On Tuesday 25 August 2009 11:02:26 am Chris Patridge wrote:
Hello all,
After calibration, alignment and merging V K edge data, there seems to
be a large peak in R space below 1 A. From most examples and readings,
this would seem to be noise since atoms do not reside that close to each
other. Adding a background addresses this noise but then the number of
variables becomes too large and meaningless to the first shell R space
range. I believe the problem lies with the large pre edge feature seen
with high valence state Vanadium compounds. Any suggestions on how to
work through this and make realistic EXAFS analysis on these compounds.
Thanks everyone,
Didn't Richard Mayes answer this same question from you last month?
http://millenia.cars.aps.anl.gov/pipermail/ifeffit/2009-July/004365.html
In my experience, Richard's answer was spot on for V K edge data.
If Richard's good advice didn't help, then you need to be more
explicit about what the problem is, perhaps by posting a small athena
project file that demonstrates the problem.
B
Yes it is a very similar question. I did make this type of correction
by setting E0 myself. When moving to R space the data shows
significant intensity below 1 A which I thought was noise but it may
not be. Are these low A signals data or noise is my main concern
because EXAFS fitting does not fit all that well which then would point
me to my model as the problem which I think i understand.