I had a quick question about using the multiple pole MPSE card in feff that I was hoping that you are someone at the feff team could answer. I note that there is a example file provided with jfeff for Cu that includes such loss.dat file, but there is no documentation on how the file was generated. As it is different from the OPCONS constructed file, I assume it is either experimental or theoretical data. I am curious to try and see if I can improve the reliability of feff’s predictions for GeTe and am curious if including a loss.dat file would help on this account. The default Ge K-edge spectra exhibits some discrepencies with experiment that I would like to see if the multi-pole card can help clear up. The feff wiki (
http://leonardo.phys.washington.edu/feff/wiki/static/u/s/i/Using_the_Many-Pole_Self_Energy_(MPSE)_4a64.html) states that Wien2K can be used to produce such a loss function. Among the packages the Wiki suggests to use for generating the loss.dat file is Wien2K. I routinely use Wien2K and am using the latest version of this writing 14.2. I assume the energy loss function would be calculated using the TELNES3 module of Wien2K.
I have reproduced the “front end” input for the TELNES3 settings. Would you have any suggestions (or can you forward this message to someone who might have suggestions) as to how to calculate the loss function in my case? I should add that the loss.dat file in the Cu example included with jfeff has an extraordinarily large range (0-10^5 eV) of energies specified. I doubt Wien2K can be used to calculate spectra over this energy range so please advise if there is a need to combine the Wien2K output with additional data (perhaps from a OPSCON card output?).