Hi,

Thanks for using exciting and positive feedback!!!
Frankly speaking, "spectralfunctionplot" in the current version is not 100% reliable and should be treated as "under development". Therefore I did not intend to make it visible :-) Although you may still try to use it. For this, you should first complete "g0w0" task first.
And after that, one needs just to switch the task to:

taskname="sepl"

and specify parameters for the plot:
<selfenergy
actype="pade"
singularity="mpb"
>
<SpectralFunctionPlot
axis="real"
nwgrid="1000"
wmin="-2.0"
wmax="1.0">
</SpectralFunctionPlot>
</selfenergy>

This should generate a group of files. The spectral function data is in "SpectralFunction.dat"
For each irreducible k-point, the An(k,w) is printed in a format convenient for visualization, e.g., with GnuPlot:
first column - w
2, 3, … columns - states from "ibgw" to "nbgw"

FYI, I'm about to make public a new version of GW code with a bunch of new features. One of them is a more precise treatment of the frequency dependency (W(w), A(w), Sigma(w)). Please contact me directly, if you're interested in testing new features before the new release.

Best regards,
Dmitrii
(the exciting developer team)

Hi Laurent,

That'd indeed be great to plot An(k,w) along a path… But unfortunately, due to some specifics of the implementation, it's not so straightforward. At the moment, the only solution I could suggest (and what I'm actually using) is to try to compute GW with as dense as possible k-grids and extract the required k-path points manually.

There are, however, some other workaround approaches we could try ;-)
Best,
Dmitrii

Ups! I've just realized that it is hardcoded to print only the first (Gamma) point.
The solution would require to remove lines 272, 273 in src/src_gw/plot_selfenergy.f90 and recompile the code.