Hi Scott, I am afraid that E0 jumps over the edge - see bmp's in the attachment (files with enot_12 means E0=12...). Hovewer 12 eV is still less than k=3 (the starting k value). Can it influence? I did also once more fit with R from 1.7 to 4A. Fits of first 2 peaks are identical - you can see in the attachment too... I hope you and anyone from the mailing list don't mind that I am attaching so many files... cheers darek
-----Original Message----- From: ifeffit-bounces@millenia.cars.aps.anl.gov [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov] On Behalf Of Scott Calvin Sent: Friday, June 19, 2009 2:49 PM To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] problem with E0 (enot) parameters
Hi Darek,
OK, so if the K, H, and O don't affect the fit much for the C and N, and the K, H, and O are returning nonsensical values, then a logical possibility is that the E0's for C and N are correct. If you add 12 eV to the E0 you chose in Athena, where in the spectrum does it fall? Is it still before the white line? If so, it seems to me you don't have a problem. If not, then we have to ponder further.
--Scott Calvin Sarah Lawrence College
On Jun 19, 2009, at 8:28 AM, Zajac, Dariusz A. wrote:
Hi Scott, look also at H and O, but for me and for this fit important are only W-C and W-C-N bondings. This sample is an reference sample for other cyano-brigded networks. So you suggest to focuse on K ions? how can it help with first 2 peaks? K is at ~5A. I have analysed in larger R space only to see how the spectrum behave. contribution from K, O etc. at k highers than 5A is for me too low to analyse it resonable for such compound. I have attached in the previus post the last version of results. Anyway, enots for C and N do not change if I am enlarging R region (when I am including next paths, also for K). about material I am quite sure ;) and crystal structure is from literature
in the attachment you will find bmp file of the fit: data, fit, bkg and K path. fitting ranges k(3-15) R(1.7-6) dk 2 dr 0.5, phase correction - first C
cheers darek
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