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

Re: [Ifeffit] Contents of Ifeffit digest...
by charvi singhvi 07 Oct '23

07 Oct '23

Dear Team, I want to subscribe to the Ifeffit mailing list. I am very new to XAS analysis and I aim to gain expertise in it. I have visited ESRF beamline recently and have promising data. I need to do a proper analysis in order to extract useful information. Your help through this mailing list is much appreciated. Kind Regards Charvi Charvi Singhvi c/o Prof. Vivek Polshettiwar Graduate Student Department of Chemical Sciences (DCS), Tata Institute of Fundamental Research (TIFR), Homi Bhabha Road, Colaba, Mumbai 400005 India Phone: +91-22-2278 2986/2051 Email: charvi.singhvi(a)tifr.res.in Home page: https://www.nanocat.co.in/ https://www.tifr.res.in/~dcs

1 0

Fitting mechanism of Artemis
by bikov＠phys.uni-sofia.bg 06 Oct '23

06 Oct '23

Dear all, I have a general question regarding the mechanism employed in the fitting procedures implemented in Artemis. How exactly is performed a fit? Do we have a fixed central atom (absorbing/emitting atom) and only the distances to the neighbors included in the probed pathways are varied, i.e. by varying the coordinates of the corresponding neighbor atoms, or during the fitting process Artemis can vary the position of the absorption center too? Could the procedure be constrained in such a way that the scattering pathways are adjusted by only varying the coordinates of the central atom? With kind regards, Konstantin Bikov PhD Student at the Physics Department of the University of Sofia, Bulgaria

3 2

Larch 0.9.72
by Matt Newville 03 Oct '23

03 Oct '23

Hi Folks, It's been a few months since the last release, but Larch 0.9.72 is now available. There have been several fixes and a few new features. The XAS analysis GUI application has been renamed from the rather dull name of "XAS Viewer" to "Larix" (the genus of trees for the Larch family). We (well, mostly Mauro Rovezzi and others at ESRF) put in a lot of effort over the summer to generate FDMNES inputs from structural information (CIF files, structural information from the Materials Project). This effort to convert structure information to input files for Feff, FDMNES, etc. has been evolving over the past several months, and there will probably be more done on this in the coming months. If you are interested in getting involved, let us know. There are new binary installer scripts for Windows, MacOS, and even Linux, and the "GetLarch" scripts have been updated too. These all will now install a Python 3.11 environment. Although installation is not fast, it is somewhat faster than it has been in the past due to using the Mamba variation of the Anaconda Python tools. More release notes are at https://github.com/xraypy/xraylarch/releases/tag/0.9.72 If you have a fairly recent version of Larch installed, you should be informed that a new version is available, and be prompted to install or run the Larch Updater script. Let us know if you have any troubles with this version or questions, comments, or suggestions for improvements! --Matt

1 0

TiOx K-edge spectra
by Rebecca Katharina Pittkowski 20 Sep '23

20 Sep '23

Dear community, I am preparing a teaching exercise for a course on nano-structure characterization, and I was hoping that someone has some K-edge spectra of titanium oxide nanoparticles lying around that I could reuse for the course. I have been through the NIMS Material Data Repository and found some useful references but it would be great to have a nano-sized example as well. That could very well be from a published article, which I could include in the teaching. Thanks for any input. Greetings from Copenhagen, Rebecca Rebecca K. Pittkowski Tenure-track Assistant Professor University of Copenhagen Center for High Entropy Alloy Catalysis Department of Chemistry Universitetsparken 5 2100 Copenhagen Ø DENMARK Rebecca.pittkowski(a)chem.ku.dk [/var/folders/gc/lhyz4xy96q77x4sbrrh4l46r0000gn/T/com.microsoft.Outlook/WebArchiveCopyPasteTempFiles/cidimage009.png(a)01D5C49F.F68E4220]

1 0

P K-edge EXAFS
by Marcelo Eduardo Alves 15 Sep '23

15 Sep '23

Hi there, I begin by examining phosphorus adsorption by goethite, hematite, and gibbsite. Why is it difficult, if not impossible, to obtain EXAFS spectra at the P-K edge that can be properly used, i.e., spectra with a high signal-to-noise ratio, especially for dilute samples? Would it be possible to use arsenic as a phosphorus proxy to get conclusions from As K-edge EXAFS data that could be extended to P? Thank you.

