- Ifeffit - millenia.cars.aps.anl.gov

Error saving Feffit results in Filtered X(k)
by DANILO OLIVEIRA DE SOUZA 21 Feb '25

21 Feb '25

Dear Matt, Firstly, I must congratulate you for your effort in making Larch such a nice, user-friendly, intuitive tool for XAS analysis. Cheers to you and all the collaborators. And thank you for making it available for the whole community. I would like just to report a (small) issue concerning saving Feffit results using Larix. After an EXAFS fitting, I tried successfully save the graphs in every option available, i.e., k-weighted chi(k), chi(R), Real[Chi(R)] and Filtered X(k). Everything works pretty well, except the last one, where an error can be observed on the prompt: File "C:\...\Python\Python311\site-packages\larch\wxxas\feffit_panel.py", line 2211, in onSaveFit ydata = getattr(ds0.data, yname)[:nx] * xarr**kw ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~ ValueError: operands could not be broadcast together with shapes (259,) (326,)" I do not know if it happens just on my version and I know it is a minor issue, since having the window used on back-FT we can plot it easily. In any case, I am just reporting the situation for your knowledge. Cheers, Danilo OLIVEIRA DE SOUZA

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Request for proposals to host International XAFS Conference 2028
by Bare, Simon R 15 Feb '25

15 Feb '25

International XAFS Conference 2028 Proposals to host the 2028 International XAFS Conference are now solicited and accepted. Proposal guidelines are given below, but if you have questions, please contact the IXAS Chair. Proposal Deadline: June 1, 2025 Proposal Presentations (videoconference): June 1 to July 1, 2025 Announcement of 2028 venue: During the 2025 XAFS Conference in Chicago https://urldefense.us/v3/__https://xrayabsorption.org/ixas-conference-selec… Send your proposal by email to the IXAS Chair: Asakura Kiyotaka kytkaskr(a)fc.ritsumei.ac.jp<mailto:kytkaskr@fc.ritsumei.ac.jp> Proposal Guidelines The proposal submitted for the conference can be made by email to the Chair by email and should include the following information. 1. Description of Proposed Conference Venue The conference proposal should include a description of the details about the venue for the conference (based on the 600 participants, the average number of recently held conferences), including: * One conference room for plenary sessions, accommodating 600 or more attendees. * Additional space for at least 200 posters, poster presenters, and sufficient room for attendees to view and discuss posters. * Additional conference rooms for parallel sessions which can accommodate at least 200 attendees each. Close proximity of rooms is to be secured for parallel sessions. * Projection and PA systems appropriate for a scientific conference in all conference session rooms. * One or more small meeting rooms for IXAS-EC, IUCr Commission on XAFS, and related executive meetings, which accommodates at least 30 attendees. * The main conference rooms are preferred to be climate-controlled. * Compliance with local regulations for disability access. 2. Description of Organization The conference proposal should name expected members of the conference organization including Chair(s). The conference organizers should form appropriate committees with different functions such as Local Committee, Program Committee, and International Advisory Committee, and the proposal should name some of the expected members of these committees. Please include: * CV and profile of the conference chair(s) * Letter(s) of commitment for host institution(s) and any other supporting institutions. * Proposed List of Local Committee members fully committed to the organization of the conference. * Proposed List of Program Committee members representing all relevant fields and topics. * Proposed list of Fundraising Committee. * Proposed List of an International Advisory Committee formed by the IXAS-EC members and other distinguished scientists selected by Conference Organizers taking into account regional and scientific balance. * Plan for circulating conference information to XAFS communities (Web site etc.). 3. Scope and Proposed Scientific Program The conference proposal should describe the scope of the scientific program for the conference, including * expected number of parallel sessions. * fields or special topics to be highlighted * plans for any satellite meetings (scope, locations, and expected number of attendants). * list of supporting organizations (institutes and academic societies). * expected plans for an exhibition. * expected tours of nearby scientific facilities. 4. Description of Infrastructure and Logistical Plan The conference proposal should provide a list of sufficient accommodations close to the conference venue, with a range of prices and an approximate number of rooms available. Transportation options between the conference venue and accommodation sites, restaurants, regional attraction sites, social events sites, etc. should also be given, as well as a description of transportation between airports or train stations and conference venue. 5. Preliminary Budget Draft Please include projections of the total cost, income breakdown, supports from institutes and other organizations, and start-up plan. Expected ranges for registration fees should be given. Also provide any expected details about support for young scientists, scientists from developing countries, and so forth. 6. Plans for Publication Conference Organizers should circulate the full conference program to all registered attendees prior to the conference. Conference Organizers are responsible for publishing Conference Proceedings with guidance and assistance from the IXAS. It is recommended that the proceedings are published in Radiation Physics and Chemistry as first choice or J Synchrotron Radiation as second choice. Simon R Bare Distinguished Scientist Stanford Synchrotron Radiation Lightsource SLAC National Accelerator Laboratory and Adjunct Professor Chemical Engineering University of California, Davis srbare(a)slac.stanford.edu<mailto:srbare@slac.stanford.edu> Ph: 650-926-2629 https://urldefense.us/v3/__https://web.slac.stanford.edu/coaccess/__;!!G_uC… [cid:image001.jpg@01DB7FBD.A7741230][cid:image002.png@01DB7FBD.A7741230]

