Beamline I11 Research Articles

Tristan10M detector: characterization of a large area detector for time resolved experiments based on Timepix3 chip

Tristan10M is a 10-million-pixel large area detector based on the Timepix3 ASIC. The Timepix3 ASIC can work in event driven mode in addition to the standard frame based mode. Thanks to these capabilities of the Timepix3 ASIC, the Tristan detector is ideal for time-resolved experiments. The Tristan 10M detector is organized in a 2 × 5 module matrix, each module being made up of sixteen Timepix3 chips bump-bonded to a monolithic pixelated silicon sensor. In this contribution, we will report on the status of the detector development, and characterization results in terms of threshold equalization, energy calibration, and flat-field correction. A number of initial commissioning experiments have been carried out on the small molecule single crystal diffraction beamline I19 at Diamond light source, which we will also report on here. In particular, X-ray powder diffraction from a standard sample, LaB6, was performed to evaluate the inter-module alignment based on per-module basis.

An electric field cell for performing in situ single-crystal synchrotron X-ray diffraction.

With the recent increase in research into ferroelectric, anti-ferroelectric and piezoelectric materials, studying the solid-state properties in situ under applied electric fields is vital in understanding the underlying processes. Where this behaviour is the result of atomic displacements, crystallographic insight has an important role. This work presents a sample environment designed to apply an electric field to single-crystal samples in situ on the small-molecule single-crystal diffraction beamline I19, Diamond Light Source (UK). The configuration and operation of the cell is described as well as its application to studies of a proton-transfer colour-change material.

In situ study of chemical synthesis using high-energy X-ray diffraction on beamline I12 (Diamond Light Source)

<i>In situ</i> study of chemical synthesis using high-energy X-ray diffraction on beamline I12 (Diamond Light Source)

High-pressure sapphire capillary cell for synchrotron single-crystal X-ray diffraction measurements to 1500 bar

A new sapphire capillary pressure cell for single-crystal X-ray diffraction measurements at moderate pressures (200−1500 bar; 1 bar = 100 kPa) has been developed and optimized for use on beamline I19 at Diamond Light Source. The three-component cell permits optical centring of the crystal andin situpressure modification to a precision of 1 bar. Compression of hexamethylenetetramine and its deuterated analogue to 1000 bar was performed, showcasing the accuracy and precision of the measurements, and highlighting evidence of a geometric isotope effect.

Characterization of Ultrasonic Bubble Clouds in A Liquid Metal by Synchrotron X-ray High Speed Imaging and Statistical Analysis.

Quantitative understanding of the interactions of ultrasonic waves with liquid and solidifying metals is essential for developing optimal processing strategies for ultrasound processing of metal alloys in the solidification processes. In this research, we used the synchrotron X-ray high-speed imaging facility at Beamline I12 of the Diamond Light Source, UK to study the dynamics of ultrasonic bubbles in a liquid Sn-30wt%Cu alloy. A new method based on the X-ray attenuation for a white X-ray beam was developed to extract quantitative information about the bubble clouds in the chaotic and quasi-static cavitation regions. Statistical analyses were made on the bubble size distribution, and velocity distribution. Such rich statistical data provide more quantitative information about the characteristics of ultrasonic bubble clouds and cavitation in opaque, high-temperature liquid metals.

Investigation of Structural Changes during Long-Term Cycling of NCM-811 Used As Cathode Active Material in Li-Ion Batteries

Layered lithium transition metal oxides, typically containing nickel, cobalt and manganese (NCM, Li1+δ[NixCoyMnz]1-δO2 with x+y+z=1), are the most widely used cathode active material (CAM) in Li-ion batteries for portable devices and battery electric vehicles.1 The class of NCM materials has several advantageous properties such as high energy and power densities and good cycling stability. However, depending on the Ni:Co:Mn ratio, the electrochemical performance characteristics of the materials can differ significantly. Increasing the Ni content is a current research focus, as it typically allows for a higher reversible lithium usage at a given cell potential, thereby improving the specific capacity.2 At the same time, highly Ni-rich NCM materials undergo severe structural and mechanical changes, which adversely affect their cycling stability. In this respect, NCM-811 (Li1+δ[Ni0.8Co0.1Mn0.1]1-δO2) is currently one of the most Ni-rich NCM materials with proven cycling stability.3 In this work, we study the structural processes in NCM-811 over the course of 1000 cycles, cycled at a C-rate of C/2 until 4.5 V vs. Li+/Li in a pouch-cell setup at the Diamond Light Source (see Figure 1a). By means of in-situ synchrotron X-ray powder diffraction, the structural evolution of NCM-811 was monitored in regular intervals both in the completely charged and discharged state (under open circuit voltage conditions). As the lattice parameter ratio, c/a, directly correlates with the lithium amount, xLi, in the bulk material,4,5 the application of a calibration curve, xLi = f(c/a), allows for monitoring the effective capacity window of the NCM-811 CAM during cycling, and thus for clarifying the observed electrochemical capacity loss (ΔCEC, see Figure 2b). Due to an increasing cathode overpotential, the accessible capacity determined by XRD analysis becomes smaller within the fixed potential cut-offs both in the charged (ΔCcharge) and discharged state (ΔCdischarge). As the sum of these two loss terms, ΔCXRD, does not reach the actual capacity loss, ΔCEC, some fraction of the NCM-811 material has to be entirely lost during cycling (see Figure 1c). By using additional techniques such as electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy, this material loss can be assigned to a nm-thick, resistive surface layer around the primary particles. This resistive layer is in turn responsible for the observed overpotential losses. In contrast to the surface layer, the bulk material turned out to be stable, with a constant Ni disorder of ≈3% on the Li layer over 1000 cycles. For this reason, we think that future research on Ni-rich materials has to make substantial progress in controlling and stabilizing their surface properties. Figure 1: NCM-811/pre-lithiated graphite pouch-cells cycled at the Diamond Light Source over 1000 cycles at C/2 and ≈22°C in the potential window of 3.0-4.5 V vs. Li+/Li (cathode potential controlled vs. Li reference-electrode). (a) Discharge capacity of two cells. (b) Comparison of the observed electrochemical capacity loss and the losses determined by XRD analysis relative to the 18th cycle, illustrated for cell 1. (c) Absolute material loss under these cycling conditions relative to the pristine state for both cells (accounting to ≈2 mAh/g already in the 18th cycle). Acknowledgements: We want to acknowledge BASF SE for the support within the frame of its scientific network on electrochemistry and batteries. We also thank the Diamond Light Source for access to beamline I11 (Beamtime Award EE16866).

The development and exploitation of synchrotron single-crystal diffraction for chemistry and materials.

A historical account is given of the 25-year development of dedicated synchrotron beamlines for single-crystal diffraction as applied to the so-called small-molecule fields of chemistry and materials science. Designs have drawn on previous successful models in macromolecular crystallography, with appropriate modifications in view of the different properties and behaviour of the respective sample types. Key factors in making these facilities attractive and productive for users include familiarity of operational procedures and the availability of experimental techniques and features normally found in local chemical crystallography laboratories, especially for the handling of samples and processing of diffraction data. Beamlines dedicated to single-crystal diffraction rather than shared with other techniques can be optimized for effective and efficient use. The experience gained from the original design, development and exploitation of stations 9.8 and 16.2SMX at the Daresbury Laboratory Synchrotron Radiation Source and beamline 11.3.1 at the Advanced Light Source have led to highly productive current facilities at ALS beamline 12.2.1 and Diamond Light Source beamline I19, including the recent introduction of remote-access operation. Such facilities have generated and continue to provide major impact in academic and commercial research that could otherwise not be achieved, including patents and applications in pharmaceuticals, energy and gas storage systems, and government policy. This article is part of the theme issue 'Fifty years of synchrotron science: achievements and opportunities'.

In situ study of sigma phase formation in Cr-Co-Ni ternary alloys at 800°C using the long duration experiment facility at Diamond Light Source.

The new long duration experiment facility on beamline I11 at Diamond Light Source has been used to study the kinetics of sigma phase formation in three Cr-Co-Ni alloys. Diffraction data acquired during in situ exposure at 800°C for 50 d showed progressive increases in the sigma fraction. This was accompanied by changes in the proportions of the other phases, which differed markedly between the alloys studied. These results demonstrate the capabilities of the long duration facility for the study of metallurgical phenomena over periods of months to years, a capability not previously available at a synchrotron source.