5 6

EXAFS-50 symposium and short course, Oct. 30-Nov. 3 at BNL
by Anatoly Frenkel 08 Sep '23

08 Sep '23

Dear subscribers: Sharing here my Linkedin post: I am excited to share that Brookhaven National Laboratory will be hosting the Symposium ("EXAFS-50") that will mark the 50th anniversary of Stern-Sayers-Lytle team's introduction of the Extended X-ray Absorption Fine Structure (EXAFS) technique in early 1970s. The Symposium will open the week of events, hosted by Brookhaven National Laboratory, that will include the talks of the experts in the field on the past, present and future of the EXAFS technique on Oct. 30 and 31, and culminate by the three-day long short course on advanced data analysis methods of EXAFS, from Nov. 1 to 3. Both events will be in-person. The web sites below have all the information for registration for the symposium (registration begins on Aug. 21) and for application/registration for the short course (application deadline is Aug. 31). Although the Symposium and the Short course are organized and run as separate events, attending both of them will be ideal for graduate students and postdocs. No registration fee is charged for attending these events but registration is required. EXAFS-50: https://www.bnl.gov/exafs-50/ XAFS short course: https://www.bnl.gov/xafscourse/ ------------------------------------------------------------------- Anatoly I. Frenkel Professor Department of Materials Science and Chemical Engineering (primary appointment) Department of Chemistry (affiliate appointment) * Stony Brook University * Stony Brook, NY 11794 Email: anatoly.frenkel(a)stonybrook.edu <https://mail.bnl.gov/OWA/redir.aspx?C=F6wCGt4adziN6IvpdRQ-rWdgy3Oaoif_x-0yb…> http://you.stonybrook.edu/frenkel Co-Director and Spokesperson, Synchrotron Catalysis Consortium (SCC) at BNL http://you.stonybrook.edu/scc2 Joint Appointment: Senior Chemist Chemistry Division, *Brookhaven National Laboratory* Upton, NY 11973. Ph: 631-344-3013. Group: 631-344-3494 Email: frenkel(a)bnl.gov https://www.bnl.gov/staff/frenkel -------------------------------------------------------------------

1 1

CatMASS - XAS "Catalyst" Sample Mass Calculator
by Hoffman, Adam S 07 Sep '23

07 Sep '23

Hi All, We would like to announce the release of CatMASS - a XAS (and X-ray scattering) sample mass calculator for complex sample compositions most commonly found in catalysis science. This software builds off of codes found in Hephaestus and XAFSMass allowing for more complex sample descriptors (multiple metals/supported organometallics) and allows for the inclusion of diluents. The absorption can be visualized in E- or k-space highlighting potentially competing edges in the sample that may limit the range of your EXAFS data collection. The documentation can be found in the recent publication: https://onlinelibrary.wiley.com/iucr/doi/10.1107/S160057752300615X To download the executable file (windows only) please see the link here: https://web.slac.stanford.edu/coaccess/resources/software To download the python-based version or collaborate on the GitHub project please go to: https://github.com/ahoffm02/catMass If you have any questions please reach out to Jorge Perez-Aguilar (jperezag(a)slac.stanford.edu<mailto:jperezag@slac.stanford.edu>) or myself, Adam Hoffman (ashoff(a)slac.stanford.edu<mailto:ashoff@slac.stanford.edu>). Cheers, Adam Hoffman, Jorge Perez-Aguilar, and the Co-ACCESS team

1 0

Shift in Eo when fitting PtO2 and similar samples
by Zi Qi Chen 07 Sep '23

07 Sep '23

Dear all, I am looking at EXAFS of PtO2 powders and Pt particles supported on TiO2. I used a beta-PtO2 crystal structure data for the PtO2 EXAFS and after the first shell fit, I observed a large shift in Eo (delta Eo of ~14 eV) in my fit parameters. When I tried to fit the Pt foil to obtain the So2, the energy shift also seemed high (delta Eo of ~7 eV). I am wondering if there could be a problem in the selection of Eo prior to EXAFS analysis? I left the Eo as the energy at the first peak of first derivative (ifeffit default). All of the data were also aligned using the reference foil in Athena before looking at EXAFS. I am wondering what would have caused this shift? Any help is appreciated, thank you. Best regards, Yanny

