[Ifeffit] Linear Combination Fit

Saugata Datta saugatadatta at hotmail.com
Tue May 10 00:01:49 CDT 2011


Dear Iffefit group.,
 
I am just starting to know this forum, and I read some messages from time to time and find it very useful., I have a question on the Linear Combination Fitting--using to fit my sample with a few standards.
I am experiencing that on some iterations of the fit (which gives good reduced chi square value, / good R Factor values) but shows  the following, as an example:
Standard  Weight                             E0
X             0.267(0.056)                     0
Y              0.249 (0.017)                   0
M             0.220 (0.015)                   0
N             0.428 (0.055)                   0
P             0.000 (0.082)                   0
 
Now, I am confused about this "P" standard...as it shows 0.000 (weight);  should I even choose this iteration, or will go to the the next one? 
 
And the next question is: if the addition of all weigths is 0.999 or 1.164 --- can I consider them? What I mean is: what is the range of acceptance of sum of all weights (I am chqing the check box for force weights to sum to 1)?
 
thanks for your anticipated help.
 
saugata
 
 
 
 
 
> Date: Mon, 9 May 2011 15:19:05 -0700
> From: garcia.ff.000 at gmail.com
> To: ifeffit at millenia.cars.aps.anl.gov
> Subject: [Ifeffit] Linux command line ff2chi yields no output
> 
> Dear users,
> 
> I was able to install iffefit on linux. From the command line I run:
> 
> feff6 feff.inp
> 
> This worked fine and several feffnnnn.dat files were generated. Then,
> I wrote an input script, tmp.iff (shortened list of paths here), for
> ifeffit as follows:
> 
> # tmp.iff
> 
> path(1, file=feff0001.dat, s02 = 0.9, sigma2 = 0 .001)
> path(2, file=feff0002.dat, s02 = 0.9, sigma2 = 0 .001)
> path(3, file=feff0003.dat, s02 = 0.9, sigma2 = 0 .001)
> path(4, file=feff0004.dat, s02 = 0.9, sigma2 = 0 .001)
> path(5, file=feff0005.dat, s02 = 0.9, sigma2 = 0 .001)
> path(6, file=feff0006.dat, s02 = 0.9, sigma2 = 0 .001)
> path(7, file=feff0007.dat, s02 = 0.9, sigma2 = 0 .001)
> path(8, file=feff0008.dat, s02 = 0.9, sigma2 = 0 .001)
> path(9, file=feff0009.dat, s02 = 0.9, sigma2 = 0 .001)
> path(10, file=feff0010.dat, s02 = 0.9, sigma2 = 0 .001)
> path(11, file=feff0011.dat, s02 = 0.9, sigma2 = 0 .001)
> 
> ff2chi(1-11, group=mycalc)
> 
> fftf(mycalc.chi, kmin=1, kmax=15, dk=0.5, kweight=2.0, kwindow='hanning')
> 
> #
> 
> My aim here is to sum the paths to generate chi(k). Now if I run the
> following command:
> 
> ifeffit -x tmp.iff
> 
> the following output is printed on the screen:
> 
> reading feff0101.dat
> reading feff0102.dat
> reading feff0103.dat
> reading feff0104.dat
> reading feff0105.dat
> reading feff0106.dat
> reading feff0107.dat
> reading feff0108.dat
> reading feff0109.dat
> reading feff0001.dat
> reading feff0002.dat
> reading feff0003.dat
> reading feff0004.dat
> reading feff0005.dat
> reading feff0006.dat
> reading feff0007.dat
> reading feff0008.dat
> reading feff0009.dat
> reading feff0010.dat
> reading feff0011.dat
> 
> It appears that the feffnnnn.dat files were read successfully.
> However, no mycalc.chi output was produced by ff2chi() [and therefore
> no mycalc.chir_* output was produced by fftf()]. I don't know if my
> approach is missing an important step or my entire procedure is
> nonsensical.
> 
> 
> Thanks a lot!
> _______________________________________________
> Ifeffit mailing list
> Ifeffit at millenia.cars.aps.anl.gov
> http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit

 		 	   		  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachments/20110510/c629edb5/attachment.html>


More information about the Ifeffit mailing list