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

Influit Energy - Materials Scientist - X-ray Characterization Specialist
by Carlo Segre 03 Jun '25

03 Jun '25

Influit Energy is a dynamic and rapidly expanding company, developing energy storage solutions through cutting-edge research in battery technology, nanomaterials, and materials science. Please see the job posting at Influit Eneergy - Materials Scientist Position <https://urldefense.us/v3/__https://jobs.gusto.com/postings/influit-energy-i… > -- Carlo U. Segre, CTO Influit Energy, LLC 2312 W. Warren Blvd. Chicago, IL 60612

2 2

Larch 2025.2.0
by Matt Newville 27 May '25

27 May '25

Hi Folks, Larch 2025.2.0 has been released, with many fixes and improvements in the past few months, especially for the Larix GUI application. When running Larix, you should be prompted to run the "Update Larch" program. Some of the changes for this release include: - The Plotting section for the XAS Normalization panel has changed to give fewer "main plotting options", but then additional options for pre-edge lines, derivatives, etc. - The Plotting section for the EXAFS panel has also changed. Here, the choices for what to plot are now organized by "Space": Energy, k (including filtered or q), and R. Because there are many choices for making 2 plots at a time, the options can be saved and recalled later (including in later sessions). - There are several improvements for reading and showing non-XAS or "XY data". - There is an initial working version of a generic Curve Fitting Panel for XY and XAS data. This is similar to the Pre-edge Peak Fitting Panel, but it does not require the removal of a baseline first. - There is now an "XAS Mode" selection when importing data from plain Column Files. Currently, the choices are "Unknown", "Transmission", "Fluorescence", "HERFD", and "Calculation". The intent is to allow adjusting normalization and analysis parameters based on this Mode. Currently, only "Calculation" actually adjusts the normalization parameters. - Reading in XAS calculations from Feff (xmu.dat) or FDMNES with "Mode=Calculation" gives better pre-edge (using only the first point) and normalization. There are many more bug fixes and improvements detailed at See https://urldefense.us/v3/__https://github.com/xraypy/xraylarch/releases/tag… . There are plenty of people to thank for these fixes, but special thanks again goes to Mauro Rovezzi and Shelly Kelly. --Matt PS: We have missed a few recent Developers+Interested Users meetings. I think we should get back to having these, but maybe at a different pace. If anybody would like to discuss development or features in more detail, let me know.

1 0

Cancellation of the 19th International XAFS conference in 2025 in Chicago
by Matthew Newville 15 Apr '25

15 Apr '25

Hi All, Some of you may not have heard this yet. The International X-ray Absorption Society and the Conference organizers have canceled the XAFS19 Conference scheduled for July 14-19, 2025. From Professor Asakura, Chair of the IXAS: Dear all involved with XAFS, As you may know, the 19th International XAFS conference (XAFS 19) was scheduled to occur in Chicago from the 14th to the 19th of July 2025. After considering the many uncertainties with hosting an international conference in the US given the current political climate, the organizer of the 19-XAFS conference proposed its postponement. The IXAS EC voted on the subject and unanimously voted to cancel the 19-XAFS in Chicago in 2025. We appreciate your kind understanding. We will now call for a bid to host the conference next year, XAFS 2026, and we will decide on the new venue and communicate the decision to the community as soon as possible. Please contact the IXAS chair, Kiyotaka Asakura (kytkaskr(a)fc.ritsumei.ac.jp<mailto:kytkaskr@fc.ritsumei.ac.jp>), if you are interested in organizing the XAFS 2026. Thanks. Kiyotaka Asakura IXAS Chair Carlo Segre Chair of the 19-XAFS Also See XAFS19 homepage https://urldefense.us/v3/__https://www.icdd.com/xafs19/__;!!G_uCfscf7eWS!dg…

1 0

XAS spectra for Na2CoP2O7, Li2CoP2O7, NaCoPO4 and LiCoPO4
by Carlos Triana Estupinan 15 Apr '25

