The project is to develop instrumentation and methodologies for studying sub-100 micron crystals, using single crystal X-ray diffraction techniques and synchrotron radiation, under non-ambient conditions in order to understand structure/property correlations in a wide range of key materials ranging form sensors to pharmaceuticals. Environmental cells will be developed to apply low temperatures (below 30K), or moderate pressures at the crystal, or to expose the crystal to sound or microwaves to the crystal during data collection. Gas flow cells will also be developed so that chemical reactions between single crystals and gases can be monitored crystallographically; important applications here involve the development of gas storage devices and of establishing the nature of heterogeneous chemical reactions. Initial work will be carried out at the SRS, and then as the prototype cells are developed the instrumentation and methodologies will be transferred to the single crystal beamline, I19, on diamond, during 2008 when it becomes operational. In this way a unique facility for UK structural scientists and others will be provided, where it will be possible to study structures under change in real time. These developments will provide the users access to new techniques that are not currently possible at any other central facilities in the world.