5 4

Shift in Eo when fitting PtO2 and similar samples
by Clément Laskar 23 Aug '23

23 Aug '23

Dear Yanny Chen, You can find recorded and fitted EXAFS and HR-EXAFS spectra of PtO2 in our following paper: Laskar, C., Bazarkina, E. F., Kokh, M. A., Hazemann, J. L., Foulon, S., Leynaud, O., ... & Pokrovski, G. S. (2022). Exploring Platinum Speciation with X-ray Absorption Spectroscopy under High-Energy Resolution Fluorescence Detection Mode. *Minerals*, *12*(12), 1602. The spectra can be directly downloaded at the following link on the sshade database: https://www.sshade.eu/data/experiment/EXPERIMENT_GP_20181107_001 https://www.sshade.eu/data/experiment/EXPERIMENT_CL_20210211_001 Maybe it could help you to deal with your fitting problem to compare your spectra and your fit with ours, Regards, Clément LASKAR -------------------------------------------------------- Dear all, I am looking at EXAFS of PtO2 powders and Pt particles supported on TiO2. I used a beta-PtO2 crystal structure data for the PtO2 EXAFS and after the first shell fit, I observed a large shift in Eo (delta Eo of ~14 eV) in my fit parameters. When I tried to fit the Pt foil to obtain the So2, the energy shift also seemed high (delta Eo of ~7 eV). I am wondering if there could be a problem in the selection of Eo prior to EXAFS analysis? I left the Eo as the energy at the first peak of first derivative (ifeffit default). All of the data were also aligned using the reference foil in Athena before looking at EXAFS. I am wondering what would have caused this shift? Any help is appreciated, thank you. Best regards, Yanny

1 0

Postdoc position in XAS and catalysis is open at BNL
by Stavitski, Eli 21 Aug '23