15 Apr '25

Dear Colleagues, I was curious if anyone has XAS spectra for Na2CoP2O7, Li2CoP2O7, NaCoPO4 and LiCoPO4 that you would not mind sharing. Thanks and Best Regards, -- ______________________________________ Phd. - Lic.Phil. - Msc. & Bsc. in Sciences Physics Senior Researcher, University of Zurich Department of Chemistry Winterthurerstrasse 190, CH-8057 Zurich, Switzerland Email: carlos.triana(a)chem.uzh.ch Phone: +41 44 63 54 646 Movil: +41 076 814 41 60 -- *Aviso legal:* El contenido de este mensaje y los archivos adjuntos son confidenciales y de uso exclusivo de la Universidad Nacional de Colombia. Se encuentran dirigidos sólo para el uso del destinatario al cual van enviados. La reproducción, lectura y/o copia se encuentran prohibidas a cualquier persona diferente a este y puede ser ilegal. Si usted lo ha recibido por error, infórmenos y elimínelo de su correo. Los Datos Personales serán tratados conforme a la Ley 1581 de 2012 y a nuestra Política de Datos Personales que podrá consultar en la página web https://urldefense.us/v3/__http://www.unal.edu.co__;!!G_uCfscf7eWS!eoeeN3SW… <https://urldefense.us/v3/__http://www.unal.edu.co/__;!!G_uCfscf7eWS!eoeeN3S… >.* *Las opiniones, informaciones, conclusiones y cualquier otro tipo de dato contenido en este correo electrónico, no relacionados con la actividad de la Universidad Nacional de Colombia, se entenderá como personales y de ninguna manera son avaladas por la Universidad.

2 1

A warning about feff8 vs feff6
by Joshua J. Kas 11 Apr '25

11 Apr '25

Dear ifeffit community, While doing some fitting of theoretically produced data, we noticed that there are some differences between feff6 and feff8, even when all settings are the same as far as we can tell. This was expected for some parameters such as the E0 shift, since the approximation has changed from feff6 to feff8. However, there is also a difference in the scattering amplitudes. In particular, for the Pt case that we are looking at, the nearest neighbor scattering amplitudes from feff8,9, and 10 are roughly 11/12 the size of the scattering amplitudes from feff6. This likely has something to do with a difference in the prescription to create the muffin-tin potentials, but we haven't tracked down the difference completely. In any case, as found by Bruce Ravel <https://urldefense.us/v3/__http://bruceravel.github.io/SCFtests/scf.html__;… >, differences in physical parameters between feff6 and feff8 are within errors of each other when each code is used consistently. This message is mainly meant to warn people not to mix the two codes when doing analysis. For example, an s02 extracted by fitting data with feff6 cannot be used with a feff8 analysis. -- Joshua Kas (He/Him/His) Research Assistant Professor University of Washington

1 0

CLS Introduction to X-ray absorption spectroscopy and microprobe Worksop
by Amani Ebrahim 10 Apr '25

10 Apr '25

Dear Ifeffit community, The CLS is organizing a 2-day workshop/ summer school for new commers to XAS, with a specific focus on topics such as food, soil and environmental science (see following link<https://urldefense.us/v3/__https://event.fourwaves.com/cls-xas-workshop/pag… >). Please help disseminate amongst your network. Deadline to apply is May 15. For details on the workshop, please visit: Intro to XAS and microprobe workshop<https://urldefense.us/v3/__https://event.fourwaves.com/cls-xas-workshop/pag… > Thank you from the workshop organizers ----------------------------------------------- Amani M. Ebrahim, PhD (She/Her) Associate Scientist | Canadian Light Source Ph: 306-657-3659 | C: 306-227-7228 https://urldefense.us/v3/__https://bioxas-spectroscopy.lightsource.ca/__;!!… lightsource.ca<https://urldefense.us/v3/__https://www.lightsource.ca/__;!!G_uCfscf7eWS!c8d… > | @canlightsource [AE4A24CF] [5A8E16B5][12A76F8B][601FFCD1][8CA6807][EDA296AD][CF6D0A43] We acknowledge we are on Treaty Six territory and the traditional homeland of the Métis. We pay our respects to the First Nations and Métis ancestors of this place and reaffirm our relationship with one another.

1 0

Delete me
by Richard Brand 01 Apr '25

01 Apr '25

Von meinem iPad gesendet New iPhone +49 159 06238965 New eMail brand.richard(a)web.de

1 0

XAFS19 Abstract Submissions open
by Carlo Segre 17 Mar '25

17 Mar '25

Hello All, The abstract submission page on the XAFS19 Conference web site will be open later this afternoon. You will be able to request a poster or oral presentation. The Program Committee will make the final decisions on which format your work will be presented. For those of you who need an invitation letter for a Visa, please email xafsconference2025(a)gmail.com to request one with your abstract number. For the XAFS19<https://urldefense.us/v3/__https://www.icdd.com/xafs19/__;!!G_uCfscf7eWS!Zj… > organizing committee, Carlo -- Carlo Segre, Duchossois Professor of Physics Illinois Institute of Technology

1 0

PostDoc position as Beamline Scientist at KIT Light Source
by Zimina, Anna (IKFT) 14 Mar '25

14 Mar '25

Dear all, Postdoc position for the challenging job at KIT Light Source synchtrotron as beamline scientist at the X-ray absorption spectroscopy beamline is open in our group at IKFT/KIT: https://www.pse.kit.edu/english/karriere/joboffer.php?id=164965 Curious? Find out more here: https://www.ikft.kit.edu/english/234.php Please forward the advertisement further. Thank you in advance, Anna Zimina ____________________________________________________________________________ __________ Karlsruhe Institute of Technology (KIT) Institute of Catalysis Research and Technology (IKFT) Dr. Anna Zimina Catalysis at KIT Light Source group Hermann-von-Helmholtz-Platz 1 Building 345 Office 304 76344 Eggenstein-Leopoldshafen Phone: +49 721 608 28673 Fax: +49 721 608 26789 E-Mail <mailto:anna.zimina@kit.edu> anna.zimina(a)kit.edu

1 0

XANES reference Spectra of V2O5 and VO2
by Dooshaye Moonshiram 14 Mar '25

14 Mar '25

5 6

Athena - LCF component export error
by miranda.vu＠lightsource.ca 10 Mar '25

10 Mar '25

Hi, I am having an issue with the export of LCF data in Athena version 0.9.26. When I export the .lcf of files, it will re-order the components without properly re-ordering the associated data columns. The data and components will plot correctly in Athena before exporting. Is this something that can be fixed? Or if not would it be possible for me to get version 0.9.24 if you still have a copy of it? Please let me know if there is any additional information that I can provide. Thanks, Miranda

3 3

International XAFS Conference 19 - Chicago July 14-18, 2025
by Carlo Segre 05 Mar '25

05 Mar '25

Hello IFEFFIT Mailing List, I am pleased to let you know that the website and registration pages for the XAFS19 conference to be held on the Illinois Tech Main Campus in Chicago, Illinois, July 14-18 is now available. The links to the registration for participants and exhibitors are both live and we are able to take registration. Members of the International XAFS Society can take advantage of the discount on the full participant registration fee with a promotion code that will be available shortly from the Society. The Abstract submission will open early next week and I will send an additional announcement out at that time. Please bear with us as the web site is still a work in progress. Housing information as well as more information regarding invited speakers is forthcoming. The link to the main conference web site is https://urldefense.us/v3/__https://www.icdd.com/xafs19/__;!!G_uCfscf7eWS!cy… . Please feel free to disseminate this announcement. For any questions, please email the conference at <xafsconference2025(a)gmail.com>. This email will be used for individual correspondence. If you have corrections about the web site, please feel free to email me at <segre(a)iit.edu>. Carlo Segre for the XAFS19 Local Organizing Committee -- Carlo Segre, Duchossois Professor of Physics Illinois Institute of Technology

1 0

Water-free binder advice
by Paul Aronstein 01 Mar '25

01 Mar '25

Hello, I'm looking for some advice on binder alternatives for preparing either pellets or packed powder samples in a dry glovebox. Please also note if the binder requires preparation (i.e. desiccated prior to use, etc) or if there are other considerations. Thank you, -Paul

