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

S XANES question
by Matthew Marcus 26 Nov '14

26 Nov '14

A user on ALS 10.3.2 is taking S K-edge XANES and consistently finding a strong peak at 2484eV (calibration: gypsum white line = 2482.75eV). There's a shoulder at the nominal position of the sulfate peak. Now, peaks below sulfate I can understand, but since there's no such thing as heptavalent sulfur, what could give a peak *above* the sulfate white line? Anybody ever seen that? Yes, we checked calibration. mam

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experimental standard
by Yun Xu 18 Nov '14

18 Nov '14

Hi all I have a complex oxide BaTi8-xGaxO16. What standards I should run? Ga is the dopant. I guess I should run the sample without dopant BaTi8O16 as standard, or the simple oxide as BaO, TiO2 Ga2O3? or is the standard necessary? Also, I have colleage working on DFT, I assume the theoretical standard is the result from the DFT calculation, and by using the coordinates of the atoms, I can run FEFF and fit the data. Thanks Yun

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installing Demeter on Yosemite
by Katherine M. Davis 12 Nov '14

12 Nov '14

Dear all, I was wondering whether anyone had tried installing the software on the new Mac OS (10.10 Yosemite)? Everything seems to work fine initially. I installed Macports and checked it installed correctly. At least when I test various commands, it seems to work. The sudo port install xorg-server demeter-devel command ran for about 3 hours until it quit. I tried restarting, but whenever I run the command, the following error message appears: ---> Computing dependencies for xorg-server ---> Cleaning xorg-server ---> Computing dependencies for demeter-devel ---> Configuring demeter-devel Error: org.macports.configure for port demeter-devel returned: configure failure: command execution failed Please see the log file for port demeter-devel for details: /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_science_demeter/demeter-devel/main.log To report a bug, follow the instructions in the guide: http://guide.macports.org/#project.tickets Error: Processing of port demeter-devel failed I will post the log file at the bottom of the email. The last 8 lines are as follows: portbuild::add_automatic_buildsystem_dependencies :debug:clean No need to upgrade! p5.16-term-twiddle 2.730.0_1 >= p5.16-term-twiddle 2.730.0_1 :debug:clean epoch: in tree: 0 installed: 0 :debug:clean p5.16-text-template 1.460.0_1 exists in the ports tree :debug:clean p5.16-text-template 1.460.0_1 is the latest installed :debug:clean p5.16-text-template 1.460.0_1 is active :debug:clean Merging existing variants '' int Would anyone be able to help me with this? Any advice would be useful. Thanks for your time. Best, Kate Davis

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Re: [Ifeffit] Fwd: Re: Re: problem about negative
by Bruce Ravel 12 Nov '14

12 Nov '14

On 11/11/2014 10:19 AM, Bruce Ravel wrote: > Rbkg>1.1 can avoid the first peak,but the remaining curve is somewhat > not smooth.How to distinguish whether a long wavelength oscillation > appear as a real peak or false one?I am confused about it. > I find when I avoid the first scattering peak after white > line(kmin=4.8 maybe too large),the first peak of R space > disappeared.Because usually the first scatering peak is related to the > first coordiantion shell,can I think the first peak in R space less 1A > is a real peak instead of noiseï¼ Zhanfei, As I said yesterday, I don't know anything about your sample, so it is hard for me to know what the "right" answer is to your problem. But I can make some observations and some suggestions. * Your data range is really short. As you seem to have noticed (judging from the very short k-range in your project file), your data has serious systematic problems starting at 9 or 10 inverse Angstroms. I cannot quite tell, but your data appear to be transmission data. Well it is possible that you have some instability or nonlinearity at the beamline, I would guess that your sample is not very homogeneous. It is possible that more disciplined sample preparation might help extend that range of the interpretable data. * You are right that slightly increasing the Rbkg value seems to make a positive difference in the extracted chi(k) data. Your data seem to be an example of the sort of data I was alluding to yesterday. The background subtraction is difficult because it is difficult to distinguish the Fourier components of the background function from the Fourier components of the data. I think that the background subtraction with Rbkg=1.1 looks much better than with Rbkg=1.0, but given how different they are, you have to be concerned about the correlations between the background and the parameters of the data. It is clear that your data are of the sort for which background subtraction is difficult. So how do you know what is an acceptable background subtraction? Well, using only Fourier methods, I think we have demonstrated that you cannot know the right answer without some kind of prior knowledge. So, how do you get that prior knowledge? Well, my advice is to first solve some simpler problems. Measure your standards. Measure the common forms of moly oxide and moly sulfide. Measure moly metal. Analyze all of them. The advantage of the standards is that you know what the answer should be. Do the data processing and data analysis. Make sure that, when you do the analysis, you get the right answers. Having done that exercise, you will then have a lot more knowledge about what the various forms of moly oxide look like and what the challenges are when doing the data processing and data analysis. Some questions: - Are there any forms of moly oxide for which the bond length is as short as 1.6? If so, do the conditions of formation exist in your system? Is your sample of a valence consistent with the valence of the Mo when it has such a short bond? - If you convince yourself that it is possible for moly to have an oxygen atom at 1.6 or 1.7, what did you have to do with your standard to get a sensible analysis of the EXAFS data? Hopefully, that will guide you to doing a sensible analysis of your unknown sample. - If none of your moly oxide standards have an O atom at 1.6 or 1.7, why do you think it is chemically reasonable for your unknown sample to have such a short bond? If, in fact, that short bond doesn't exist elsewhere in nature, why would your sample magically have such a short bond? - If you do not believe in such a short bond, then does your experience with the standards give you the confidence to increase Rbkg such that the low-R signal is removed by the background function? I completely understand that you have a compelling reason to understand your unknown sample and that I am suggesting that you spend a good chunk of time measuring and analyzing a bunch of standards that are not your actual research project. That might seem like time that takes you away from your real goal, but you have already demonstrated that you are stumped by your real goal. I am saying the only way to get over your current hurdle is to take a step back and gain a deeper understanding of the data, the physics of EXAFS, the methods of EXAFS analysis, and the intricacies of your current problem. B -- Bruce Ravel ------------------------------------ bravel(a)bnl.gov National Institute of Standards and Technology Synchrotron Science Group at NSLS --- Beamlines U7A, X24A, X23A2 Building 535A Upton NY, 11973 Homepage: http://bruceravel.github.io/home/ Software: https://github.com/bruceravel Demeter: http://bruceravel.github.io/demeter/

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too small bond length in R space
by ZHAN Fei 11 Nov '14

11 Nov '14

Dear all： I encounter a problem of exafs fit in an example of Mo which have Mo-O Mo-S Mo-Mo bond.The problem is that the Mo-O peak in R space has too small bond length (less than 1.4A(+0.5A for phase correction) ).Because when 1.2>rbkg>0.68 there is little change in spectrum of R and k space,and when I increase the value of rmin of forward Fourier transform the peak changes little,so I think it's not a noise.But when I try to fit it use the 1.35A path of Mo-O,I can't fit it well. Could you give me some advise about fit too small bond length,or recommend papers of similar situation? picture of R space is attached. Thanks Sincerely, zhanfei ihep of China

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Larch-0.9.24 with Python2
by Matthias Filez 05 Nov '14

05 Nov '14

Dear mailing list user, When running an example file of Larch-0.9.24 with Python2 on Ubuntu x86_64, the following error was reported. File "Py_usinglarch.py", line 32, in <module> autobk(xafsdat.energy, xafsdat.mu, rbkg=1.0, _larch=my_larch) File "/usr/local/lib/python2.7/dist-packages/larch/__init__.py", line 37, in wrapper return fcn(*args, **keywords) File "/usr/share/larch/plugins/xafs/autobk.py", line 187, in autobk fit.leastsq() File "/usr/local/lib/python2.7/dist-packages/larch/fitting/minimizer.py", line 395, in leastsq lsout = leastsq(self.__residual, self.vars, **lskws) File "/usr/local/lib/python2.7/dist-packages/larch/fitting/minimizer.py", line 222, in leastsq shape, dtype = _check_func('leastsq', 'func', func, x0, args, n) ValueError: need more than 1 value to unpack Is Larch-0.9.24 compatible with Python2 on Ubuntu x86_64? If not, what packages and dependencies could we install to make it work on Python2? Or is Larch-0.9.24 only compatible with Python3? Many thanks in advance, Matthias

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Reporting the fitting data (uncertainty associated with N)
by pushkar shejwalkar 05 Nov '14

