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Abstract: Lipidic cubic phases (LCPs) have emerged as successful matrixes for the crystallization of membrane proteins. Moreover, the viscous LCP also provides a highly effective delivery medium for serial femtosecond crystallography (SFX) at X-ray free-electron lasers (XFELs). Here, the adaptation of this technology to perform serial millisecond crystallography (SMX) at more widely available synchrotron microfocus beamlines is described. Compared with conventional microcrystallography, LCP-SMX eliminates the need for difficult handling of individual crystals and allows for data collection at room temperature. The technology is demonstrated by solving a structure of the light-driven proton-pump bacteriorhodopsin (bR) at a resolution of 2.4 Å. The room-temperature structure of bR is very similar to previous cryogenic structures but shows small yet distinct differences in the retinal ligand and proton-transfer pathway.

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Abstract: Topological insulator (TI) thin films of Biinline imageSeinline image and Biinline imageTeinline image have been successfully grown on amorphous fused silica (vitreous SiOinline image) substrates by molecular beam epitaxy. We find that such growth is possible and investigations by X-ray diffraction reveal good crystalline quality with a high degree of order along the c-axis. Atomic force microscopy, electron backscatter diffraction and X-ray reflectivity are used to study the surface morphology and structural film parameters. Angle-resolved photoemission spectroscopy studies confirm the existence of a topological surface state. This work shows that TI films can be grown on amorphous substrates, while maintaining the topological surface state despite the lack of in-plane rotational order of the domains. The growth on fused silica presents a promising route to detailed thermoelectric measurements of TI films, free from unwanted thermal, electrical, and piezoelectric influences from the substrate.

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Abstract: Diamond Light Source (DLS) provides a suite of world-leading beamlines for macromolecular crystallography (MX) experiments which are used by scientists from all over the world. Key to their success is an integrated approach to automating the hardware and software environments such that it is only necessary to enter the beamline hutch to change large batches of samples for the robotic sample changers. Alongside investing in automation, all beamlines are also equipped with Pilatus 6M-F detectors (25 – 100 Hz) resulting in fast data collections and high turnover of samples. Rapid downstream processing of the resulting data has been developed since this is essential to drive experimental decisions. The feedback from these pipelines needs to be made readily available to users in a timely manner and a number of tools are available for both local and remote visualization of results. Remote access to these facilities was a design requirement from the outset. Several tools have been integrated and developed to streamline the process of remote access yet give the same software environment remotely as would be experienced if the experimenter was present at the beamline. The advent of remote access for cryogenically frozen samples has led to the implementation of new shift patterns for the user programme, enabling frequent short shifts for the many groups who use DLS. Remote access to MX beamlines is also a prerequisite of many industrial clients of DLS. For the future we are moving forward with the development of remote access for insitu data collection from crystallization plates following on from the success of this method for screening and collecting data by users at the beamlines. The implementation and impact of remote access at DLS will be presented here.

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Abstract: Accurate electron density mapping is quite a common practice for crystals cooled at low temperature and accurately measured. This is not true for species under external perturbation, due to complicated experimental conditions. Studying molecular crystals in excitedstates is a challenge, Coppens(2009), and a purely experimental electron density mapping is not possible at present. So far, the samelimitation affected molecular crystals at high pressure, with only few attempts to use theoretical multipoles to fit experimental data,Fabbiani (2011). Here we report on the first unconstrained multipolar model, refined for syn-l,6;8,13 biscarbonyl[14]annulene (BCA) at P=7.7 GPa. BCA was the subject of a low temperature data collection by Destro (1995). The molecule (close to C2v symmetry) has afair aromaticity, but it progressively localizes double and single bonds as a function of pressure. At 7.7 GPa the geometrical distortionis quite evident and mirrored by the electron density. The experiment, carried out at Diamond Light Source, was possible combining:a) high energy (40 Kev) to overcome the resolution problems caused by diamond anvil cells and reduce absorption and extinction; b)microfocused beam (30 micron) to minimize spurious X-ray diffusion; c) two crystals in the DAC, to increase data coverage; d)sufficient pressure to quench atomic motion. The final agreement is obviously worse than what typically obtained at ambientpressure. However, the model is satisfactory because: a) the deformation density is sensible and in agreement with the calculated one; b) the distribution of residuals is normal and no significant error is evident. The study proves that aromatic molecules are morereactive when squeezed, in keeping with the recent theoretical study by Hoffmann et al. on benzene. The Figure shows the staticdeformation density of BCA in 3D, obtained from a multipolar model refined against the experimental structure factors.

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Abstract: We present recent developments in the accelerator design of CLARA (Compact Linear Accelerator for Research and Applications), the proposed UK FEL test facility at Daresbury Laboratory. The layout changes include a dedicated collimator in CLARA front end to provide some control over the dark current, changes to low energy diagnostics section and modifications to FEL modules. The progress in the design simulations mainly focus on injector simulations incorporating wake fields in ASTRA, comparison of using ELEGANT and CSRTRACK for the Variable Bunch Compressor and first considerations of requirement of laser heater for CLARA.