> I know this is a Rietveld group. But could anyone tell me what is
>the smallest crystal size that is suitable for single-crystal X-ray work
>(lab X-ray and synchrotron)?
>
I'm used to work on 50 microns crystals without any problems. Solving the
structure of a smaller crystal will certainly require much time, some
skills in the field of Gandolfi analysis.
Pierre-Nicolas Schwab