo supports most of the optical elements currently used at beamlines, including recent developments in SRW. In particular, support is provided for the simulation of state‐of‐the‐art X‐ray beamlines, exploiting the high coherence and brightness of modern light source facilities. New scientific visualization and reporting capabilities have been recently implemented within Sirepo, as well as automatic determination of electron beam and undulator parameters. Publicly available community databases can be dynamically queried for error‐free access to material characteristics. These computational tools can be used for the development and commissioning of new X‐ray beamlines and for testing feasibility and optimization of experiments. The same interface can guide simulation on a local computer, a remote server or a high‐performance cluster. Sirepo is available online and also within the NSLS‐II firewall, with a growing number of users at other light source facilities. Our open source code is available on GitHub. Sirepo, an open‐source browser‐based interactive GUI for X‐ray source and optics simulations, performed by SRW (Synchrotron Radiation Workshop), is presented. [ABSTRACT FROM AUTHOR]

With the motivation of searching for new superconductors in the Mg–B system, we performed ab initio evolutionary searches for all the stable compounds in this binary system in the pressure range of 0–200 GPa. We found previously unknown, yet thermodynamically stable, compositions MgB3 and Mg3B10. Experimentally known MgB2 is stable in the entire pressure range 0–200 GPa, while MgB7 and MgB12 are stable at pressures below 90 GPa and 35 GPa, respectively. We predict a reentrant behavior for MgB4, which becomes unstable against decomposition into MgB2 and MgB7 at 4 GPa and then becomes stable above 61 GPa. We find ubiquity of phases with boron sandwich structures analogous to the AlB2-type structure. However, with the exception of MgB2, all other magnesium borides have low electron–phonon coupling constants λ of 0.32–0.39 and are predicted to have Tc below 3 K. [ABSTRACT FROM AUTHOR]

A previously unknown thermodynamically stable high-pressure phase of BeF2 has been predicted using the evolutionary algorithm USPEX. This phase occurs in the pressure range 18–27 GPa. Its structure has C2/c space group symmetry and contains 18 atoms in the primitive unit cell. Given the analogy between BeF2 and SiO2, silica phases have been investigated as well, but the new phase has not been observed to be thermodynamically stable for this system. However, it is found to be metastable and to have comparable energy to the known metastable phases of SiO2, suggesting a possibility of its synthesis. [ABSTRACT FROM AUTHOR]