>Are we talking about a RMC program for powder XRD data here? That would
>be very interesting. There is a list of RMC programs at
> http://www.studsvik.uu.se/rmc/rmchome.htm
>One of them is RMCPOW, "Structural refinement of crystalline materials
>based on powder diffraction data, including modelling of diffuse
>scattering". This seems really enticing, but I can't find the program on the
>referred ftp server. I am not sure if it is the same program you talked
>about.
To be sure you have to follow the advice given at this web page : 'RMC
programs under development may also be available for collaborative
studies.'
>Does Armel mean for the time being there is no free circulating RMC program
>for the powder data, although someone is working on it?
Seems to be the case. There is at least another team working on MC applied
to powder data, see J. Appl. Cryst. 29 (1996) 211-214. No trace of
circulating specific program to my knowledge, but you may build one by
combination of a Rietveld version (a lot are available with sources) and the
RMCA program source available at Studsvik which is not much complicated
to understand (try a random move, accept or reject the move).
> I wonder if
>there is even a free-to-check-out program using powder data for the
>analysis of (really) disordered structure, no matter which approach is
>adopted. I would really like to see one.
Hmmm, a book was expected entitled 'Microstructure Analysis by
Diffraction' based on lectures given at the 'X-ray Powder Diffraction
Analysis of Real Structure of Matter' (Size-Strain'95) conference. If the
Editors (R.L. Snyder and J. Fiala) are stiil reading this list, please give us a
date for publication.
>Some day we will be able to run a powder sample on a super powder
diffractometer,
>feed the data into a super computer (or just a X86), and after a couple of
>minutes, Bingo! Everything will show up on a 20'' ultra high resolution
>computer screen, everything you want to know about its structure. I
>wounder if people on board of Voyager do that as a daily routine.
At IUCr XVII conference, Seattle, I heard that the powder diffraction field
was those days one of the most evolving fields in the crystallography domain
which is more or less considered in general as rather freezed now. This is
because,
in powder diffraction, we are not yet at the 'Bingo!' state, which is never
exciting.
Armel
Armel Le Bail, Laboratoire des Fluorures URA CNRS 449
Faculte des Sciences, Universite du Maine, F-72017 Le Mans, France
http://fluo.univ-lemans.fr:8001/ and/or http://pcb4122.univ-lemans.fr/