Re: [Ifeffit] Normalization of LCF coefficients when fitting experimental spectra with theoretical spectra

2021-03-10 Thread Mike Massey
Hi Patricia, When you say "worse than the initial one," what do you mean? If it's a "worse" match than nonsensical fit results, but makes some physical and chemical sense, I'd personally argue it's a much better fit ;) What you are doing seems reasonable to me, but I would further recommend

[Ifeffit] Wyartite XAS spectrum?

2020-10-16 Thread Mike Massey
Hi All, And now for something not-phosphorus... Does anyone happen to have a wyartite U L3-edge XAS spectrum laying around? If you do, and happened to be willing to talk with me about it, I would be most grateful. Kind Regards, Mike ___ Ifeffit

Re: [Ifeffit] P K-edge XANES spectrum question (Mangold, Stefan (IPS))

2020-10-16 Thread Mike Massey
Yes I was wondering about this as well. Technically P(III) exists, and maybe one could find it in an AMBR? But I don't think anyone has a clue about what the K-edge XANES spectrum looks like. Has anyone ever collected a phosphite spectrum? That would be pretty cool. I would totally do it but

Re: [Ifeffit] Ifeffit Digest, Vol 212, Issue 7

2020-10-16 Thread Mike Massey
essage with subject or body 'help' to >ifeffit-requ...@millenia.cars.aps.anl.gov > > You can reach the person managing the list at >ifeffit-ow...@millenia.cars.aps.anl.gov > > When replying, please edit your Subject line so it is more specific than "Re: >

Re: [Ifeffit] P K-edge XANES spectrum question

2020-10-16 Thread Mike Massey
I recommend diluting this sample by a lot (20x maybe, or more) and collecting another spectrum. I've had instances of strange features in P spectra that ended up being weird self-absorption type artifacts. I will dig through the spectra I have from similar samples, this one reminds me of a

Re: [Ifeffit] Requesting guidance in understanding results from Athena

2020-09-13 Thread Mike Massey
It sounds to me like you are understanding things well. The short, short version is that the purpose of the rbkg parameter is to filter out the low-frequency oscillations (arising from any of numerous sources) in the spectrum, that correspond to interatomic distances that make no physical

Re: [Ifeffit] Reported W L3-edge and L2-edge energy

2020-05-07 Thread Mike Massey
; sharp peaks in CO2 gas at 292.74 and 294.96eV. >mam > >> On 5/7/2020 3:09 PM, Mike Massey wrote: >> Hi Matt, >> Indeed, in my experience (which is limited to one beamline at one >> synchrotron facility for P XAS), once it is calibrated, the energy selection &g

Re: [Ifeffit] Reported W L3-edge and L2-edge energy

2020-05-07 Thread Mike Massey
> On May 8, 2020, at 8:51 AM, Matt Newville wrote: > >  > Hi Mike, > > >> On Tue, May 5, 2020 at 10:56 PM Mike Massey wrote: >> On a tangentially related topic, I find that phosphorus K-edge XAS energy >> calibration conventions are still in a bit of

Re: [Ifeffit] Reported W L3-edge and L2-edge energy

2020-05-05 Thread Mike Massey
On a tangentially related topic, I find that phosphorus K-edge XAS energy calibration conventions are still in a bit of a "Wild West" state, with a wide variety of materials and values in use for energy calibration. As an extreme example, one or two frequently cited papers in my field from the

Re: [Ifeffit] smoothing XAS data

2020-01-22 Thread Mike Massey
At this juncture, I'd like to bring up a "rule" I've made for myself regarding data quality and smoothing: I'd rather walk away from a beam run with one good spectrum than a hundred poor ones. Meaning, for me anyway, if the data aren't smooth enough on their own, I'd rather spend more precious

[Ifeffit] X-ray analysis books available if you want them

2020-01-08 Thread Mike Massey
Hi all, I have a small selection of x-ray books I'm happy to give you if you want them. Please contact me privately if you do. I'd rather give them away to a good home than send them to book heaven. Koningsberger and Prins, X-Ray Absorption Attwood, Soft X-rays and Extreme Ultraviolet

Re: [Ifeffit] XAS fitting

2019-10-11 Thread Mike Massey
The short, short version, in my estimation, is "pick two paths as a reasonable starting point and let the fitting parameters do the rest." You could even use two clones of the same path, which will end up getting different CNs, delr, and ss in the fit. There's no law that says you have to use

Re: [Ifeffit] Two analysts, one spectrum, similar outcome?

2019-08-13 Thread Mike Massey
d things work in principle. > > The data, including a remeasured set of standards, is still available as the > EXAFS Divination Set. > > Best, > > Scott Calvin > Lehman College of the City University of New York > >> On Tue, Aug 13, 2019 at 9:41 PM Mike Massey

Re: [Ifeffit] Two analysts, one spectrum, similar outcome?

2019-08-13 Thread Mike Massey
e > individual who is seeking the answer to a different question. > > The most likely way to approach this problem is to both have the same > background information about the sample(s) and to mutually determine what > question you are trying to answer. > > Cheers, >

Re: [Ifeffit] Two analysts, one spectrum, similar outcome?

