question about type of broadening applied for DOS

[yping]

Dear developer,

I have a question about the type of broadening used for density of states by ypp.x:

In my calculation, I assume the interpolation scheme is not used as I used default GfnQP_N=1;
the result looks quite broadening with less peaks than a simple Gaussian broadening I expect.
I wonder whether the type of broadening function is a simple Gaussian broadening or some more complicated implementation is involved.
I was looking for the code for this part but not exactly sure where it's located. Hopefully you can help me confirm this.

# GPL Version 3.4.1 Revision 3187
# http://www.yambo-code.org
#
electrons # [R] Electrons (and holes)
dos # [R] DOS
GfnQPdb= "E < SAVE/ndb.QP" # [EXTQP G] Database
GfnQP_N= 1 # [EXTQP G] Interpolation neighbours
% GfnQP_E
0.000000 | 1.000000 | 1.000000 | # [EXTQP G] E parameters (c/v) eV|adim|adim
%
% GfnQP_Wv
0.00 | 0.00 | 0.00 | # [EXTQP G] W parameters (valence) eV|adim|eV^-1
%
% GfnQP_Wc
0.00 | 0.00 | 0.00 | # [EXTQP G] W parameters (conduction) eV|adim|eV^-1
%
GfnQP_Z= ( 1.000000 , 0.000000 ) # [EXTQP G] Z factor (c/v)
% DOS_bands
5 | 40 | # DOS bands
%
DOSESteps= 500 # Energy steps
DOS_broad= 0.20000 eV # Broadening of the DOS
#PrtOccOnly # Occupied states only

Thank you so much in advance!

Yuan Ping
Materials Postdoc Fellow
Joint Center for Artificial Photosynthesis (JCAP)
Lawrence Berkeley National Laboratory &
California Institute of Technology

[Daniele Varsano]

Dear Yuan,
the broadening it is not a gaussian, but enters a temperature in a derivative of a Fermi Function (which mimics a delta function).
You can reduce the broadening by reducing the DOS_broad variable (0.2eV is rather large) and also playing with DOSESteps.

Best,
Daniele