Hi Matthew,
On Mon, Apr 4, 2011 at 5:51 PM, Matthew Marcus
OK, so if you don't add a sigma2 to your FEFF input file, then IFEFFIT will do the correction properly. Another question is whether, if you add a sigma2 to feff.inp, what does FEFF do? mam
FEFF's ff2chi module does apply sigma2 to the complex photoelectron wavenumber. It does not make the correction for the 1/R^2 term described by Tranquada and Ingalls. Like Bruce says, for general use, putting sigma2 and S02 in feff.inp can be somewhat confusing, as these are not applied to the feffNNNN.dat files that feffit/ifeffit/artemis uses, but only to the chi.dat file. In some sense, feffit/ifeffit/artemis were written as replacements for FEFF's ff2chi module, summing path contributions with sigma2, S02, and a few more bells and whistles. --Matt