Transition-Metal Migration upon Cycling in a Lithium-Rich Layered Oxide – A Long-Duration Synchrotron in Situ Study

Lithium-rich layered oxides offer an extraordinarily high gravimetric capacity of more than 250 mAh g-1, which makes this class of materials attractive as cathode material in future automotive applications.1 However, the materials suffer from several drawbacks, such as low initial coulombic efficiency, poor capacity retention and voltage fading upon cycling.2 While a lot of efforts have been put into the modification of the materials with minor success, no matter whether the modification were bulk- or surface-related,3,4 less attention has been paid to understand the underlying capacity fading mechanism. Initially, the performance drop was ascribed to oxygen release from the host structure.5,6 According to more recent Online-Electrochemical-MS7 and TEM8 studies, this process is limited to near-surface regions of the particles. However, an uneven increase of overpotentials during charge and discharge, and changes/shifts of the peaks in the differential capacity plots suggest bulk effects as the main reason of the poor cycling stability.2 Although changes in the geometry of the unit cell were not evidenced by powder or neutron diffraction so far,8 a more detailed diffraction study is still missing. This should include the analysis of transition metal migration during long-term cycling, which is frequently called spinel and/or rock-salt transformation in the literature,9 and was also proposed by theoretical studies to be the reason for the performance drop.10 Aiming at this, we cycled the lithium-rich layered oxide, x Li2MnO3∙(1-x) LiNiaCobMncO2 (a+b+c=1), versus metallic lithium at a low C-rate of C/5 (50 mA g-1) at the Long-Duration-Experiment facility of Beamline I11 at Diamond Light Source11 using a custom-made pouch cell design. We collected XRD patterns every week, alternatingly in the charged and discharged state, from several cells at an interval of 15 cycles per week (more than 7 weeks in total). On the collected long-term synchrotron in situ data we performed Rietveld analysis and detected an imbalanced electron density in difference Fourier mapping, using an ordered model structure. We quantified the transition metal migration upon cycling (i. e., the transition metal disorder) by detailed reflection profile analysis. Our data demonstrate experimentally for the first time that the transition metal migration in lithium-rich layered oxides proceeds upon cycling from the octahedral transition metal sites (Figure 1A) via tetrahedral sites in the lithium layer (Figure 1B) into octahedral lithium sites (Figure 1C). Such migration is irreversible (at least partially) and it is correlated to the irreversible discharge voltage fade. From the collected XRD data, we cannot conclude if the origin of the voltage fade is thermodynamic or kinetic, but various hypotheses will be discussed. Furthermore, a comparison with other layered metal oxides will be performed. Acknowledgement: We want to acknowledge BASF SE for the support within the frame of its scientific network on electrochemistry and batteries. D. Andre, S.-J. Kim, P. Lamp, S. F. Lux, F. Maglia, O. Paschos and B. Stiaszny, J. Mater. Chem. A, 3, 6709–6732 (2015).. R. Croy, K. G. Gallagher, M. Balasubramanian, Z. Chen, Y. Ren, D. Kim, S.-H. Kang, D. W. Dees and M. M. Thackeray , J. Phys. Chem. C, 117, 6525–6536 (2013).Z. Q. Deng and A. Manthiram, J. Phys. Chem. C, 115, 7097–7103 (2011).P. Rozier and J. M. Tarascon, J. Electrochem. Soc., 162, A2490–A2499 (2015).F. La Mantia, F. Rosciano, N. Tran, and P. Novák, J. Appl. Electrochem., 38, 893–896 (2008).A. R. Armstrong, M. Holzapfel, P. Novák, C. S. Johnson, S.-H. Kang, M. M. Thackeray, and P. G. Bruce, J. Am. Chem. Soc., 128, 8694–8698 (2006).B. Strehle, K. Kleiner, R. Jung, F. Chesneau, M. Mendez, H. A. Gasteiger, and M. Piana, J. Electrochem. Soc., 164, A400–A406 (2017).C. Genevois, H. Koga, L. Croguennec, M. Ménétrier, C. Delmas, and F. Weill, J. Phys. Chem. C, 119, 75–83 (2015).J. Hong, H. Gwon, S.-K. Jung, K. Ku, and K. Kang, J. Electrochem. Soc., 162, A2447–A2467 (2015).J. Bréger, M. Jiang, N. Dupré, Y. S. Meng, Y. Shao-Horn, G. Ceder, C. P. Grey, J. Solid State Chem., 178, 2575–2585 (2005).C. A. Murray, J. Potter, S. J. Day, A. R. Baker, S. P. Thompson, J. Kelly, C. G. Morris, S. Yang and C. C. Tang, J. Appl. Cryst. 50, 172–183 (2017). Figure 1

