Of course, XAFS *is* a one-dimensional probe, not a three-dimensional one. At least ignoring for the moment the angular dependence of multiple scattering, XAFS is sensitive to g(r) only. Sadly, this is sometimes forgotten in the literature, and one sees attempts to distinguish "sigma^2_perpendicular" and "sigma^2_parallel", which is a good sign of a paper that is complete nonsense. I don`t agree with you in this point. To my understanding, because EXAFS is a one-dimensional probe and it measures the average over instantaneous inter-atomic distances, it is only sensitive to the motion relative to each other along the bond-direction - and thus measures sigma^2_parallel. Combined with XRD which measures the the atomic motion averaged over all directions one can then extract a "sigma^2_perpendicular". If we are talking about the same literature
Hi Matt, this point is well elaborated in there and I don`t think it is nonsense. Please correct me if I am wrong. Cheers, Patrick --------------------------------------------------------------------- Dr. Patrick Kluth Fellow, ARC Australian Research Fellow Department of Electronic Materials Engineering Research School of Physics and Engineering The Australian National University Canberra, ACT 0200 AUSTRALIA Phone: +61 2 6125 0358 Fax: +61 2 6125 0511 Mobile: +61 408 66 31 04 Email: patrick.kluth@anu.edu.au http://www.rsphysse.anu.edu.au/eme ---------------------------------------------------------------------