05 Nov '14

Dear All, I have seen and also been told by few professors that when you report the fitting you must report the uncertainty associated with the measurement as evaluated by the program used for the fitting. Now, When I do the fitting I typically get the +/- values for E0, delR, ss and SO2. However, the N value we always put either 1,2 or such whole integers. Is there any way to find out the uncertainty associated with the coordination number (N used in XAFS equation)? If so how to find such uncertainty? can we see this in the log file generated after the fitting is over? Thank you very much for the help Best Regards, Pushkar Shejwalkar. Post-doctoral -Researcher,JSPS Fellow Hokkaido University, Sapporo, Japan

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Structure of Au2O3
by kaziz sameh 04 Nov '14

04 Nov '14

Hi all, I need the structure of Au2O3. if you can help me I would be very grateful. Kaziz

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Re: [Ifeffit] inp file - artemis crashing when running feff calc on manually generated inp file
by stephen.parry＠diamond.ac.uk 03 Nov '14

03 Nov '14

The dartemis output log file -- This e-mail and any attachments may contain confidential, copyright and or privileged material, and are for the use of the intended addressee only. If you are not the intended addressee or an authorised recipient of the addressee please notify us of receipt by returning the e-mail and do not use, copy, retain, distribute or disclose the information in or attached to the e-mail. Any opinions expressed within this e-mail are those of the individual and not necessarily of Diamond Light Source Ltd. Diamond Light Source Ltd. cannot guarantee that this e-mail or any attachments are free from viruses and we cannot accept liability for any damage which you may sustain as a result of software viruses which may be transmitted in or with the message. Diamond Light Source Limited (company no. 4375679). Registered in England and Wales with its registered office at Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom

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inp file - artemis crashing when running feff calc on manually generated inp file
by stephen.parry＠diamond.ac.uk 03 Nov '14

03 Nov '14

Can someone spot the problem with the attached inp file? I have manually reduced a cif file to remove multiple occupancy sites and cut down the unit cell from a large structure. I should be left with the first shell as Cartesian co-ords. I have then overwritten the co-ords and ipots into an old atoms generated inp file. I can't spot any formatting problems but when I run the feff calculation in artemis the program crashes. The feff.run error log file contains nothing obvious. "Feff 6L.02 TITLE Ga_c6h5f TITLE Ga TITLE S TITLE Gallium TITLE Note: mixed occ removed manually SP Calculating potentials and phases... free atom potential and density for atom type 0 free atom potential and density for atom type 1 free atom potential and density for atom type 2 overlapped potential and density for unique potential 0 overlapped potential and density for unique potential 1 overlapped potential and density for unique potential 2 muffin tin radii and interstitial parameters " Any help appreciated. Regards, Steve ================= Dr Stephen Parry Support Scientist, B18 Diamond Light Source Ltd. -- This e-mail and any attachments may contain confidential, copyright and or privileged material, and are for the use of the intended addressee only. If you are not the intended addressee or an authorised recipient of the addressee please notify us of receipt by returning the e-mail and do not use, copy, retain, distribute or disclose the information in or attached to the e-mail. Any opinions expressed within this e-mail are those of the individual and not necessarily of Diamond Light Source Ltd. Diamond Light Source Ltd. cannot guarantee that this e-mail or any attachments are free from viruses and we cannot accept liability for any damage which you may sustain as a result of software viruses which may be transmitted in or with the message. Diamond Light Source Limited (company no. 4375679). Registered in England and Wales with its registered office at Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom

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Mac support for Demeter
by Bruce Ravel 28 Oct '14

28 Oct '14

Hi gang, I just heard from Frank Schima, the fellow who kindly provided packaging of Demeter via MacPorts. Frank is moving to a new position at NIST Boulder and will no longer be providing IT support for the group out there that does some XAS. That means his availability to maintain and update the MacPorts package will be somewhere between slim and non-existent. Here is what he said: I am no longer working for Quantum Devices as of Friday, 10/31/2014. So I will no longer be involved in updating Demeter and will be unsubscribing from the Ifeffit mailing list. For updates please follow the Macports procedures to request an update in Macports by opening a Trac ticket [1]. I may actually be able to perform the update but I cannot guarantee anything. [1] <https://trac.macports.org/newticket> I know that this support for the Mac was valued by many people in our community, so Frank will be missed. I am not able to provide packaging support for Mac users. Even if I had the time or energy to take on a new packaging responsibility, I simply don't own a Mac. This would be a good time for someone to step up and take over responsibility for the Mac package. It seems that Frank has done the bulk of the work. The MacPort ecosystem seems to be well supported and well documented, so I would think that someone else could readily step into that role. B -- Bruce Ravel ------------------------------------ bravel(a)bnl.gov National Institute of Standards and Technology Synchrotron Science Group at NSLS-II Building 535A Upton NY, 11973 Homepage: http://bruceravel.github.io/home/ Software: https://github.com/bruceravel Demeter: http://bruceravel.github.io/demeter/

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errors importing Artemis project with quick first shell paths
by Bruce Ravel 28 Oct '14

28 Oct '14

Ian, I am starting a new thread for your email. It is only peripherally related to the problem discussed in the other thread. The main problem was two mistakes in how a quick first shell path was brought back to life when importing the project file. I'll explain, although one of the problems is rather technical. Mistake #1 is related to the option for auto-generating variables. That flag was not turned off, so the auto-generated parameters got regenerated, over writing the ones you chose. Yikes! Mistake #2 involved an assumption about the order of entries in a hash data structure while bringing the QFS path back to life. That is extremely sloppy on my part because the order of hash entries is not predictable. This was leading to the intermittent aspects of the behavior. > Dear All, > Sorry for resurrecting this old thread but I've been experiencing a > bug that produces very similar symptoms and that I guess may be > related; but that won't be solved by Bruce's fix. Details are as > follows: > Software: Demeter 0.9.18.2 and 0.9.20 x64 (possibly earlier releases > too) on Windows 8.1 x64 (I've never observed this bug on Windows > versions before 8, but I've been using Windows 8 as my main OS for a > while now so that may be coincidental) > Steps to reproduce: I run a fitting project using quick first shell > fits and save it. When I re-open the project around 80% of the time > the problem occurs. > Symptoms: When I re-open the project around 80-90% of the time one or > more of the following occurs: > - One of the quick shell paths completely loses all its information > (including path information which isn't editable by the user, > parameter info etc; see attached screenshot) I believe that I have fixed this. > - Parameter info for one or more paths is reset to the default > (i.e. if I've named a path delrauau it's renamed dr_ag_au_1) Again, I believe that I have fixed this. > - In the GDS window starting values for parameters that have a > non-zero starting value are set to their previously guessed value, > rather than the starting value I set (ie. If I set ss as 0.003 and > during the fit it is guessed to be 0.001 when I reopen the project > the starting value will be set to 0.001) and "restrain" parameters > are changed to "guess". I have examined the history of your project. At no point is a fit saved with a restraint. The GDS windows is filled correctly according to the contents of your project file. Also, the initial guesses are all entered into the GDS window with the values I see in the history. Are you saying that you have made a restraint, saved the project, then had Artemis fail to remember that you had made a restraint? > - Phase correct fitting boxes are unticked (sometimes in an > "impossible fashion" where the "plot with phase correction" option > is set but no paths have the "use path for phase corrected plotting" > option set) I don't understand how that can be a problem. The default is not to plot with phase correction. I don't save the state of that button in the project file in any case. I need to do a bit more testing, hopefully I'll make a new trial release package for your to test before the end of the day. B > Attachments: > Noinfo.png - screenshot of Artemis when path info is lost > Reset.png - screenshot of Artemis when parameter names are reset > Dartemis.log - Artemis log file when opening a project that has this problem > Artemis.fpj - Artemis project file that displays these symptoms. > Please let me know if you need further info/files. > Thanks, > Ian > Ps: > OK, things got weird while preparing this bug report: The file in > question stopped opening at all - Artemis loaded and went through > loading fit x, x+1 etc., once it finished (not exactly sure what > stage) it just closed. And then, after several attempts, started > working again, as if by magic, before I'd saved a log file.... If I > can figure out how to reproduce this I'll send more info... -- Bruce Ravel ------------------------------------ bravel(a)bnl.gov National Institute of Standards and Technology Synchrotron Science Group at NSLS-II Building 535A Upton NY, 11973 Homepage: http://bruceravel.github.io/home/ Software: https://github.com/bruceravel Demeter: http://bruceravel.github.io/demeter/

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Saving data as chi(E) from Athena?
by Karina Mathisen 28 Oct '14

