Moneeb,
I'm in the middle of beam run, so I am forwarding this along to the Ifeffit mailing list for commentary. B ---------- Forwarded Message from Moneeb Shatnawi <Moneeb Shatnawi <[EMAIL PROTECTED]>> ---------- Subject: average first shell position and width Date: Wednesday 27 June 2007 From: Moneeb Shatnawi <[EMAIL PROTECTED]> To: Bruce Ravel <[EMAIL PROTECTED]> Dear Dr. Ravel, Hello, I am Moneeb Shatnawi from physics department at Michigan State University, I have a PDF and XAFS data on GeSe system, and I would like to check if the PDF and XAFS results are consistent with each other in terms of the first PDF peak position and width. The first PDF peak in this system is a mixed shell of Se-Se bonds as well as Ge-Se bonds. The PDF data gave a width of the first PDF peak of about 0.06 A, and the XAFS data gave sigma^2 for Ge-Se bond is 0.006 A^2, and for Se-Se bond is 0.003 A^2. How is sigma in XAFS results (I was using Artemis program) related to the width of the first PDF peak? Also, when obtaining the XAFS fits to the data, I was using: Theory ---> first shell fit. In this, I was giving r_eff for Se-Se bond to be 2.32 A and that for Ge-Se to be 2.368 A. Through the XAFS refinement, I obtained r, dr as well as r_eff. which of these should be considered as the actual bond length (r or r_eff)? and how are these related to the average position that I get from fitting the first PDF peak in this system? I appreciate your help, Thanks, Moneeb ------------------------------------------------------- -- Bruce Ravel ---------------------------------------------- [EMAIL PROTECTED] Molecular Environmental Science Group, Building 203, Room E-165 MRCAT, Sector 10, Advanced Photon Source, Building 433, Room B007 Argonne National Laboratory phone and voice mail: (1) 630 252 5033 Argonne IL 60439, USA fax: (1) 630 252 9793 My homepage: http://cars9.uchicago.edu/~ravel EXAFS software: http://cars9.uchicago.edu/~ravel/software/ _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit