Instrumentation and personnel
The Chemical Crystallography laboratory is well equipped with diffractometers, microscopes and other supporting instrumentation.
Single crystal diffraction
Chemical Crystallography has three Rigaku Oxford Diffraction single crystal X-ray diffractometers: two SuperNovae A instruments and one Synergy DW.
All three are dual wavelength instruments with both molybdenum and copper targets giving wavelengths of 0.71073 Å and 1.5418 Å respectively. The molybdenum sources are used for highly absorbing samples with small unit cells, while the copper sources are better for weakly scattering samples, those with large unit cells and for absolute configuration determination.
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Powder diffraction
The Chemical Crystallography laboratory houses a PANalytical X'Pert PRO diffractometer (λ =1.5418 Å). This instrument is used for routine phase identification and analysis. In addition to the dedicated powder instrument, it is also possible to use the single crystal diffractometers to collect powder data. This is particularly useful where sample quantities are highly limited or where data are required under non-ambient conditions.
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Optical microscopy and calorimetry
In addition to four diffractometers, the Chemical Crystallgraphy facility additionally has two state-of-the-art Leica M205 C polarising Stereo-microscopes with up to 400x magnification and a 10 cm working distance. Both have digital cameras which can save images or feed to a display screen. This is particularly useful for teaching and demonstrating crystal quality, as well as for taking photographs for record or publication. The laboratory also has hot and cold stage microscopy facilities, a Thermo-Gravimetric Analyser (ambient–1200 K) and a Differential Scanning Calorimeter (100–1000 K).
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Sample environments
All three single crystal instruments are equipped with Oxford CryoSystems CryoStreams. For routine work, data are typically collected using these open flow cooling devices at 150 K and the "oil-drop method" although data can be collected in the range 80–500 K.
Additionally, the laboratory has facilities to access non-routine, "extreme" conditions with an open flow helium cooling device which can access temperatures as low as 30 K and instrumentation equipped to collect data from diamond anvil high pressure cells.
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Personnel
Amber L. Thompson
Amber is the Chemical Crystallography Service Manager and is responsible for the facility and teaching Users to collect data effectively and safely. She has been working in Oxford since 2007, before which she was in Durham. In addition to her other responsibilities, her area of expertise is the refinement of complex structures.
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Kirsten E. Christensen
Kirsten is the Analytical Service Crystallographer and is responsible for the Chemical Crystallography Analytical Service. She also supports Amber with teaching and the facilities. Kirsten has been working in Oxford since 2011, before which she worked at Diamond Light Source on Beamline I19 as a Post-doctoral Research Assistant. She has a PhD in Structural Chemistry from Stockholm University. Kirsten's area of expertise is in higher dimensional crystallography (modulation i.e. incommensurate structures) and instrumentation.
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Keith R. J. Waters
Keith provides Chemical Crystallography with technical support. He is a master of all trades with expertise in everything from IT to electronics to plumbing. Although he now semi-retired, he is an indispensable part of the Team with a vast amount of experience as he has been working in the department for fifty years.
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