[Ifeffit] Error in second shell fit

Wed Feb 20 10:13:18 CST 2013

Dev,

As Bruce points out, the error message is somewhat ambiguous.  There is a
setting in (D)Artemis, completely separate from the Feff calculation, that
allows one to set the range in R-space of your data that is fit with the
chosen paths you include from the Feff calculation.

I would also say that this is not really an error, per se, but more of an
warning.  I am not at my computer right now but I will  send a highlighted
screen show of Artemis and where one would change the R-space range value
for rmax.

I hope that clears up the confusion,

Chris

On Wed, Feb 20, 2013 at 10:54 AM, Devender <devend at rpi.edu> wrote:

> Dr. Patridge,
>
> Thanks for suggestion. I am not sure if I get completely, I do understand
> the difference of Rmax in artemis and feff. You mean make changes in rmax
> in feff input file? I did that and attached are screenshots for that but I
> am still getting the same error. Let me know if I interpreted your
> suggestion wrongly.
>
> Dr. Kicaj, I am studying doping problems and it's important I get fitting
> from second and subsequent shells as there are new peaks that shows up at
> higher radial distances.
>
> Regards,
> Dev
>
>
> On Wed, Feb 20, 2013 at 8:26 AM, Christopher Patridge <
> patridge at buffalo.edu> wrote:
>
>>  Dev,
>>
>> I don't know if my email was received.  The think the problem is what you
>> interpret as rmax.  Rmax in artemis is the maximum value of R that you fit
>> the data with, whereas rmax in feff is the largest distance from the center
>> absorbing when calculating all the paths.
>>
>> The reason changing the rmax in feff does remove the error is that you
>> must change the fitting range in (D)Artemis.  I think the default vaue is ~
>> 3 A.
>>
>> Chris
>>
>> ********************************
>> Christopher J. Patridge, PhD
>> NRC Post Doctoral Research Associate
>> Naval Research Laboratory
>> Washington, DC 20375
>> Cell: 315-529-0501
>>
>>  On 2/20/2013 3:13 AM, "Dr. Dariusz A. Zając" wrote:
>>
>> Dev,
>>
>> I work with older Ifeffit version thus I can not help you much - I can
>> not open (Artemis) or work (Athena) with projects...
>> I have only one question - do you need to fit paths about 4A?
>>
>> I hope that someone on this mailing list will check your files
>>
>> regards
>> kicaj
>>
>>
>> W dniu 13-02-19 17:47, Devender pisze:
>>
>> Dr. Kicaj,
>>
>> I tried that too, went till 8 A, but it is still showing same error
>> whereas R effective for second shell paths are 4.4 and 4.7 A. I have also
>> attached athena file and artemis project file for my data for reference.
>>
>> -Dev
>>
>> On Tue, Feb 19, 2013 at 10:57 AM, "Dr. Dariusz A. Zając" <
>> kicaj at ifj.edu.pl> wrote:
>>
>>> Hi,
>>>
>>> could you check if the same  error appears if you give the Rmax of,
>>> let's say, 8A or even 6.5A?
>>> For higher R, the paths sometimes does not look like a single "gaussian"
>>> peak, but has some kind of "satellites". You have to also remember that
>>> each path consists of the real and imaginary part.
>>>
>>> Regards
>>> kicaj
>>>
>>>
>>>
>>> W dniu 13-02-19 16:42, Devender pisze:
>>>
>>>  Hi,
>>>
>>> I am trying to fit Bi2Te3 exafs data using artemis. I am able to fit
>>> first shell (screenshot of fit is attached, I have also attached 'atoms'
>>> and 'feff' files for reference) but when I am trying to include second
>>> shell, I am getting the error (attached file- Fit_error.log). Error reads
>>> that- "The R effective for this path is well beyond the rmax value of its
>>> Data object." but I am already using Rmax of 6 A and Reff of these path are
>>> less than 5 A in my fit. I will appreciate if anyone can guide me or point
>>> me where I am making mistake.
>>>
>>> Regards,
>>> --
>>> Devender
>>> Graduate Student, Materials Science and Engineering
>>> Rensselaer Polytechnic Institute, Troy, NY
>>> Website <https://sites.google.com/site/devendermaun/>
>>>
>>>
>>>
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>>>
>>>
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>>
>>
>> --
>> Devender
>> Graduate Student, Materials Science and Engineering
>> Rensselaer Polytechnic Institute, Troy, NY
>> Website <https://sites.google.com/site/devendermaun/>
>>
>>
>>
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>>
>>
>>
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>
>
> --
> Devender
> Graduate Student, Materials Science and Engineering
> Rensselaer Polytechnic Institute, Troy, NY
> Website <https://sites.google.com/site/devendermaun/>
>
>
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>

-- 
Christopher J. Patridge PhD.
Contact: (315)-529-0501
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