21 Aug '23

Postdoctoral Research Associate Catalysis and X-ray Spectroscopy https://jobs.bnl.gov/job/upton/postdoctoral-research-associate-catalysis-an… Postdoctoral Research Associate Catalysis and X-ray Spectroscopy Description at Brookhaven National Laboratory<https://jobs.bnl.gov/job/upton/postdoctoral-research-associate-catalysis-an…> Learn more about applying for Postdoctoral Research Associate Catalysis and X-ray Spectroscopy at Brookhaven National Laboratory jobs.bnl.gov Job ID 3913Date posted 08/11/2023 Brookhaven National Laboratory (www.bnl.gov) delivers discovery science and transformative technology to power and secure the nation’s future. Brookhaven Lab is a multidisciplinary laboratory with seven Nobel Prize-winning discoveries, 37 R&D 100 Awards, and more than 70 years of pioneering research. The Lab is primarily supported by the U.S. Department of Energy’s (DOE) Office of Science. Brookhaven Science Associates (BSA) operates and manages the Laboratory for DOE. BSA is a partnership between Battelle and The Research Foundation for the State University of New York on behalf of Stony Brook University. Organizational Overview The Hard X-ray Scattering & Spectroscopy (HXSS) program at BNL’s National Synchrotron Light Source II (NSLS-II) offers world-class capabilities for studying complex and heterogeneous materials under in situ and operando conditions. The program provides advanced spectroscopy, diffraction, and imaging x-ray tools, supported by computational resources for high-throughput analysis and modeling. One of the leading research directions in the HXSS science program is heterogeneous catalysis with emphasis on in situ and operando characterization. The Inner Shell Spectroscopy (ISS) beamline is a frontier X-ray spectroscopy instrument allowing high throughput and high energy resolution studies of a variety of catalysts. ISS is aimed at establishing structure-function relationships under relevant reaction conditions. Position Description NSLS-II is seeking exceptional candidates for a research associate position in the Hard X-ray Scattering and Spectroscopy program. The successful candidate will work collaboratively with the ISS team and supporting technical, engineering and controls staff. They will be involved in developing, commissioning, and testing custom sample environments for catalysis experiments, including high pressure gas and integration of the high energy resolution spectrometers in the ISS operando catalysis research infrastructure. They will also be involved in the support of the users at the beamline, including industrial partners. Leveraging the technical developments, the successful candidate will conduct mechanistic studies of catalytic carbon dioxide hydrogenation at high pressures in collaboration with ISS scientists. Essential Duties and Responsibilities: * Develop, commission, and test new catalysis infrastructure at the ISS beamline. * Take part in the logistic work required for successful beamline user operation * Participate in experiment planning, execution, translation of results into new scientific knowledge. * Disseminate scientific results as manuscripts, conference presentations, progress reports etc. * Develop and maintain safe practices and working conditions. Position Requirements * A PhD in chemistry, chemical engineering, or materials science * Understanding of heterogeneous catalytic reaction mechanisms, demonstrated by a publication record * Knowledge of in-situ/operando characterization applied to heterogeneous catalysis, relevant instrumentation and data analysis methods * Experience with synchrotron X-ray characterization techniques * Excellent written and oral communication and presentation skills * Demonstrated organizational and planning skills and methodical record-keeping * Ability to work in a collaborative team environment Preferred Knowledge, Skills, and Abilities: * Demonstrated record of applying X-ray absorption spectroscopy to solve problems in heterogenous catalysis * Knowledge of X-ray absorption spectroscopy data modelling including advanced quantum methods * Expertise with sample environment development and applications * Proficiency in programming using Python or equivalent languages OTHER INFORMATION: * BNL policy requires that after obtaining their PhD, eligible candidates for research associate appointments may not exceed a combined total of 5 years of relevant work experience as a post-doc and/or in an R&D position, excluding time associated with family planning, military service, illness or other life-changing events. At Brookhaven National Laboratory we believe that a comprehensive employee benefits program is an important and meaningful part of the compensation employees receive. Our benefits program includes, but is not limited to: * Medical, Dental, and Vision Care Plans * Flexible Spending Accounts * Paid Time-off and Leave Programs (vacation, holidays, sick leave, paid parental leave) * 401(k) Plan * Flexible Work Arrangements * Tuition Assistance, Training and Professional Development Programs * Employee Fitness/Wellness & Recreation: Gym/Basketball Courts, Weight Room, Fitness Classes, Indoor Pool, Tennis Courts, Sports Clubs/Activities (Basketball, Table Tennis Pong, Softball, Tennis) Brookhaven National Laboratory and the Energy and Photon Sciences Directorate are committed to your success. We offer a supportive work environment and the resources necessary for you to succeed. Brookhaven National Laboratory (BNL) is an equal opportunity employer that values inclusion and diversity at our Lab. We are committed to ensuring that all qualified applicants receive consideration for employment and will not be discriminated against on the basis of race, color, religion, sex, sexual orientation, gender identity, national origin, age, status as a veteran, disability or any other federal, state or local protected class. BNL takes affirmative action in support of its policy and to advance in employment individuals who are minorities, women, protected veterans, and individuals with disabilities. We ensure that individuals with disabilities are provided reasonable accommodation to participate in the job application or interview process, to perform essential job functions, and to receive other benefits and privileges of employment. Please contact us to request accommodation. *VEVRAA Federal Contractor Brookhaven employees are subject to restrictions related to participation in Foreign Government Talent Recruitment Programs, as defined and detailed in United States Department of Energy Order 486.1A. You will be asked to disclose any such participation at the time of hire for review by Brookhaven. The full text of the Order may be found at: https://www.directives.doe.gov/directives-documents/400-series/0486.1-BOrde…<https://www.directives.doe.gov/directives-documents/400-series/0486.1-BOrde…> [cid:7661b08b-12f2-48e3-8920-20aae481d8b3] Eli Stavitski Sr. Scientist Inner Shell Spectroscopy (ISS) Lead Beamline Scientist. Phone: 631-344-8641 Email: istavitski(a)bnl.gov<mailto:istavitski@bnl.gov> National Synchrotron Light Source-II Bldg. 743, Brookhaven National Laboratory Upton, NY 11973-5000 [NSLS-II ISS]<https://www.bnl.gov/nsls2/beamlines/beamline.php?r=8-ID>[Title: LinkedIn - Description: image of LinkedIn icon]<https://www.linkedin.com/in/eli-stavitski-a033a713/>[Google, scholar Icon in SuperTiny]<https://scholar.google.com/citations?user=cVxErOsAAAAJ&hl=en>

1 0