Remote Access Revolution: Chemical Crystallographers Enter a New Era at Diamond Light Source Beamline I19

Since the inception of the use of synchrotron radiation in the structural characterisation of crystalline materials by single-crystal diffraction in the late 20th century, the field has undergone an explosion of technological developments. These cover all aspects of the experiments performed, from the construction of the storage rings and insertion devices, to the end user functionalities in the experimental hutches. Developments in automation have most frequently been driven by the macromolecular crystallography community. The drive towards greater access to ever-brighter X-ray sources has benefited the entire field. Herein, we detail the revolution that is now occurring within the chemical crystallography community, utilising many of the tools developed by their more biologically oriented colleagues, along with specialised functionalities that are tailored to the small-molecule world. We discuss the benefits of utilising the advanced features of Diamond Light Source beamline I19 in the newly developed remote access mode and the step-change in productivity that can be established as a result.

Pioneering remote-access use of Diamond beamline I19

Pioneering remote-access use of Diamond beamline I19

A Novel Dual Air-Bearing Fixed-χ Diffractometer for Small-Molecule Single-Crystal X-ray Diffraction on Beamline I19 at Diamond Light Source

Herein, we describe the development of a novel dual air-bearing fixed-χ diffractometer for beamline I19 at Diamond Light Source. The diffractometer is designed to facilitate the rapid data collections possible with a Dectris Pilatus 2M pixel-array photon-counting detector, while allowing remote operation in conjunction with a robotic sample changer. The sphere-of-confusion is made as small as practicably possible, through the use of air-bearings for both the ω and φ axes. The design and construction of the new instrument is described in detail and an accompanying paper by Johnson et al. (also in this issue) will provide a user perspective of its operation.

A synchrotron X-radiography study of the fragmentation and refinement of primary intermetallic particles in an Al-35 Cu alloy induced by ultrasonic melt processing

The authors acknowledge financial support from the UK Engineering and Physical Science Research Council (EPSRC) for the Ultra-Cast project (grants EP/L019884/1; EP/L019825/1; EP/L019965/1). Mi also would like to acknowledge the financial support by the Royal Society Industry Fellowship awarded in 2012-2016. The experiments were performed on the Psiche beamline at Synchrotron SOLEIL, France (Proposal No. 2016076). Beamline I12 at Diamond Light Source, UK, is also thanked for loan of the high speed camera.

Transition-Metal Migration in Lithium-Rich Layered Oxides – a Long-Duration Synchrotron Study

