Hello, 

If you have done a DFT calculation, you can take the atom coordinates from the calculation and just put them directly into a Feff input file. No need to use atoms. 

If you are not sure how to build a feff input file, you can run a dummy atoms file with Zn to get a rough template and work with the Feff users manual to determine how to set the parameters.

Jeff





On Mar 8, 2012, at 11:13 PM, winejar8324 wrote:

Hi everyone! can u please help me?


I was so glad that Prof. J F W Mosselmans gave me advice about EXAFS analysis of complex solution system in last time.
 
Here i have an another question about how to bulit ATOM to obtain FEFF by using DFT model.
 
When getting a reasonable zinc complex model caculated by Density Functional Theory, i wish use it to clarify the experimental EXAFS data. But i don't know how to bulit ATOM file using this model. Except for the coordinates in the DFT output file, i don't know how to get the other structure information including space, cell parameter etc.
 
*********************************
title=name
space=?
a=? b=? c=?
alpha=? beta=?  gamma=? ( How to get these data? )
rmax = 8.0  
core = Zn1 
atom
Zn 0 -0.25 -0.125 Zn1 1 (I can get the atom coordinates from the DFT output file)
.......
 
*******************************
 
Is there any other methods to create the corresponding ATOM file?
 
Thank you very much.
winejar
 
 
2012-03-09
发件人： Takahide Yamaguchi
发送时间： 2012-03-08  16:00:36
收件人： ifeffit
抄送：
主题： [Ifeffit] what is the reasonable arc-tan for edge jump
Dear all,

I was so glad that Bruce and Zajac gave me advice about MS path treatment in last time.
Thank you very much.

Now, I am working on analysis of Cu K edge by using EDG_FIT, following previous papers.
I am wondering if someone gave me comment about current problem for me.
And my question about XANES analysis is "what the reasonable arc-tan is as a back ground of XANES."

In previous some papers, Cu K edge were deconvoluted by assuming arc-tan edge jump function.
But I couldn't found the reasonable mention for the shape of arc-tan.

For example of Cu(II), one paper (1), which has interest in the metalloproteins active site,
the arc-tan were positioned around 8992 eV with 5 eV hwhm approximatly. 　
But in another paper (2), which reported about high valence Cu(III),
the arc-tan for Cu(II) complex looks having narrow hwhm at higher positons (around at 8984 eV).

(1) J. Phys. Chem. B 2000, 104,10814-10819
(2) JACS 2000, 122, 5775-5787
 
Are there any reason which can explain these difference?

I hope any comment and advice.

Takahide
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