Is the correction for occupation important?

[zsjan]

Dear all:
After obtaining the energy correction from G0W0, we get a new group of eigenvalues, which should redefine the occupation of elections. So is this occupation correction important for the calculation of optical spectra since the contribution of spectra comes large part from the unoccupied states. Thank you!

[Daniele Varsano]

Dear Shijun,
of course it depends on the system. In wide gap semiconductor the occupation should not change upon correction. In other system it can make the difference.
Anyway yambo should takes into account the new Fermi level if the energies are read for the QP database (KfnQPdb="E < SAVE/ndb.QP", please check the report file.
If not you can do that by using the following input variable"

Code: Select all

GfnQPdb= "E < SAVE/ndb.QP"

Best,
Daniele

[zsjan]

Thank you!
So does it indicate that the yambo can recalculate the Fermi level and according occupations if the energies are read for the QP database (KfnQPdb="E < SAVE/ndb.QP"?

[Daniele Varsano]

It should,
Now I'm not totally sure, check in the report, it should be written, otherwise you can use the variable I reported in the previous post.
Daniele