[Ifeffit] convergence of XANES for STO

[Lena Fitting]

Hi Feng,

Thanks for your reply.
I've already tried to increase the broadening, but that results in 
spectra with a resolution worse than that of the experimental results.

Regards,
Lena


Feng Wang wrote:
> Hi Lena,
>
> It is no suprising to see the change of the fine structure near the edge 
> within a cluster of that size, because of the long mean free path of the 
> photoelectron. 
>
> You used a broadening of 0.2eV in your FEFF input, which should give you 
> more details than your experiments. 
>
> Good luck,
>
> Feng
>
>
>   
>> Dear all,
>>
>> I have a question regarding the convergence of XANES calculations. I'm 
>> currently focusing on the O-K edge of perovskite oxides, in particular 
>> SrTiO3 and found that there are still fine-structure changes for large 
>> (9.5Å) clusters. Attached is my *.inp file for the 9.5Å cluster and a 
>> summary of the XANES for increasing cluster sizes from 6.5Å to 9.5Å. You 
>> can see that there are still significant changes as the cluster size is 
>> increased from 8.5 to 9.5Å. In particular, I find a double peak feature 
>> in the first 5eV after the edge onset, which is not observed 
>> experimentally. Do you have any suggestions how to obtain a better 
>> convergence?
>>
>> Secondly, if you compare the simulated XANES with experimental results 
>> (see attachment: EELS STO.png), I'm not able to match all three main 
>> peaks, even by scaling the energy scale. Are the deviations I'm seeing 
>> within the accuracy of FEFF or do I need to improve my *.inp file?
>>
>> Best regards,
>> Lena
>>
>> ---------------------------------
>> Lena Fitting Kourkoutis
>> E13 Clark Hall
>> Cornell University
>> Applied and Engineering Physics
>> Ithaca, NY 14853
>>
>> phone: 607-255-0654
>> e-mail: lf56 at cornell.edu
>> ---------------------------------
>>     
>
>
>
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-- 
---------------------------------
Lena Fitting Kourkoutis
E13 Clark Hall
Cornell University
Applied and Engineering Physics
Ithaca, NY 14853

phone: 607-255-0654
e-mail: lf56 at cornell.edu
---------------------------------