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