Thanks Bruce! That answers my first question. What about ionization potential? Does FEFF calculate it, or is there a way to extract it from the spectra? Thanks Ross On 09/13/13, Bruce Ravel wrote:

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 _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit