3.1.2- Synchrotron data

Minimal FWHMs decrease down to 0.06 or even 0.02-0.01° 2-theta.

Multiply the maximum volumes
(previously listed for minimal FWHM ~ 0.12° 2-theta)
by 2 or 6 or 12.

This is much more comfortable than with conventional X-ray data.

It can be expected really to play with 150-300 independent atoms, corresponding to 450-900 xyz refinable parameters.

Up to 10000 or more reflections could be extracted from a synchrotron powder pattern.

Triclinic centrosymmetrical cells with up to 6000 Å3 volume or cubic cells with F lattice as large as 600000 Å3 are the theoretical upper limits which one could expect to attain by using high resolution synchrotron data !

No study has approached such limits up to now.

Largest problems solved
(up to 60 independent atoms, 180 xyz parameters refined)
are already considerable.

A list of complex experimental cases already published
may be found as a Top 50
inside the SDPD-Databank.

The maximal limits suggested for conventional in-laboratory diffractometers have been already reached without too much difficulties for triclinic, monoclinic or orthorhombic cells.

Consequently, one can predict exceptional results in a very near future from synchrotron data.