Re: [Ifeffit] CN and bond distances in Artemis

Hi all, Thank you very much Scott for your not slow answer and sorry for my very slow one. I think my system is a little bit complicated. I have bimetallic catalysts (PtSn) and I did fits supposing two different structures but I do not know the relative proportion of these two structures. In th

Re: [Ifeffit] CN and bond distances in Artemis

Hi Anatoly, Sorry very much Anatoly, you are right, I only told you low values for S02 but I did not give any value to you. Which is the minimum reasonable coordiantion number in a fcc structure? Yes, I assumed a fixed value of 12 for N and I left S02 as variable. I realize that my fault was to

Re: [Ifeffit] CN and bond distances in Artemis

Hi Matt, Thank you very much for your comments. S02 is a variable for me and it gives information about the size of the particles (related to coordination number). For instance, in the case of Pt foil it should be close to 0.85, however it is much smaller (0.20) in the case of platinum nanoparti

Re: [Ifeffit] CN and bond distances in Artemis

Hi all, First of all, I would like to thanks Anatoly for his file and everybody for useful comments. I have analysed Anatoly's data and I have obtained a good value for S02 = 0.85 or 0.82 (depending on the number of variables used). So, my data is the problem, and it is not my analysis, but maybe

Re: [Ifeffit] CN and bond distances in Artemis

Hi all, I did fits with self absorption corrected data (Fluo and Booth algorithms) and the value for S02 is 1.20 (0.30). It seems that I am not very lucky, if I take an average value (1.20 and 0.50), it should be ok (0.85) jeje, I am joking. Then...what can I do now? Thank you very much, Best

Re: [Ifeffit] CN and bond distances in Artemis

Ok, how can I apply an "infinite" sample correction? The other samples are measured also in fluorescence mode, then is it better to measure Ptfoil in the same conditions (fluorescence)? Thanks a lot Best regards, JA begin:vcard n:Maciá Agulló;Juan Antonio tel;fax:0034-965903454 tel;work:0034-

Re: [Ifeffit] CN and bond distances in Artemis

Hi all, I did a multiple shell fit for platinum foil and the results were similar: S02 = 0.51 and the uncertainty varies from 0.02 to 0.03 depending on the fit. Please find enclosed a file with values of energy, I0 and I of the platinum foil. I include this file if someone has curiosity on raw da

[Ifeffit] CN and bond distances in Artemis

Hi all, I read your papers Anatoly. You fixed the value of S02 found in the Pt metal, and the expression in Artemis would be like this: N:1 x S02: amp·N, right?? I have a low value of S02 in the case of platinum (0.53), how can I solve the problem? Bond distances = delR + Reff (with phase correct

Re: [Ifeffit] Coordination number

It is polemic in terms of use coordination numbers or SO2, both are connected. In fact, you calculate SO2 in Artemis but I do not how to obtain N for my catalyst. Ok, thank you very much Anatoly I am reading your papers. Best regards, JA begin:vcard n:Maciá Agulló;Juan Antonio tel;fax:0034-96

[Ifeffit] Coordination number

Hi all, I have a simple question but I am afraid it is polemic. Why people always calculate coordination numbers and bond distances and how? I have an e-mail where Bruce described perfectly how to calculate the coordiantion number for the first shell. But,...if I have bimetallic catalysts or/and

Re: [Ifeffit] Acknowledgements

Hi all, Due to the great help obtained from this forum I decide to include it in the acknowledgements of the revised paper. Maybe you are not aware of this help but you solve my doubts. I think it is the least I can do (I can not include all of you because you are too many, : )). And now, I woul

Re: [Ifeffit] Consistency criterion

Hi Scott, Thanks a lot, you are a good fortune-teller. I have low-Z scatterers (oxygen) and high-Z scatteres (Pt). Best regards, JA Scott Calvin ha escrito: > Hi Juan, > > They're consistent. The higher r-factor on the kwt-1 data might be a > clue about how reliable part of your data range is

[Ifeffit] Consistency criterion

Hi all, Scott answered my question about consistency but now I have a new doubt. I have two fits (one in k1 and other in k3 weights) with fitted parameters that have uncertainty ranges overlaped, then... in principle, they are consitent, right? But the fit in k1 weight have a R-factor too high (0

Re: [Ifeffit] k-weight in Artemis

Scott, how did you calculate bond lenth? delR + Reff? Scott Calvin wrote: > Ideally, the fitted parameters should have > uncertainty ranges that overlap. For example, one > bond length might be 2.03 +/- 0.04 angstroms, and > the equivalent bond length using a different > k-weight might be 2.09 +

Re: [Ifeffit] k-weight in Artemis

Ok Scott, thanks. JA begin:vcard n:Maciá Agulló;Juan Antonio tel;fax:0034-965903454 tel;work:0034-965909350 x-mozilla-html:FALSE org:University of Alicante;Department of Inorganic Chemistry adr:;; version:2.1 email;internet:[EMAIL PROTECTED] title:Ph. D. Student fn:Juan Antonio Maciá Agulló

Re: [Ifeffit] k-weight in Artemis

Thank you very much Scott and Bruce for your answers. Scott, when I said "strange" spectra, I mean spectra very different (compared to k3) and with sharp valley between peaks. Best regards, JA begin:vcard n:Maciá Agulló;Juan Antonio tel;fax:0034-965903454 tel;work:0034-965909350 x-mozilla-html

[Ifeffit] k-weight in Artemis

Hi all, I read in Artemis manual that a good fit must be consistent for different k-weights. When two fits (one with k1 and other with k3) are consistent? I mean, which is maximum allowed difference, 1%, 5%...between these two fits? I have done different fits changing fit k-weights and k-weight

Re: [Ifeffit] Phase corrected Fourier transforms

Thank Bruce, but I am only a beginner full of big doubts. JA > > > As other have said, the purpose of the mailing list is to have a place > to ask questions at any level about spectroscopy and data analysis. > You seem to be quite adept at starting very interesting discussions. > I think that'

Re: [Ifeffit] Phase corrected Fourier transforms

Thank you very much for your answers. It seems that phase correction is a hot topic (not hot peppers) and everybody is partially right. I will study yours answers to decide which is my favorite "team". I agree with Bruce that this is quite possibly the funniest email, better than Scott Calvin's r

[Ifeffit] Phase corrected Fourier transforms

Hi all, I have read Phase corrected Fourier transforms in Athena manual and now I have a big doubt, ¿phase correction or not in a publication? I have read also that this correction is different (more complete) in Artemis and I am not sure if I should correct also in Artemis and which path shoul

Re: [Ifeffit] Short questions

Hi Shelly, It was an unintentional good method for a quick answer and for several smiles :-). Thank you very much everybody for your interesting XAFS tutorials available. Best regards, JA begin:vcard n:Maciá Agulló;Juan Antonio tel;fax:0034-965903454 tel;work:0034-965909350 x-mozilla-html:FA

Re: [Ifeffit] Short questions

Thank very much Scott and Bruce for your answers, and sorry for the joking new "Scott's rule". JA begin:vcard n:Maciá Agulló;Juan Antonio tel;fax:0034-965903454 tel;work:0034-965909350 x-mozilla-html:FALSE org:University of Alicante;Department of Inorganic Chemistry adr:;; version:2.1 email

[Ifeffit] Short questions

Hi Ifeffit people, I have a couple of short questions for you. I used the "Scott Calvin's rule" (number of variables < 2/3*Nip) to calculate the maximum number of allowed free parameters but I read that some people use the Nyquist theorem, which are the differences between them? and, which one is