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Artemis: Rejects first shell fitting
by avijay＠ethz.ch 13 Feb '25

13 Feb '25

Hello all, I am trying to fit my data using Artemis for a reference foil sample. However, the fit seems to get worse when I include the scattering paths at lowest R (i.e. the first shell scattering, with the highest rank). Does it make physical sense to not include this in the fitting? Is it acceptable to try and fit only a certain range of the |X(R)| vs R for the foil reference - in order to estimate the amplitude reduction factor for subsequent fitting of the real samples? Any insight/advice is much appreciated. Thank you. Best, A

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Constraining phase composition
by Olena Zavorotynska 09 Feb '25

09 Feb '25

Hello, I have been fitting in Artemis three phases to my samples, that I denote x, y, and 1-(x+y). It often happens that x and y get unreasonable or negative values. How do I constrain x, y to be positive, and x+y < 1? On a side note, I have simple metallic lattices, and fitting two samples at the same time so have enough independent points. Best regards Olena Zavorotynska Sent from my Galaxy

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Correcting for over absorption
by cameron.mollazadeh＠colorado.edu 06 Feb '25

06 Feb '25

Hi Matthew, I was re-reading the larch documentation as my data is suffering for over absorption and was wondering how I can go about implementing the correction factor. I am primarily using the data for EXAFS analysis and was also wondering if this technique is still questionable for EXAFS. Thank you! Cameron

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Re: [EXT] Ifeffit Digest, Vol 276, Issue 2
by Christopher Chantler 05 Feb '25

05 Feb '25

Hi Cameron See Trevorah R et al. regarding correction for absorption and self-absorption; Yes it is probably still suitable for EXAFS analysis subject to other criteria and constraints. Also see Schalken M et al. for the comparison of transmission EXAFS (largely without self-absorption) versus angle-dependent fluorescence EXAFS (which almost always has self-absorption and absorption in an angle-dependent manner) and how to extract the data. Note that fluorescence data has a functional which is not directly that of a transmission or absorption measurement. Best wishes Chris -------------------------------------------------------------------------------------- Christopher Chantler, Professor, FAIP, Fellow American Physical Society Editor-in-Chief, Radiation Physics and Chemistry Member, CIT, CCN; Former Chair, International Union of Crystallography Commission on XAFS International Radiation Physics Society, Former President School of Physics, University of Melbourne, Parkville Victoria 3010 Australia +61-3-83445437 FAX +61-3-93474783 chantler(a)unimelb.edu.au<mailto:chantler@unimelb.edu.au> chantler(a)me.com<https://urldefense.us/v3/__https://owa.unimelb.edu.au/owa/redir.aspx?C=c7Bo… > https://urldefense.us/v3/__https://www.ph.unimelb.edu.au/*chantler/opticsho… <https://urldefense.us/v3/__http://www.ph.unimelb.edu.au/*chantler/home.html… > https://urldefense.us/v3/__https://www.ph.unimelb.edu.au/*chantler/opticsho… ________________________________ From: ifeffit-request(a)millenia.cars.aps.anl.gov <ifeffit-request(a)millenia.cars.aps.anl.gov> Sent: Wednesday, 5 February 2025 5:00 PM To: ifeffit(a)millenia.cars.aps.anl.gov <ifeffit(a)millenia.cars.aps.anl.gov> Subject: [EXT] Ifeffit Digest, Vol 276, Issue 2 External email: Please exercise caution Send Ifeffit mailing list submissions to ifeffit(a)millenia.cars.aps.anl.gov To subscribe or unsubscribe via email, send a message with subject or body 'help' to ifeffit-request(a)millenia.cars.aps.anl.gov You can reach the person managing the list at ifeffit-owner(a)millenia.cars.aps.anl.gov When replying, please edit your Subject line so it is more specific than "Re: Contents of Ifeffit digest..." Today's Topics: 1. Correcting for over absorption (cameron.mollazadeh(a)colorado.edu) 2. In reference to the prior overabsorption (Cameron Mollazadeh) ---------------------------------------------------------------------- Message: 1 Date: Mon, 03 Feb 2025 21:59:27 -0000 From: cameron.mollazadeh(a)colorado.edu Subject: [Ifeffit] Correcting for over absorption To: ifeffit(a)millenia.cars.aps.anl.gov Message-ID: <173861996743.2557830.8195040248000522658(a)millenia.cars.aps.anl.gov> Content-Type: text/plain; charset="utf-8" Hi Matthew, I was re-reading the larch documentation as my data is suffering for over absorption and was wondering how I can go about implementing the correction factor. I am primarily using the data for EXAFS analysis and was also wondering if this technique is still questionable for EXAFS. Thank you! Cameron ------------------------------ Message: 2 Date: Mon, 3 Feb 2025 22:01:09 +0000 From: Cameron Mollazadeh <Cameron.Mollazadeh(a)colorado.edu> Subject: [Ifeffit] In reference to the prior overabsorption To: Cameron Mollazadeh via Ifeffit <ifeffit(a)millenia.cars.aps.anl.gov> Message-ID: <SN6PR03MB4592175B3E3C1276F36D33F9F1F52(a)SN6PR03MB4592.nam prd03.prod.outlook.com> Content-Type: multipart/related; boundary="_004_SN6PR03MB459217 5B3E3C1276F36D33F9F1F52SN6PR03MB4592namp_"; type="multipart/alternative" Here is a photo of the “normalized” spectra [cid:image001.png@01DB764C.751787B0] Best, Cameron Mollazadeh PhD Student | Toney Group | CU Boulder

