Dear Bruce,
I have trouble running the Demeter 0.9.26_pre2 (64bit). When I start
Artemis after installation of Demeter, it closes after showing nothing
but the usual temple picture. Logfile is attached. The problem is
analogous on both Win7 SP1 and Win8.1 and repeats also for Athena and
Hephaestus. Could you please tell whether there is something I can do
to fix it? Versions 0.9.25 and 0.9.24 start without problems.
I know that 0.9.26 is a preview version, but I was installing it only to …
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get the possibility to actually use the user-supplied value of epsilon_k
for fitting multiple dataset. If it is difficult to make the version
0.9.26 available soon, maybe in 0.9.25 there is a possibility to set
R-factor as a figure of merit for fitting rather than chi^2? That might
also help.
Thank you
All the best,
Kirill Lomachenko
--
Dr. Kirill A. Lomachenko
Scientist at BM23/ID24 beamlines
European Synchrotron Radiation Facility (ESRF)
71 avenue des Martyrs
CS 40220
38043 Grenoble Cedex 9, France
Tel: +33 438 88 19 14
www.esrf.eu
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Hi everyone,
I've recently collected some V K-edge XANES spectra and am in the process
of analysing the data. The pre-edge region has been shown to be quite
useful for exploring the oxidation state and coordination geometry of
vanadium in various samples. This approach requires the pre-edge peak area
and centroid of unknowns to be compared with those of a suite of standards,
with these parameters typically determined by fitting a peak (or peaks) to
the pre-edge feature. The attached paper by …
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of how this is often done, but it raised a question in my mind that I
wanted to clarify before proceeding to analyse my data in this way...
Is it necessary to justify a particular selection of peak fitting
parameters based on physical attributes? For example, Chaurand et al fits
multiple pseudo-voigt peaks to the V pre-edge feature, with the Lorentzian
contribution to this pseudo-voigt function constrained to be the same as
the core-hole lifetime width at the V K-edge (i.e. 0.8 eV). The Gaussian
contribution is allowed to vary, but the Lorentzian to Gaussian intensity
ratio is set at 1:1. After justifying these parameters, the authors go on
to say that *"It should be noted that width and height of the modeled
pseudo-Voigt functions have little physical significance, being a
convolution of two functions with significantly different width."* If this
is the case, does it really matter what specific peak fitting parameters
are used? If the goal is to simply obtain an accurate peak area and
centroid of the pre-edge feature, wouldn't an empirical peak fitting
approach provide comparable data? I'm not against fitting a series of
pseudo-voigt functions constrained in a similar way, to my data, but I'd
like to have a good justification for doing so.
I'm quite new to the world of peak fitting in the context of XAS data
analysis, so I'm looking forward to hearing the views of the mailing list.
Thanks in advance.
Will
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Hello all,
I hope I'm not overstepping any bounds here, but I know that this mailing
list is populated with both experimentalists and theorists, so I figured
the email could be of interest.
The University of Maine is looking to hire a theoretical/computational
condensed matter physicist for a tenure track Assistant Professor
position. I have attached the ad and the link to the position can be found
here:
https://umaine.hiretouch.com/job-details?jobID=44990&job=assistant-professo……
[View More]Please feel free to circulate as you see fit.
Regards,
Rob Meulenberg
Robert W. Meulenberg
Associate Professor of Physics
Laboratory for Surface Science and Technology
Department of Physics and Astronomy
University of Maine
Orono, ME 04469
phone: 207-581-2245
email: robert.meulenberg(a)maine.edu
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