From SIR2008 to SIR2011: the role of electron diffraction

The crystal structure solution of small-medium size molecules via single crystal X-ray data is almost a routine
process. When single crystals of sufficient dimensions are not available, electron diffraction is a useful
alternative: the structure solution however may still be a challenge. We have modified the standard version of
Sir2008 to include several new tools, which are expected to make the phasing process more straightforward.
Additional work is in progress: in Sir2011, the heir of Sir2008, particular emphasis will be given to a new
procedure for the determination of the space groups, to a new approach (BEA) aiming at reducing in the
practice the disturbing effects of the dynamical scattering and to the simulated annealing algorithm, as a
phasing tool particularly useful in case of organic structures, when scarce or poor experimental data are
available.