[Ifeffit] Plotting flattened feffit simulation results

FonsPaul paul-fons at aist.go.jp
Mon Jan 28 17:12:03 CST 2019

Thank you for reply.  I am calculating structures (aka coordinates that are used for input to feff) in DFT and ultimately I simply wish to transform the k-space plot to r-space. However, I would like to plot the E(k) data for “cosmetic” reasons and the flattening is an issue there. An improper “pre-edge” subtraction will also affect the relative intensities of the Χ(R)(r) data  as well so I guess my request is not entirely for cosmetic reasons. Presumably the E(k) data in feff is already normalized (I didn’t check).

From: Ifeffit <ifeffit-bounces at millenia.cars.aps.anl.gov> on behalf of Chris Patridge <patridge at buffalo.edu>
Reply-To: XAFS Analysis using Ifeffit <ifeffit at millenia.cars.aps.anl.gov>
Date: Monday, January 28, 2019 20:18
To: XAFS Analysis using Ifeffit <ifeffit at millenia.cars.aps.anl.gov>
Subject: Re: [Ifeffit] Plotting flattened feffit simulation results


You said you averaged in E(k)?  Is this reciprocal space?  Are calculating XANES or EXAFS spectra with Feff?  You said you would transform the data to real space so I assume it is EXAFS.  I don’t think there is flattened mode in EXAFS.  If you clarify what you are calculating that might help. Are you comparing intensities between theory and experimental?  The intensities would be very different given that there was no noise in the calculations. Sorry I don’t have answers just questions.

Sent from my iPhone

On Jan 28, 2019, at 3:57 AM, FonsPaul <paul-fons at aist.go.jp<mailto:paul-fons at aist.go.jp>> wrote:
Hi All,
  I have a rather simple question and a reply for either Larch or athena would be welcome.  I have calculated a number of structures using DFT and have run feff on each of the appropriate sites and have then averaged the E(k) results.  I have no problem reading in the data to athena, however, due to the lack of a pre-edge baseline, it is typically not possible to choose a reasonable “pre-edge” baseline so that I can plot the data for the different structures in “flattened” mode. The “post-edge” baseline works very well with the default values (as there is literally no noise in the spectra).  My question is how can I induce athena to plot the E(k) data for the different structures in “flattened” mode. Ultimately, I will end up taking a Fourier transform into real space so I would also like to have a proper baseline so I can compare intensities as well.  In effect, the data from feff9 is already normalized.  Thanks for any suggestions!
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