Thank you so much for many experts replay.

Lithium tantalate crystal is R3c space group and actually have many hole at Li site . I think that Fe should be replaced to Li or implemented to the absent site. At first, I made the structure which was exchanged Li to Fe, but this structure was not fitted to the data. So that , I changed z value of Li of atoms on the input data to smaller and changed Li to Fe. I used default GDS parameters for the fitting because my knowledge of how-to manipulating GDS is not enough. I used 6 paths for the fitting. 1-3.4(1/k) range and kw=1 was used. Should I think about all paths? (Feff calculation makes 170paths). I received ZnO tutorial file from Dr.Fons last month. I studied the tutorials two or three times, but I could only have little knowledge what the meanings of the GDS parameter manipulations, because of my little knowledge of XAFS principals. I will read some XAFS tutorials. And, I will try some other structures and try more paths in fittings.

Thank you.

----- Original Message -----

From: Joji Kuniya

Sent: Monday, May 28, 2007 7:51 PM

Subject: [Ifeffit] Low amp results

I analyzed EXAFS spectra of trace of Fe in lithium tantalate crystals. At first, I created the feff.inp file of LiTaO3. Then I changed central Li atom to Fe atom and added Fe atom at the Ta site. So that, the fitted results is good except amp(amp results is 0.3). I think that the model structure is good, but I can not understand why amp is too low. How do you think about this results? And, I tried to fitting treatment using GDS parameters. But, I do not know that the general method how to use the GDS parameters. Please tell me the general way of GDS manipulation. My PC runs under Win XP, and My Artemis runs under feff8 conditions. Thank you.