28 Oct '14

To whom it might concern The older version of Athena had the possibility to save the data as chi(E), which is sorely missed in the newer version. Is there an easy fix for this? Best regards Karina Mathisen ------------------------------------------------------------------------------- Karina Mathisen, PhD Deputy Head for teaching, Department of Chemistry NTNU - Norwegian University of Science and Technology Associate professor Karina.Mathisen(a)ntnu.no<mailto:Karina.Mathisen@ntnu.no> +47 735 96218 Realfagbygget E2-106, Høgskoleringen 5, Trondheim, Norway --------------------------------------------------------------------------------

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Question about using a proper model
by pushkar shejwalkar 28 Oct '14

28 Oct '14

Dear All, I am new to XAFS data analysis and have very limited knowledge about using modelling structures for XAS analysis. I am not sure as to if this question is directly related to Demter or XAFS analysis as such but its a part of it for sure. * Question number one* I am trying to analyze the sample I recently collected at SPring-8 facility. The structure I am hoping to be formed during the reaction is more of a organometallic complex at silica interface. In order to establish the structure I was told that there are two methods I could use. 1) Use a counter part compound which is exact/looks like the structure I am hoping (so basically known compound) and then do traditional comparison method to establish the structure. UNFORTUNATELY I cannot synthesize such compound in lab nor such material is available in literature ( including crystal structure). 2) is to use the model. right now for modelling such structure I am using Spartan program (again I have not used it earlier in my graduate work) So I want to know as to how to generate the models in order to get the correct crystal parameters? (atoms positions?) Is spartan good enough to do job? is there any other method for doing such fitting? * Question number two* In order to get lower E0 values after the fitting, I read that there is a method to use in which delE value can be set to 0 intentionally and then recalibrating the spectra in athena again in order to accurately calibrate the E0. I read paper by Shelly kelly and Bruce Ravel. Also I have seen the steps in one of shelly kellys PDF formatted lecture, although I am still not sure about the exacts steps to take in order to do such calibration. Could someone explain me the steps in details (especially taking artemis files to athena and then using it as STD spectra for calibration purposes, I am confused about that) Thank you very much everyone in advance for your patience to go through such a long email and helping to solve my silly doubts. Your New Bee in this fantastic group Pushkar

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Setting E0 for imported data
by Scott Bechler 27 Oct '14

27 Oct '14

Hello, I am trying to compare a sample with unknown lead bonding with some lead standards. After entering in all of the data and standard scans with reference channels, I aligned the reference channels, which shifted the data scans as well. My question regards the E0 of the data and standard scans. Even though the scan itself shifted, the E0 still remains where it was when I imported it, prior to aligning the reference channels. The peak itself shifted, but the program still marks the E0 at the previous peak position. Is this an issue? If so, how do I adjust the E0 of the scans the same amount that the reference channels shifted? It does say how much the scan shifted, so I went in and manually changed the E0 of each scan so that it correlated with this shift. Would this be an effective solution? If this does solve my problem, is there a less labor-intensive way to solve it in the program? Thanks so much for your help! -Scott

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save Artemis project and cannot find Path List information when reopen
by huyanyun＠physics.utoronto.ca 26 Oct '14

26 Oct '14

Hi all, I encountered a serious problem with saving an Artermis project on my windows 8 64bit desktop. When I am ready to finish my fitting work, I click to save the log file, and go to main window to choose -File-'save project as...', and then close Artemis. But when I reopen this saved project, the Path Page lost all information for each path, and the 'Include path' button has been surprisingly unchecked for all path. The GDS page have all information there. This happened to me several times, but it seems sometime the PathPage data is saved and sometime is not, although I think I was doing the exact something. I attached one of my artemis project file and the most recent log file I saved before I close the program. Can anyone have a look and tell me what I did wrong? As my work is proceeding, this would be a very serious problem if I cannot save my 'hardwork'. Best, Yanyun ----- Attachments (links will expire on 28/02/15): 1. CoedgeforGa0.15 fitting.fpj (7.7 MB) [application/zip] Download link: https://webmail.physics.utoronto.ca/imp/attachment.php?id=53ffbffa-2424-413…

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simulating As K edge XANES using full multi scatering method
by Shaofeng Wang 24 Oct '14

24 Oct '14

Dear all, Does anyone have experience for simulating As K edge XANES using multi-scatering method or some other methods. Please introduce some papers or articles to me. Any help is appreciated. Regards, Shaofeng

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Artemis closes when I try to open a project file or import data
by Kurinji Krishnamoorthy 22 Oct '14

