September 2025 - Ifeffit - millenia.cars.aps.anl.gov

Larch 2025.3.0
by Matthew Newville 19 Sep '25

19 Sep '25

Hi Folks, A new version of Larch and the Larix GUI are now available for download and for automated update. The last message about Larch 2025.2.0 was in late May, though there were updates pushed on in late July too. Since then, there have been many updates and improvements, especially to the Larix GUI. A more complete list of changes is at https://urldefense.us/v3/__https://github.com/xraypy/xraylarch/releases/tag… (and see https://urldefense.us/v3/__https://github.com/xraypy/xraylarch/releases/tag… too), but a few of the most obvious changes include: * The “List of Groups/Files” in Larix and many related “List of Groups” windows have a richer set of options with the Right Mouse Button. All these actions also now have "keyboard shortcuts" or "accelerators" (Ctrl- / Alt- keys) that do most actions to move and select groups. This allows much faster and easier manipulation of the list of datasets. * Configuring lotting options such as linewidths, colors, themes, and so forth is easier and better. The "plot" tab is "Edit Preferences" now has (only) a "Save Plot Configuration" to save the configuration of the current Plot Window #1 (to the file ".larch/wxmplot.yaml"). From the Plot Window, you can configure these settings (themes, colors, etc) for any plot. When you are happy with those, saving them from the Larix Preferences window will save those settings for future sessions. * Saving and Loading Session Files is more robust, and saving will happen in the background, without hanging the main window. * The main Larix window now has a Title (ie, “Top Window Bar”) that shows the name of the “Current Session File”. You can change that with “Save Session As”. The Plot Windows (or most of them anyway) will have Titles that show this Session File name and the name of the Analysis Panel or Data Task window that generated the plot. If you are running 2 Larix sessions, this makes it much easier to tell what windows go together. * On startup, you may be prompted to open recently automatically saved Session files for Sessions that did not exist cleanly. There has long been a list of “autosaved sessions” that you can import, but this will tell you if any session did not close well. * 2025.2.0 introduces a Generic XY Data Analysis Panel, for non-XAS data. You can now choose any X, Y arrays for a group as the XY data, and overplot several groups of scaled or unscaled datasets. And the Curve Fit Panel allows pretty generic curve-fitting for X, Y data. There have been many bug fixes and other improvements, too. As always, Mauro Rovezzi and Shelly Kelly and her group at the APS deserve a lot of credit for either making or inspiring these changes. There have also been bug reports and pull requests from a growing number of people. The GitHub repository is really the best place for this, but thanks to everyone. Let us know if you have any questions, comments, or suggestions. --Matt

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Issue with Athena – XANES Data Cannot Be Plotted in k
by biswajit.mishra＠vsb.cz 14 Sep '25

14 Sep '25

Dear Prof., I am facing an issue while processing my XAS data in Athena. When I load my dataset (Pt foil.dat), the software shows the message: “XANES data cannot be plotted in k” and it does not generate any plots at all. From what I understand, this usually occurs if the software does not recognize the correct element or edge. However, even after checking the energy range and parameters, the problem persists. I noticed that in my session Athena automatically set the element to W (74, Tungsten, L2-edge) instead of Pt (78, L3-edge). I am not sure if this mismatch is causing the issue, but I have been unable to correct it successfully. Could you please advise me on how to resolve this problem? I have attached a screenshot of the error message for your reference. Thank you for your help. Best regards, Biswajit

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XAS spectra for K4[Fe(CN)6] and K3[Fe(CN)6]
by Charmaine Nkala 08 Sep '25

08 Sep '25

Dear all, I am looking for Fe K-edge XAS spectra for K4[Fe(CN)6] and K3[Fe(CN)6] that I can use as standards for linear combination fitting. If anyone has the data and they don't mind sharing, I would be grateful. I have checked the databases https://urldefense.us/v3/__https://ixdb.jxafs.org/__;!!G_uCfscf7eWS!foQ6c2e… and https://urldefense.us/v3/__https://xasdb.lightsource.ca/__;!!G_uCfscf7eWS!f… as previously suggested in past requests, to no avail. Thank you, in advance, for your assistance. Kind regards, Charmaine

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post-doc position in the field of X-ray and UV Photoelectron Spectroscopy at University of Nova Gorica, Slovenia
by iztok.arcon＠guest.arnes.si 05 Sep '25

05 Sep '25

Dear all, The University of Nova Gorica (Slovenia) is offering a position of assistant with PhD (postdoctoral associate) in the field of X-ray and UV photoelectron spectroscopy. Details for the applications are published on: https://ung.si/en/news/news/6929/assistant-with-phd-postdoctoral-associate-… Inquiries regarding the research work should be addressed to Prof. Giovanni De Ninno: giovanni.de.ninno(a)ung.si . Deadline for the applications is 18. 9. 2025 regards Iztok Arčon

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Elemental concentrations in XRFMap_Viewer
by Tian, Tony 05 Sep '25

05 Sep '25

Good afternoon, Thanks for the platform to address X-ray related questions. I was using XRFMap_Viewer in the Larch package to look at some uXRF data of my soil samples, and the main element of interest is Fe, and to some extent Mn too. I went through the steps to choose them (Ar was auto detected), calculate model, then fit model. Under the Composition tab, concentrations were given as in the screenshot below. The dropdown units has 3 options (ng/mm^2, wt % and ppm), but when i switch among them, none of the values changed. From a bit research online, I seem to understand there are two approaches to get absolute elemental concentrations. One is by measuring reference standards and establishing calibration curves, and the other is by fundamental parameters which is built-in in Larch (or XRFMap_Viewer in my case?). We didn't run any standards at the time. Could anyone please shed some light on how [Fe] in weight % can be computed in a built-in manner? Thank you. [cid:75a2d0c6-35d4-4136-b519-73fde6e623ad] [cid:4a98ae3b-96c2-4348-b138-4312b63ceafd] Best regards, Tony

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Symposium on Data-Driven Approaches in X-ray Absorption Spectroscopy
by Clark, Adam Hugh 04 Sep '25

04 Sep '25

Dear Colleagues, We are delighted to announce the upcoming Symposium on Data-Driven Approaches in X-ray Absorption Spectroscopy, which aims at bringing together researchers in the field of x-ray absorption spectroscopy, machine learning, and computational modelling. This symposium will focus on recent developments in data-driven and machine learning techniques for the interpretation of XANES and EXAFS spectra, enabling new insights into materials structure and dynamics from large complex operando/in situ datasets. The program will feature four themed sessions: * Data-Driven Decomposition and Spectral Extraction * Machine Learning for XANES Prediction and Analysis * Advanced Approaches to EXAFS Analysis * Bridging Simulations and Experiments with Machine Learning Date: 5th-6th January 2026 Location: ETH Zurich Hönggerberg campus, Switzerland Abstract submission deadline: 15th October 2025 Symposium Webpage: https://urldefense.us/v3/__https://indico.psi.ch/event/dataxas2026__;!!G_uC… We warmly invite your participation in this symposium and look forward to your contributions and discussions.

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