inizialization and databases

[claudio]

Dear Sam

put "--without-netcdf-lib --without-netcdf-include" in your configure.

A question, in which folder you run yambo? you should not run it in the SAVE folder but outside,
in the same folder where you run p2y

cla

[samazadi]

Dear Claudio

Thank you. I hope it works.
I know, I run yambo in the same folder where I run p2y

Cheers
Sam

[samazadi]

Dear developers and users,

I did GW calculations using plasmon pole approximation to fine quasi particle energy gap of system:
I have two questions:
1) in the report file there are two Gap parameters, Indirect Gap and Direct Gaps. What are they mean?
are they LDA Gap?
2) What are the columns 3,4 and 5 in o.qp ? One of them is quasi particle energies, what about two others ?

Cheers
Sam

[Daniele Varsano]

Dear Sam,
direct and indirect gaps, you can find the definition:here.
About the o.qp output, you can see that there is an header:

Code: Select all

#  K-point    Band       Eo         E-Eo       Sc(Eo)

The different two columns are self-explaining, next you have that
Eo is the DFT energy, E-Eo, is the different between the quasiparticle energy
and the Kohn Sham Energy, and finally Sc is the correlation part of the self energy
evaluated in Eo.

Hope it helps,
Cheers,

Daniele

[samazadi]

Dear Daniele

Thanks for your help. I know what is the physics meaning of Indirect and Direct Gaps.
My question was that these two parameters in the report file are DFT (Kohn-Sham) gaps
or qusi-particle gap? It seems they are DFT gaps, right ?

Cheers
Sam

[Daniele Varsano]

Dear Sam,

yes , in the report they are the KS gaps, you can realize that, this value is reported
after reading the KS electronic structure form the KS database. In the GW output you find
the quasiparticle corrections, and you can evaluate the new GW corrected gaps.
Note that in the report you find also information on the exchange part of the self-energy,
the renormalization factor and other amenities, that are somehow important for checking your
convergences.

Cheers,

Daniele

[samazadi]

Dear Daniele

By plotting E-Eo .vs. Band of o.qp file, my system shows a gap between highest occupied band (#electrons/2)
and lowest unoccupied band. But there is no gap in the E-Eo .vs. K-point plot.
I'm wondering is it right ?!

Cheers
Sam

[Daniele Varsano]

Dear Sam,
you can look at your QP band structure summing the third column (Eo) and the 4th (E-Eo).
In order to have a band picture you can easily handle your o.qp file in order to have

#Kpts E_band1 E_band2 E_band3

and plotting the different columns.

but I do not know if I have well understood your question.
Hope anyway it helps,

Daniele

[samazadi]

Dear Daniele

Is it possible to use hybrid-functional orbitals (e.g PBE0) as input of p2y ?
Actually I did it without any problem.
But PBE0-nscf calculations is impossible, so I put large number of unoccupied
bands in scf.input and also collect wave functions. of course enough number of k-points.

Cheers
Sam

[andrea marini]

Is it possible to use hybrid-functional orbitals (e.g PBE0) as input of p2y ?

Hybrid functionals are currently not supported. I think we introduced a sort of stop in the latest version of the code. What version are you using ?

In any case be carefull because those potentials are not supported.

Andrea