Crystallography matters ... more!

The workshop will focus on the latest advances of the crystallographic methods for solving structures by both powder (Module 1) and single crystal (Module 2) diffraction data.

In particular, it will be devoted to the use of the latest versions of EXPO and SIR, two packages widely used by the international scientific community. The workshop will include theoretical and practical sessions. Participants will have the opportunity to personally use EXPO and/or SIR under the supervision of the authors.

EXPO is able to solve crystal structures by powder diffraction data using reciprocal as well as direct space methods. It is able to carry out the full pathway of the solution process, from indexing to Rietveld refinement. With respect to the previous version, it has been enriched with new powerful computing tools: e.g. the covariance principle based completion method (COVMAP) for structure model optimization; the RAndom Model based Method (RAMM) and the Hybrid Big Bang-Big Crunch approach for structure solution in reciprocal and direct space, respectively. The graphical interface has been improved making the program very user friendly.

SIR can solve ab initio crystal structures of small- and medium-size molecules, as well as protein structures, using X-ray or electron single crystal diffraction data. Several new abilities have been implemented: e.g. a new phasing method (VLD), simulated annealing techniques to exploit prior knowledge of the molecular geometry, molecular replacement methods for solving proteins, including a pipeline useful to automatically refine and complete the structure. The graphical interface has been further improved and allows the straightforward use of the program even in difficult cases.