Peak assignment and ionization potential with FEFF
Hi everyone, Does anyone know whether FEFF can be used to assign peaks? In other words, is there a way to tell which peaks in a calcite O K-edge spectrum are due to CO bonds and which to CaO bonds? Also, does FEFF calculate the ionization potential and if so, where does it output this? Thanks! Ross DeVol University of Madison-Wisconsin
Just to clarify, I'm working with XANES spectroscopy. Thanks Ross On 09/13/13, Ross Devol wrote:
Hi everyone,
Does anyone know whether FEFF can be used to assign peaks? In other words, is there a way to tell which peaks in a calcite O K-edge spectrum are due to CO bonds and which to CaO bonds? Also, does FEFF calculate the ionization potential and if so, where does it output this?
Thanks!
Ross DeVol University of Madison-Wisconsin _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit
Hi Ross,
The impression I get from this question (and it might be wrong) is that
you're very new to XAS and you're asking a question about a particular tool
for x-ray absorption spectroscopy prior to understanding what an x-ray
absorption spectrum actually is. If that's the case, this mailing list
might not be very helpful to you right now, as there are many other
resources for learning the basics of XAS.
-Jason
On Fri, Sep 13, 2013 at 3:38 PM, Ross Devol
Just to clarify, I'm working with XANES spectroscopy.
Thanks Ross
On 09/13/13, Ross Devol wrote:
Hi everyone,
Does anyone know whether FEFF can be used to assign peaks? In other words, is there a way to tell which peaks in a calcite O K-edge spectrum are due to CO bonds and which to CaO bonds? Also, does FEFF calculate the ionization potential and if so, where does it output this?
Thanks!
Ross DeVol University of Madison-Wisconsin _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit
Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit
On 09/13/2013 03:25 PM, Ross Devol wrote:
Does anyone know whether FEFF can be used to assign peaks? In other words, is there a way to tell which peaks in a calcite O K-edge spectrum are due to CO bonds and which to CaO bonds? Also, does FEFF calculate the ionization potential and if so, where does it output this?
Feff is a real-space multiple-scattering code. From the RSMS, your question may not make a lot of sense. The XAS spectrum is a measure of how the photoelectron interacts with its surroundings. In general, peaks in the spectrum have something to do with all of the surroundings. One way to get a handle, in some sense, on your question is to run Feff with successively larger values of the FMS parameter. That is, see what features appear or change in the calculation as you increase the radius of the cluster considered in the FMS calculation. Also of interest will be the partial densities of state as a function of cluster size. That gives some hints of how Feff sees bonding in your cluster. HTH, B -- Bruce Ravel ------------------------------------ bravel@bnl.gov National Institute of Standards and Technology Synchrotron Science Group at NSLS --- Beamlines U7A, X24A, X23A2 Building 535A Upton NY, 11973 Homepage: http://xafs.org/BruceRavel Software: https://github.com/bruceravel
participants (3)
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Bruce Ravel -
Jason Gaudet -
Ross Devol