22 Oct '14

Hi, Artemis had been working well on my laptop for a while. But today when I attempted to open a saved project file ( with a *.fpj extension), the program tried to open it for a while but then ultimately closed without any error messages. A similar thing occurred when I tried to import an Athena data file into Artemis. I was wondering if anybody had any idea how to fix this problem? Thanks, Kurinji

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Athena does not React after 2-4 steps
by Michael Kömm 22 Oct '14

22 Oct '14

Dear Bruce and dear mailing list, Athena stops working after doing a maximum of four steps (f.e. removing points, import data,...) when running on my PC with Windows 8. It either says "not responding" or just shuts down. Whenever Athena shuts down the errors in the .txt in the directory of the project differs. But it always looks like this: line 0: warning: Skipping unreadable file "C:\Users\Michael\AppData\Roaming\demeter\stash\gp_leqfnhqh" line 0: No data in plot only the file name changes. But there's never a file with that name in that directory. Sometimes there is as well a window opened that says: gnuplot.exe is not working anymore. I've deleted the Roaming\demeter folder but it didn't end the troubles. Hope there is a way to end this problem. Sincerely yours Michael Koemm PS: There is also one of my projects in the attachment.

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multiple absorber atoms
by Jesús Eduardo Vega Castillo 21 Oct '14

21 Oct '14

Hello, This is my first message to the list so I expect to do it right. I need to generate a path list for EXAFS fitting within ifeffit, based on a crystalline structure that has two different crystallographic positions for the absorber atom (edge K of Mo). Is there any way to do this? I would appreciate any information you could give me. Thanks in advance Jesus

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Importing data to Athena
by Samson Vallerie Ann 20 Oct '14

20 Oct '14

Hi Bruce, I have some trouble importing data to Athena even if it's just ordinary column text file. I have attached two sample data. These are processed data from full-field XANES images. Basically I select a region in the image then write/output the total intensity of that region in a text file and I just iterate over several images. I have tried deleting out the headers, putting back the headers, padding some 0's in the energy column, checking some plugins, but to no avail. Your tips, advice is badly needed. Many thanks, Vallerie

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"PCA not enabled" on Mac version of Demeter: Athena
by Ellen Daugherty 16 Oct '14

16 Oct '14

Hello XAFS community, I recently upgraded to the new version of Demeter (0.9.20) for Mac and am trying to run principal components analysis on my spectra. When I click on "Principle components analysis" from the main menu, the window shows the following message: "PCA is not enabled on this computer. The most likely reason is that the perl modules PDL and/or PDL::Stats are not available." Perhaps the solution here is simple, but I am not familiar with perl modules and do not understand the source of the issue. I could not find information about this problem in the Mail Archive, though I may have missed something. Do I need to download the PDL perl modules separately from the Demeter installation? Could there be files that are not located in the proper directory? Or perhaps PCA is simply not available for Macs? Please let me know if further information would help in solving this problem. Thank you! Ellen -- Graduate Student Research Assistant Department of Chemistry Colorado State University

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XAFS Analysis using Ifeffit
by Ke Yuan 16 Oct '14

16 Oct '14

Hello Drew, Thanks for your suggestions. I just checked my original data without normalization. The edge step is about 0.7 (see pic attached). I did the measurement in fluorescence mode at APS, beamline 12-BMB. What do you think about this pic? For the sample preparation, I think I need to mix UO2 with some other materials to dilute it. Do you have any suggestions on the matrix materials? Best, Ke

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(no subject)
by Ke Yuan 16 Oct '14

16 Oct '14

Hello Pushkar, I think the peak value of the first derivative and the zero value of the second derivative does the same thing. My sec deriv is very noisy so it's easy for my to pick the peak value of the 1st deriv instead. I would suggest you to watch the video from Bruce which explained HOW TO PICK Rbkg at: http://www.diamond.ac.uk/Beamlines/Spectroscopy/Techniques/XAS.html Click the Athena: Data processing II Actually all the other video lectures are very helpful, too! Best, Ke

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iXAFS & xQuartz
by Gaspard Jean-Pierre 16 Oct '14

16 Oct '14

Hi all, On a MacBook under OS X.8.5, I downloaded iXAFS and xQuartz. I start xQuartz. When I try to start iXAFS, it requests X11 that is obviously active, I see it. However iXAFS says : "X11 is not installed". I am missing something but I do not know what. Regards JP

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