SO2CONV will convolute the single particle XAS files (`xmu.dat',
`chi.dat', `feffNNNN.dat', etc.) from FEFF with a many
body spectral function, to include many body effects in the spectra.
This includes an ab-initio calculation of the amplitude reduction
factor S. SO2CONV uses Hedin-Lundqvist self energies, so it
will probably work best with XAS files calculated using FEFF's
HL self energies.