Lithium-rich layered oxides offer an high gravimetric capacity of more than 250 mAh g-1, which makes this class of materials attractive as cathode material in future automotive applications.1 However, the materials suffer from several drawbacks such as low initial coulombic efficiency, poor capacity retention and voltage fading upon cycling.2 While a lot of efforts have been put into the modification of the materials with minor success, no matter whether the modification were bulk- or surface-related,3,4 less attention has been paid to understand the underlying capacity fading mechanism. Initially, the performance drop was ascribed to oxygen release from the host structure.5,6 According to more recent OEMS and TEM studies, this process is limited to near-surface regions of the particles.7,8 However, an uneven increase of overpotentials during charge and discharge, and changes/shifts of the peaks in the differential capacity plots suggest bulk effects as the main reason of the poor cycling stability.2 Although changes in the geometry of the unit cell were not evidenced by powder or neutron diffraction so far,8 a more detailed diffraction study is still missing. This should include the analysis of transition metal migration during long-term cycling, which is frequently called spinel and/or rock-salt transformation in the literature,9 and was also proposed by theoretical studies to be the reason for the performance drop.10 Aiming at this, we quantify the transition metal migration upon cycling by detailed reflection profile analysis and difference Fourier mapping from long-term synchrotron X-ray powder diffraction measurements. The lithium-rich layered oxide, x Li2MnO3 · (1-x) LiNiaCobMncO2 (a+b+c=1), was cycled versus metallic lithium at a low C-rate of C/5 (50 mA g-1) in a custom-made pouch cell design at the long duration experiment facility of beamline I11 at Diamond Light Source.11 XRD patterns were collected every week alternating between the charged and discharged state from several cells at an interval of 15 cycles per week (more than 7 weeks in total). Our data show that during prolonged cycling transition metals can migrate reversibly from normal octahedral sites into adjacent tetrahedral sites in the lithium layer at high states of charge (Figure 1A and B). However, we show also that they further move into octahedral sites in the lithium layer (Figure 1C). This movement is, according to the present study, irreversible. Consequently, the reversible disorder might explain the high initial capacity due to reduced lattice strain, whereas the accumulation of transition metals in the lithium layer probably causes both capacity and voltage fade by blocking the lithium diffusion pathways during cycling. Acknowledgements: We want to acknowledge BASF SE for the support within the frame of its scientific network on electrochemistry and batteries. We also thank Diamond Light Source for access to beamline I11 (Beamtime Award EE14552). 1. D. Andre et al., J. Mater. Chem. A, 3, 6709–6732 (2015). 2. J. R. Croy et al., J. Phys. Chem. C, 117, 6525–6536 (2013). 3. Z. Q. Deng and A. Manthiram, J. Phys. Chem. C, 115, 7097–7103 (2011). 4. P. Rozier and J. M. Tarascon, J. Electrochem. Soc., 162, A2490–A2499 (2015). 5. F. La Mantia, F. Rosciano, N. Tran, and P. Novák, J. Appl. Electrochem., 38, 893–896 (2008). 6. A. R. Armstrong et al., J. Am. Chem. Soc., 128, 8694–8698 (2006). 7. B. Strehle et al., J. Electrochem. Soc., 164, A400–A406 (2017). 8. C. Genevois et al., J. Phys. Chem. C, 119, 75–83 (2015). 9. J. Hong, H. Gwon, S.-K. Jung, K. Ku, and K. Kang, J. Electrochem. Soc., 162, A2447–A2467 (2015). 10. J. Bréger et al., J. Solid State Chem., 178, 2575–2585 (2005). 11. C. A. Murray et al., J. Appl. Crystallogr., 50, 172–183 (2017). Figure 1

New synchrotron powder diffraction facility for long-duration experiments.

A new synchrotron X-ray powder diffraction instrument has been built and commissioned for long-duration experiments on beamline I11 at Diamond Light Source. The concept is unique, with design features to house multiple experiments running in parallel, in particular with specific stages for sample environments to study slow kinetic systems or processes. The instrument benefits from a high-brightness X-ray beam and a large area detector. Diffraction data from the commissioning work have shown that the objectives and criteria are met. Supported by two case studies, the results from months of measurements have demonstrated the viability of this large-scale instrument, which is the world's first dedicated facility for long-term studies (weeks to years) using synchrotron radiation.

Long Duration Studies of Lithium Battery Materials Using Synchrotron X-Ray Powder Diffration

The use of in-situ X-Ray Powder diffraction for the study of new battery materials has grown in recent years, providing an insight into the effects that charge/discharges cycles have on cathode materials. These experiments are often limited to short periods of time and therefore only allow for one full charge/discharge cycle/multiple fast cycles to be observed. The result is that material characteristics may be well understood for the first cycle but little is known about the long term processes that ultimately lead to failure of the cell over longer timescales. The Long Duration Experiment (LDE) Facility on Beamline I11 at Diamond Light Source is the first of its kind, housing experiments that require periodic, in-situ monitoring over periods of months to years. It is an ideal facility for the long term study of battery materials, allowing data to be collected over many cycles. To conduct these experiments a new cell had to be developed that would allow the transmission of X-rays, while also remaining impermeable to air and moisture for a long period of time. Previous in-situ diffraction experiments of battery materials have generally involved using unconventional cells. While these are effective, they are often not stable for long periods of time and are not true representations of real-life battery systems. By modifying a standard CR2032 coin cell case, we have been able to produce a cell that fits this purpose. Laser thinning was used to reduce the thickness of a small section of the cell to 50μm, allowing sufficient X-ray transmission without compromising the integrity of the cell.

