For many years the CCDC maintained an experimental crystallography facility, with a particular focus on nucleic acid structures. Such work is now done in collaboration with experimental scientists. This work has a focus on difficult crystallographic structure determinations, crystallographic methods development, structure and design of framework materials (for example metal-organic frameworks) and structure of materials at high pressure.
Recent work has involved looking at ways in which to improve the methods for determining structures from powder x-ray diffraction (PXRD) data. Here the lack of experimental data in relation to standard single crystal diffraction is a significant problem and any extra information that can be supplied is highly useful. The application of torsional data as well as intermolecular interaction distances from the Cambridge Structural Database (CSD) can be crucial in turning this challenging problem into a tractable one. Work is also on-going to push the boundaries of powder structure solution in the area of metal-organic frameworks - these can be particularly complex to deal with due to high symmetry and problems with disordered guest molecules.
High pressure crystallography suffers from many of the same issues as PXRD, e.g. lack of data (due to the shading of reciprocal space by the pressure equipment) and poor resolution (due to the small sample size and absorption by the diamonds). This means that structure solution and refinement tends to be problematic and the more chemical information that can be provided (e.g. from the CSD) the better. The analysis of structures as they are compressed is also challenging and research is currently on-going into the application of different analysis techniques such as calculating interaction energies, understanding weaker, less directional interactions and studying the mechanics of phase transitions.