[Congress Report]Difficult structures

This session addressed problems that continue to challenge all aspects of crystal structure determination. R. Boese discussed how to get crystals of very low melting compounds and those which form plastic or glassy phases. W. Clegg discussed improving your chance of structure determination by gathering data with synchrotron radiation. R. de Gelder discussed novel ways to phase data that resist routine application by getting the maximum out of Karle Hauptman determinants.

The difficulty of validating results was discussed in S. Parkin's talk 'Expansion of Global Validation Criteria to 3-D: The RTensor'. He addressed various ways to detect possible errors in either data or structural results. A. Linden in 'Difficult Structures: Making them Fit for the Chemist' gave some general advice on how to answer delicate questions so as to prevent the chemist from drawing incorrect conclusions and at the same time persuade the Acta Cryst. Editor to accept the paper.

Paul T. Beurskens and David Watkin