> Actually "ab initio" or whatever it is called does have a place
> in solving structure (from powder data or single crystal --
> doesn't matter) but only on the first stage when you apply
> direct methods.
Quirina Roode enquires here:
Basically, you therefore mean that obtaining an electron density
map (that is of course if we are using X-ray diffraction) is the "ab
initio" part? What are the procedures to do this for powder data?
I'm also interested if anyone has any expertise in this to
discuss determining disordered or amorphous structures (e.g. of
glasses) from powder patterns. It seems that radial distribution
functions would just allow one to confirm for example the SiO2
tetrahedral coordination for pure silicate glasses. Anyone that can
discuss Monte Carlo methods and reverse Monte Carlo methods...I would
be very appreciative.
Also I would like to add that I think it is a good idea of Armel
le Bail to keep the fire going on this list and I appreciate his
conversational style on topics. We should keep this going.
Sincerely,
Quirina
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Quirina I. Roode
PhD student: Cement Chemistry
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Department of Civil Engineering
University of the Witwatersrand
P O Wits, 2050, Johannesburg
SOUTH AFRICA
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ROODE@civen.civil.wits.ac.za
Tel: +27-(0)11-716-2478 (w)
Fax: +27-(0)11-339-1762 (w)
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