Re: [Ifeffit] Looking for the XAS of Zn3P2

[Peloquin, Derek]

I don't know if it's the only journal article that has used it, but 
https://pubs.acs.org/doi/10.1021/acs.chemmater.9b04407 has a Figure 2 that 
looks at Zn3P2 as confirmation for their synthesis of In(Zn)P quantum dots (no 
affiliation with any of the authors). If no one else gets back to you here, I 
have found success before in doing an internet search and then contacting the 
authors directly. 

-Derek

Derek Micheal Peloquin, Ph.D. (he/him)
Postdoctoral Physical Scientist

US Environmental Protection Agency
Office of Research and Development
Center for Environmental Solutions and Emergency Response
Land Remediation Technology Division
Contaminated Sites and Sediments Branch

-Original Message-
From: Ifeffit  On Behalf Of 
Madeleine Han
Sent: Friday, April 16, 2021 8:59 AM
To: ifeffit@millenia.cars.aps.anl.gov
Subject: [Ifeffit] Looking for the XAS of Zn3P2

Dear Ifeffit community,

I am looking for the X-ray absorption spectrum of Zn3P2 to use as a reference 
to determine the composition of an unknown compound. Does anyone know if it has 
already been recorded? If so, where can I find it?

Thank you in advance for your help,

Yours sincerely

Madeleine Han

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Re: [Ifeffit] Question on (Combo-) LCF plot output

[Peloquin, Derek]

Hello Teresa,
I'll throw my meager two cents in to say that I'm not sure why it is happening 
that way, but I can replicate what you are seeing. It seems like it might be a 
problem with the "All standards share an E0" box because when I directly input 
those first results (with the 1.631 E0 shift) into the weight and E0 boxes, and 
click "Plot data and sum," it lines up very nicely. But then even when I run 
the "Fit all combinations" with that "All standards share an E0" box checked, 
every output is shifted and I think you would be fine understanding that it is 
working that way and then just going back again and putting the numbers in 
directly and "plot data and sum" if you want the better looking plot for your 
dataset.

I usually like to "Fit all combinations" to get the full set of possibilities 
but depending on the number of standards you allow it to use and how many 
you're checking against to begin with, this can get a bit processor-intensive 
sometimes and working through the quick fitting first to eliminate some options 
works well in my opinion.

-Derek

---
Derek Micheal Peloquin, Ph.D.
ORISE Postdoctoral Research Participant

US Environmental Protection Agency
Office of Research and Development
Center for Environmental Solutions and Emergency Response
Land Remediation Technology Division
Contaminated Sites and Sediments Branch
5995 Center Hill Ave
Cincinnati, OH 45224
Office: (513) 487-2670

-Original Message-
From: Ifeffit  On Behalf Of 
t.zahoran...@mineralogie.uni-hannover.de
Sent: Monday, March 30, 2020 5:05 AM
To: ifeffit@millenia.cars.aps.anl.gov
Subject: [Ifeffit] Question on (Combo-) LCF plot output

Dear Mailing list,

I am a relatively new user in terms of XAS data handling and I encountered a 
strange problem during LCF in Athena.
I am working on LCF-combo fittings for Mn minerals as described in Manceau et 
al. 2012*.

Fitting f.ex. a cryptomelane sample of myself with the open source monovalent 
manganese mineral standards of Manceau et al. 2012 in a fit range of -20 to +30 
k, gives the following result shown below (I´ll attach the Athena project):

" LCF fit of Cryptomelane_T_20K_ecd as flattened mu(E) from 6536.79 to 6586.79 
Fit included 100 data points and 6 variables, and approximately 41.333 
measurements Weights sum to 1: no Weights forced between 0 and 1: no Overall e0 
shift used: yes Noise added to data: 0 R-factor = 0.0003537 Chi-square = 
0.00815 Reduced chi-square = 0.858

.standard weight   e0

.   Manganosite.dat   0.042 (0.006)1.631 (0.044)
.   Groutite.dat  0.030 (0.029)1.631 (0.044)
.   Ca2Mn3O8.dat  0.288 (0.026)1.631 (0.044)
.   Ramsdellite.dat   0.584 (0.022)1.631 (0.044)
.   Mn2O3.dat 0.044 (0.025)1.631 (0.044)

. sum ... 0.988  "

Note that the box “all standards share an E0” is checked before clicking on 
“Fit this group”. Optically, the fit itself “looks” good compared to the data, 
yet, it is somewhat shifted on the x-axis compared to the data. I was wondering 
why, as this was not the first sample where this was the case.

When I now uncheck the “All standards share an E0” box, leave everything else 
just the way it is and just click “Fit this group”  
again, the fit suddenly is shifted perfectly on my data. The strange thing is: 
Nothing else in the output-results changes – weights, R-factor, chi-square etc. 
just stay the same. Only slight changes in the numbers in brackets after the 
reported weights. The "new" result is:

" LCF fit of Cryptomelane_Mikon_T_20K_ecd_reb-a-m as flattened mu(E) from 
6536.79 to 6586.79 Fit included 100 data points and 5 variables, and 
approximately 41.333 measurements Weights sum to 1: no Weights forced between 0 
and 1: no Overall e0 shift used: no Noise added to data: 0 R-factor = 0.0003537 
Chi-square = 0.00815 Reduced chi-square = 0.849

.standard weight   e0

.   Mn2O3.dat 0.044 (0.024)1.631 (0.000)
.   Manganosite.dat   0.042 (0.006)1.631 (0.000)
.   Ca2Mn3O8.dat  0.288 (0.024)1.631 (0.000)
.   Ramsdellite.dat   0.584 (0.019)1.631 (0.000)
.   Groutite.dat  0.030 (0.026)1.631 (0.000)

. sum ... 0.988 "

Can anybody tell me, what is actually happening? I exported both data to excel 
to replot the fits to exclude a simple plot-bug, but the data behind show that 
this is real. So, I am changing the data behind the plot, but actually not the 
output data … what is going on here?

You find the project attached – I hope someone can tell me, how to cope with 
that!

Thank you very much,
Teresa


*Manceau, A., Marcus, M. A., & Grangeon, S. (2012). Determination of Mn valence 
states in mixed-valent manganates by XANES spectroscopy.  

Re: [Ifeffit] Postdoc

[Peloquin, Derek]

Hello Mathieu,
It looks like the link just got copied into hyperlink form incorrectly.  I'm 
pasting it here with it fully hyperlinked to help out.

https://lbl.taleo.net/careersection/2/jobdetail.ftl?lang=en=83928

-Derek

---
Derek Micheal Peloquin, Ph.D.
ORISE Postdoctoral Research Participant

US Environmental Protection Agency
Office of Research and Development
National Risk Management Research Laboratory
Land and Materials Management Division
Emerging Chemistry and Engineering Branch
5995 Center Hill Ave
Cincinnati, OH 45224
Office: (513) 487-2670

From: Ifeffit [mailto:ifeffit-boun...@millenia.cars.aps.anl.gov] On Behalf Of 
mathieu le meur
Sent: Saturday, July 22, 2017 10:53 AM
To: ifeffit@millenia.cars.aps.anl.gov
Subject: [Ifeffit] Postdoc

Hello
I am very interested with the postdoc doc position with  Corwin H. Booth
Unfortunately, the link is not working and I cannot apply.
Can you help me?
Thanks,
Mathieu.
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