On Thursday 09 February 2006 01:57, Michel Jaouen wrote:
Now a question about Hephaestus: for f' and f" one has rodio buttons allowing to select among various set (Crmer Liberman, Henke, ..). I have try to select several and it always return CL! Why and how to fix this (not sure it is a bug but?).
To quote from the Hephaestus document about the f'/f" utility: This utility plots the complex corrections to the scattering factors for the elements. i.e. the energy dependent f'(E) and f"(E) terms. These functions are tabulated from the Cromer-Liberman calculations for the isolated, neutral atom. The selection in the Resource menu is ignored. That's by design. The reason is that I have never been able to figure out how to do the interpolation off of Chantler's ffast tables near the absorption edges such that the f' function is well behaved near the absorption edge. The dteails are at http://physics.nist.gov/PhysRefData/FFast/Text/cover.html. The last time I looked at this in detail, my implementation gave very poor results in the region of f' that was changing quickly. B -- Bruce Ravel ---------------------------------------------- bravel@anl.gov 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/exafs/