3 3

Question about Ti edge
by Benito Melas 01 Mar '25

01 Mar '25

Hi all, I was following this article about Li2TiS3 https://urldefense.us/v3/__https://pubs.acs.org/doi/full/10.1021/acs.inorgc… and found this Ti edge XANES figure [image: image.png] The authors claim The peak position for LTS-213 is approximately 4970 eV, which agrees well > with that for rutile TiO2 with a valence of titanium species in the 4+ > oxidation state. Should we use the pre-edge to determine the oxidation state? Is it reliable, or should we use E₀ and compare it with references of well-known oxidation states? > In addition, TiS2, in which titanium is also in the 4+ oxidation state, > shows pre-edge peaks at 4968–4971 eV. (21) Considering the titanium > oxidation state in the raw materials, the stability of the titanium > species, and the XANES results, the oxidation state of the titanium species > in LTS-213 is likely to be 4+. The second conclusion is even more unclear. Would you help me see if I am missing something in my understanding of oxidation states using XANES? Best, B.

4 7

Re: Question about Ti edge
by Benito Melas 28 Feb '25

28 Feb '25

Hi Matt, Thank you for the explanation. In this case, comparing oxides provides only a rough approximation of the oxidation states. Using both oxides and sulfides would incorporate the contribution of covalency and lead to inaccuracies. What about utilizing the pre-edge mixing oxides and sulfides? I have a concept that is more related to the symmetry of the site, although this understanding also originates from oxides. Best regards, On Fri, Feb 28, 2025 at 11:54 PM matt.newville(a)gmail.com < matt.newville(a)gmail.com> wrote: > Hi Benito, > > > > The energy of the sharp rise (ie, the energy of the empty metal 4p states) > is a simple measure of the “charge state” or “oxidation state” of a > metal. To be clear, for a particular ligand type (say, oxygen), the > energy of 4p states, and so also the energy of the main rise in mu(E), will > change systematically with energy. But if you change the ligand, and the > covalency/ionicity of the bond, that will also move the energy of the > metal’s 4p states. Metal sulfides are much more covalent than metal > sulfides, and many are semi-metallic. If I understand correctly, titanium > disulfide is used because it is electrically conductive. > > > > OTOH, titanium dioxide will have a band gap of a couple of eV. That “band > gap” is strongly correlated with the edge shift. > > > > Again, the energy of the “main edge” is just not a simple measure of > “oxidation state”, especially if the ligand is not oxygen. > > Using the term “oxidation state” for a sulfide is not going to give you > much insight. > > > > --Matt > > > > > > *From: *Benito Melas <metal.cnea(a)gmail.com> > *Date: *Friday, February 28, 2025 at 7:58 AM > *To: *matt.newville(a)gmail.com <matt.newville(a)gmail.com> > *Subject: *Re: [Ifeffit] Question about Ti edge > > Hi Matt, > As you mentioned, "for the transition metals, there will usually be a > sharp rise in mu(E) at the energy." > In the case of LTS, however, this sharp rise occurs at lower energies than > in TiO2, which raises concerns regarding the claim that both compounds > exhibit the same oxidation state. > Thank you for your continued dedication to enlightening our community. > Best regards, > > > > > > > > On Fri, Feb 28, 2025 at 3:46 AM matt.newville(a)gmail.com < > matt.newville(a)gmail.com> wrote: > > Hi Benito, > > > > > The authors claim > > >> The peak position for LTS-213 is approximately 4970 eV, which agrees > well with that for rutile TiO2 with a valence of titanium species in the 4+ > oxidation state. > > > > > Should we use the pre-edge to determine the oxidation state? Is it > reliable, or should we use E₀ and compare it with references of well-known > oxidation states? > > > > Many people use pre-edge peaks of transition metals for reliable analysis > of metal oxidation states. > > > > E0 is sort of poorly defined term. For the transition metals, there will > usually be a sharp rise in mu(E) at the energy of the metal’s own 4p > electrons – the “main edge”, though this can sometimes be