Hi Lubo,
if we speak of diffraction, we have a Fourier transformation, so we
are not 100% in the direct space with any structure solution method.
However, the "structure solution in direct space" does not attempt to
work in the reciprocal space - all the manipulations are done in the
direct
Hhmmm. A method which uses a model to calculate a diffraction pattern which is
compared with observed data and the difference minimised by refining some
parameters. Then restarting the process by randomly shuffling some parameters.
I propose RRWAS - Rietveld Refinement With Atom Shuffling. Or
Hi,
I feel I have a problem with terminology. What's the right nickname for
the method of structure solution from powders, which instead of analyzing
electron (nuclear) density shuffles atoms or molecules around a cell and
compares experimental and calculated patterns ? It could be well used
How about "reciprocal methods" as opposite to "direct methods" which work in
reciprocal space?
Peter
__
Peter Zavalij
Director, X-ray Crystallographic Center
University of Maryland, College Park, MD 20742
http:/www.chem.umd.edu/crystallography
OK,
But I am sure that any deciphering is a systematic rather than a random
process. I can however agree that when such a systematic process is fueled
by drinks, some random mental leaps might play a role.
This fact, unfortunately, does not help in solving this terminology
problem - at least
>What's the right nickname for the method of structure solution from powders
In Russian we use an equivalent to 'structure decipher'.
Sometimes, however, this is really 'structure solution' when we apply vodka in
the process ;)
***
Leonid A.
Hi
Stressing the fact that these methods circumvent the phase problem by
more or less randomly shuffling atoms rather than trying to solve it
from scratch, maybe "reverse methods" would be an appropriate term,
comparably to reverse engineering.
Best Wishes,
Joachim.
Peter Y. Zavalij