Development of a Modified Coin Cell for in-Situ, Long Duration Synchrotron X-Ray Powder Diffraction

The use of in-situ X-Ray Powder diffraction for the study of new battery materials has grown in recent years, providing an insight into the effects that charge/discharges cycles have on cathode materials. These experiments are often limited to short periods of time and therefore only allow for one full charge/discharge cycle/multiple fast cycles to be observed. The result is that material characteristics may be well understood for the first cycle but little is known about the long term processes that ultimately lead to failure of the cell over longer timescales. The Long Duration Experiment (LDE) Facility on Beamline I11 at Diamond Light Source is the first of its kind, housing experiments that require periodic, in-situ monitoring over periods of months to years. It is an ideal facility for the long term study of battery materials, allowing data to be collected over many cycles. To conduct these experiments a new cell had to be developed that would allow the transmission of X-rays, while also remaining impermeable to air and moisture for a long period of time. Previous in-situ diffraction experiments of battery materials have generally involved using unconventional cells. While these are effective, they are often not stable for long periods of time and are not true representations of real-life battery systems. By modifying a standard CR2032 coin cell case, we have been able to produce a cell that fits this purpose. Laser thinning was used to reduce the thickness of a small section of the cell to 50μm, allowing sufficient X-ray transmission without compromising the integrity of the cell.

Long Duration Studies of Li-Ion Battery Materials Using Synchrotron X-Ray Powder Diffration

The Long Duration Experiment (LDE) Facility on Beamline I11 at Diamond Light Source is the first of its kind, allowing in situ synchrotron X-ray powder diffraction (SXPD) data to be collected on a weekly basis for extended periods of time (a few months up to a few years). The facility is capable of housing multiple experiments simultaneously, and even though data are only collected at weekly intervals the experiments remain in place and all sample environments (high/low temperature, humidity, electrochemical cycling) are maintained throughout the duration of the experiment. The increasing demand for large-scale energy storage (e.g. electric vehicles) means that new materials, with much higher Li+ storage capabilities and longer lifetimes than are currently available are required to meet this demand. Many promising candidates for such materials are known but before these can become commercially available their chemical/structural stability and electrochemical cycling performance need to be well understood. In-situ powder diffraction has proven to be an extremely useful technique for just this, providing an insight into the complex chemical process that take place during charge/discharge cycling. Standard in situ experiments using existing facilities are, however, often limited to short periods of time, from a few hours up to a few (2-3) days, and therefore, only allow the first few cycles (often at accelerated charging rates) of the material to be observed. The result is that the material characteristics may be well understood for the first cycle but little is known about the long term processes that ultimately lead to failure of the cell over longer timescales. With a specially designed coin cell holder (Figure 1 inset) and dedicated multi-channel Arbin battery cyclers it is an ideal facility for the long term study of both existing and novel battery materials. This setup allows data to be collected over many hundreds of cycles at slower, more realistic, rates without the need for accelerated cycling therefore better simulating battery use under real-life conditions. To achieve this, a new in situ cell was developed through the modification of a standard CR2032 coin cell which allows for the transmission of X-rays while retaining the integrity and impermeability of the stainless steel case and therefore allowing the cell to perform well for long periods of time. Details of the facility and the modified coin cells will be presented along with preliminary results of the first long term battery studies, of a selection of Li-based electrodes (commercial and novel materials), to demonstrate the capabilities of this facility and the quality of the data produced. Figure 1

Three-dimensional rendering of otolith growth using phase contrast synchrotron tomography.

A three-dimensional computer reconstruction of a plaice Pleuronectes platessa otolith is presented from data acquired by the Diamond Light synchrotron, beamline I12, X-ray source, a high energy (53-150 keV) source particularly well suited to the study of dense objects. The data allowed non-destructive rendering of otolith structure, and for the first time allows otolith annuli (internal ring structures) to be analysed in X-ray tomographic images.

Facilities for small-molecule crystallography at synchrotron sources

Although macromolecular crystallography is a widely supported technique at synchrotron radiation facilities throughout the world, there are, in comparison, only very few beamlines dedicated to small-molecule crystallography. This limited provision is despite the increasing demand for beamtime from the chemical crystallography community and the ever greater overlap between systems that can be classed as either small macromolecules or large small molecules. In this article, a very brief overview of beamlines that support small-molecule single-crystal diffraction techniques will be given along with a more detailed description of beamline I19, a dedicated facility for small-molecule crystallography at Diamond Light Source.