tricky to > identify precisely, and sometimes has structure (as TiO2 does – slightly > different for its different forms). > > > > >> In addition, TiS2, in which titanium is also in the 4+ oxidation state, > shows pre-edge peaks at 4968–4971 eV. (21) Considering the titanium > oxidation state > > >> in the raw materials, the stability of the titanium species, and the > XANES results, the oxidation state of the titanium species in LTS-213 is > likely to be 4+. > > > The second conclusion is even more unclear. > > What confuses me there is “TiS2 is in the 4+ *oxidation* state”. > Titanium disulfide is not oxidized at all - it is bound to sulfur. Its > charge state could be 4+, and many chemists use “oxidation” to mean the > transfer of charge to and from a metal, whether this is done by oxygen or > not. For XANES, the ligand species matters. K-edge XANES shows the > energies of the unfilled p states at the center of the Ti atom, which will > be very different for Ti-S (more covalent) and Ti-O (more ionic) bonds. > > --Matt > > > > > > *From: *Benito Melas via Ifeffit <ifeffit(a)millenia.cars.aps.anl.gov> > *Date: *Thursday, February 27, 2025 at 7:28 AM > *To: *ifeffit(a)millenia.cars.aps.anl.gov <ifeffit(a)millenia.cars.aps.anl.gov > > > *Cc: *Benito Melas <metal.cnea(a)gmail.com> > *Subject: *[Ifeffit] Question about Ti edge > > Hi all, I was following this article about Li2TiS3 https: //pubs. acs. > org/doi/full/10. 1021/acs. inorgchem. 4c03864 and found this Ti edge > XANES figure The authors claim The peak position for LTS-213 is > approximately 4970 eV, which agrees well with > > ZjQcmQRYFpfptBannerStart > > *This Message Is From an External Sender * > > This message came from outside your organization. > > ZjQcmQRYFpfptBannerEnd > > Hi all, > > I was following this article about Li2TiS3 > > > https://urldefense.us/v3/__https://pubs.acs.org/doi/full/10.1021/acs.inorgc… > <https://urldefense.us/v3/__https:/pubs.acs.org/doi/full/10.1021/acs.inorgch…> > > > and found this Ti edge XANES figure > > > The authors claim > > > > The peak position for LTS-213 is approximately 4970 eV, which agrees well > with that for rutile TiO2 with a valence of titanium species in the 4+ > oxidation state. > > > > Should we use the pre-edge to determine the oxidation state? Is it > reliable, or should we use E₀ and compare it with references of well-known > oxidation states? > > > > In addition, TiS2, in which titanium is also in the 4+ oxidation state, > shows pre-edge peaks at 4968–4971 eV. (21) Considering the titanium > oxidation state in the raw materials, the stability of the titanium > species, and the XANES results, the oxidation state of the titanium species > in LTS-213 is likely to be 4+. > > > > The second conclusion is even more unclear. > > Would you help me see if I am missing something in my understanding of > oxidation states using XANES? > > > > Best, B. > > > >

1 0

Diatomic distance on each EXAFS of both elements
by "Qiang Chang (常强)" 27 Feb '25

27 Feb '25

3 2

Re: Water-free binder advice
by Michele Piana 27 Feb '25

27 Feb '25

1 0

Not being able to generate FEFF paths from CIF
by cameron.mollazadeh＠colorado.edu 25 Feb '25

25 Feb '25

Hi! I have been trying to generate a FEFF path from a CIF I have however it hasn't worked. I tried pre-generating the inp file as well but it just stalls out and doesn't go anywhere. I have talked to some people In my lab who use the software as well and they also have encountered the same problems. It had worked once in the past for me but now is longer working. I have tried changing the unit cell and everything, however nothing is seeming to work. Best, Cameron

7 8

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

2 1

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]

1 0

Artemis: Rejects first shell fitting
by avijay＠ethz.ch 14 Feb '25

14 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

5 5

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

2 1

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

2 1

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

2 1

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

1 0