2019-08-13 Thread Mike Massey
same data." Of course, he's a strictly computational guy, so I'm not sure he necessarily has standing to criticize...(Good-natured sarcasm font...) > On Aug 13, 2019, at 6:43 PM, Anatoly Frenkel > wrote: > > Are they equally smart? > > Anatoly > >> On

[Ifeffit] Two analysts, one spectrum, similar outcome?

2019-08-13 Thread Mike Massey
quot; So I thought I'd ask. Your thoughts and experiences would be welcome. Thanks! Mike Massey ___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.a

Re: [Ifeffit] Multiple species with Artemis

2019-06-17 Thread Mike Massey
Hi Vineetha, I am aware of some people doing (or at least attempting) multi-species shell-by-shell fits, but it's a pretty daunting task, depending on your system. Another approach that some people have had success with (check papers by Martin McBriarty and colleagues) is a combination of LCF

Re: [Ifeffit] Advice on using Athena for XANES LCF on spectra with a small edge step?

2019-01-15 Thread Mike Massey
rmalization is used, I don’t know if > LCF would improve. > > Chris > > >> On Jan 15, 2019, at 8:23 PM, Mike Massey wrote: >> >> Hi Scott, >> >> >> I collect up to 2240 eV often, because that's about where the mirror stops, >> but en

Re: [Ifeffit] Advice on using Athena for XANES LCF on spectra with a small edge step?

2019-01-15 Thread Mike Massey
s, I don't have a problem. Thanks, Mike > On Jan 15, 2019, at 5:12 PM, Scott Calvin wrote: > > Hi Mike, > > Is there a reason the data stops at 2200 eV—e.g., is there another edge just > above that? > > —Scott > >> On Jan 15, 2019, at 8:02 PM, Mike

Re: [Ifeffit] Advice on using Athena for XANES LCF on spectra with a small edge step?

2019-01-15 Thread Mike Massey
line is not > in the right place. You need to tune it by hand when you have such a short > energy range after the edge since the normalization is critically dependent > on how you set this line. > > carlo > >> On Tue, 15 Jan 2019, Mike Massey wrote: >> >&g

Re: [Ifeffit] Advice on using Athena for XANES LCF on spectra with a small edge step?

2019-01-15 Thread Mike Massey
Thanks for the response! I should clarify, the data are collected in fluorescence, concentration is perhaps in the hundreds of ppm to tenths-of-percent range in this case. Personally I haven't had great luck with self-absorption correction in the past (actually I've had basically no luck), so

Re: [Ifeffit] 32ビット版アプリケーションの申請

2018-08-22 Thread Mike Massey
Just in case this might help... "Dear Maintainers of Ifeffit, I would like to use the 32-bit version of the application. Would you mind posting a 32-bit version of the installation application? Thank you very much." > On Aug 22, 2018, at 9:25 PM, 天田雄大 wrote: > > Ifeffit管理者様 > >

Re: [Ifeffit] LCF on Larch - EXAFS Region

2018-08-12 Thread Mike Massey
> Hi Mike, > >> On Thu, Aug 9, 2018 at 10:04 PM Mike Massey wrote: >> This is interesting. Could you say more about your skepticism of the >> robustness of EXAFS LCF, Matt? >> >> To be fair, it suffers from many of the same drawbacks of XANES LCF, plus >> othe

Re: [Ifeffit] LCF on Larch - EXAFS Region

2018-08-09 Thread Mike Massey
This is interesting. Could you say more about your skepticism of the robustness of EXAFS LCF, Matt? To be fair, it suffers from many of the same drawbacks of XANES LCF, plus others. But I'm curious about your thoughts on it since yours seems to be what amounts to a "strong opinion" on the

Re: [Ifeffit] iron carbide fitting with Artemis

2017-10-26 Thread Mike Massey
* this list contains 221 atoms > * x y z ipot tag distance > 0.00.00.0 0 Fe1 0.0 >0.0 0.01.94335 4 C1.11.94335 > > Thanks a lot for your help again! > > Best, >

Re: [Ifeffit] iron carbide fitting with Artemis

2017-10-26 Thread Mike Massey
I definitely recommend combining multiple atoms of similar distances into the same path. That's what you end up with anyway if you use multiple paths, with a lot more potential problems in the software. Sometimes it is beneficial to split a shell of of atoms into two, to capture some physical

Re: [Ifeffit] Athena and "norm" file groups

2016-10-15 Thread Mike Massey
factum normalization to the > normalized data. > > Anatoly Frenkel > Stony Brook University > > >> On Oct 15, 2016 4:10 PM, "Mike Massey" <mmas...@gmail.com> wrote: >> Hi everyone, >> >> >> Apologies if this has been covered before

[Ifeffit] Athena and "norm" file groups

2016-10-15 Thread Mike Massey
Hi everyone, Apologies if this has been covered before, I'm just getting around to upgrading to Demeter. I have a bunch of old project files with a mishmash of data from different sources, and I'm having trouble getting them to work fully with the new software. Any group with a data type of