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In reference to the prior overabsorption
by Cameron Mollazadeh 03 Feb '25

03 Feb '25

Here is a photo of the “normalized” spectra [cid:image001.png@01DB764C.751787B0] Best, Cameron Mollazadeh PhD Student | Toney Group | CU Boulder

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Athena .dat file
by Raspante, Fabio 01 Feb '25

01 Feb '25

Hi, I worked on some data and I aligned them properly before to do any comparison. I also checked the alignment by plotting all the data together. After that I exported the data to have a file usable on Origin (the .dat format) but the problem is that after plotting the data on Origin, they are not aligned anymore. Specifically one group of data is not aligned to the others. Do you know what could be the problem? And how can I solve it? Many thanks, Fabio

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Looking for a beamline scientist-KIT Light Source, Germany
by Vitova, Tonya (INE) 31 Jan '25

31 Jan '25

Dear all, We are looking for a beamline scientist with a focus on our X-ray emission spectrometer at the ACT station, CAT-ACT beamline at the KIT Light Source, Germany. Please note that the position is initially for two years; however, we are strongly committed to extending it and offering a long-term perspective. https://www.pse.kit.edu/english/karriere/joboffer.php?id=164749 Unlike a classical user operation, the beamline scientist will support our own projects and collaborative projects. Thank you for applying or forwarding the opening to suitable candidates. All the best, Tonya Vitova -----Original Message----- From: ifeffit-request(a)millenia.cars.aps.anl.gov <ifeffit-request(a)millenia.cars.aps.anl.gov> Sent: Freitag, 31. Januar 2025 07:00 To: ifeffit(a)millenia.cars.aps.anl.gov Subject: Ifeffit Digest, Vol 275, Issue 6 Send Ifeffit mailing list submissions to ifeffit(a)millenia.cars.aps.anl.gov To subscribe or unsubscribe via email, send a message with subject or body 'help' to ifeffit-request(a)millenia.cars.aps.anl.gov You can reach the person managing the list at ifeffit-owner(a)millenia.cars.aps.anl.gov When replying, please edit your Subject line so it is more specific than "Re: Contents of Ifeffit digest..." Today's Topics: 1. Help with constrains (Otal Eugenio) 2. Re: Help with constrains (Matt Newville) ---------------------------------------------------------------------- Message: 1 Date: Thu, 30 Jan 2025 18:48:18 +0900 From: Otal Eugenio <eugenio_otal(a)shinshu-u.ac.jp> Subject: [Ifeffit] Help with constrains To: XAFS Analysis using Ifeffit <ifeffit(a)millenia.cars.aps.anl.gov> Message-ID: <CAEzOxfgjTtpfBg6bYP87pmTiQ2=otSfBVc3NAD8PNwx+z1wAUQ(a)mail.gmail.com> Content-Type: multipart/alternative; boundary="00000000000088cc25062ce95500" Hi all, I am experiencing an issue with CN and sigma2, which are correlated. My CN value is too high, and I would like to reduce it to see if I can improve the fit. I have three questions: 1. Are constraints a viable option? If not, could you clarify the alternatives? 2. The examples I found are in Python, but I am using the GUI. How should I correctly define a constraint? GPT suggested the following: max(4, 12 * exp(-sigma2_O232 / 0.02)), is it correct? 3. I attempted to apply this constraint, but now I cannot delete it. Restarting Larch for each value is not a practical solution. How can I modidy the constraint efficiently? Thank you for your help! Best regards,

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Help with constrains
by Otal Eugenio 30 Jan '25

30 Jan '25

Hi all, I am experiencing an issue with CN and sigma2, which are correlated. My CN value is too high, and I would like to reduce it to see if I can improve the fit. I have three questions: 1. Are constraints a viable option? If not, could you clarify the alternatives? 2. The examples I found are in Python, but I am using the GUI. How should I correctly define a constraint? GPT suggested the following: max(4, 12 * exp(-sigma2_O232 / 0.02)), is it correct? 3. I attempted to apply this constraint, but now I cannot delete it. Restarting Larch for each value is not a practical solution. How can I modidy the constraint efficiently? Thank you for your help! Best regards,

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