RPA dielectric function
Moderators: Davide Sangalli, andrea.ferretti, myrta gruning, andrea marini, Daniele Varsano, Conor Hogan
-
- Posts: 12
- Joined: Tue Oct 04, 2011 9:52 am
RPA dielectric function
Dear Developers and Yambo user,
Is there a way to print the RPA dielectric function in Yambo?
In particular I'm interested in its q-dependence:
\epsilon_{G=0,G'=0}(q,\omega=0)
Is there an input variable that will write this information somewhere? If not, could you point me to the subroutine where I could add a print for this.
Thank you very much,
Best wishes,
Samuel
Is there a way to print the RPA dielectric function in Yambo?
In particular I'm interested in its q-dependence:
\epsilon_{G=0,G'=0}(q,\omega=0)
Is there an input variable that will write this information somewhere? If not, could you point me to the subroutine where I could add a print for this.
Thank you very much,
Best wishes,
Samuel
Samuel Poncé
Department of Materials, University of Oxford
Department of Materials, University of Oxford
- Daniele Varsano
- Posts: 3824
- Joined: Tue Mar 17, 2009 2:23 pm
- Contact:
Re: RPA dielectric function
Dear Samuel,
this can be done by using the yambo-py utility. Here there is an example on how to extract the data you are looking for:
http://www.yambo-code.org/wiki/index.ph ... ption_(BN)
in particular:
it is the function that do that.
Note that the ndb.em1s files do contains the response function vX_GG' and not the eps-1_GG' so a delta_GG' has to be added (I think that the python script do it! but may be it is worth to check).
Best,
Daniele
this can be done by using the yambo-py utility. Here there is an example on how to extract the data you are looking for:
http://www.yambo-code.org/wiki/index.ph ... ption_(BN)
in particular:
Code: Select all
>yambopy plotem1s PATH
Note that the ndb.em1s files do contains the response function vX_GG' and not the eps-1_GG' so a delta_GG' has to be added (I think that the python script do it! but may be it is worth to check).
Best,
Daniele
Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/
-
- Posts: 12
- Joined: Tue Oct 04, 2011 9:52 am
Re: RPA dielectric function
Dear Daniele,
Thank you very much for the quick reply.
I did not know about the python yambo ! Very nice. Super easy to install.
I'm doing GW calculations (not BSE). Yambo seems to not produce ndb.em1s files in that case.
I first though it was because I was doing dynamical screening ( em1d variable ).
Is there a way to extract it? Technically its just the \omega=0 part.
In any case, I have redone the calculation with em1s instead.
However, it seems Yambo is still not producing the file. I'm using Yambo v. 4.1.4
Am I missing any input variable to get that file?
Below is my input file (silicon):
Thank you very much for the quick reply.
I did not know about the python yambo ! Very nice. Super easy to install.
I'm doing GW calculations (not BSE). Yambo seems to not produce ndb.em1s files in that case.
I first though it was because I was doing dynamical screening ( em1d variable ).
Is there a way to extract it? Technically its just the \omega=0 part.
In any case, I have redone the calculation with em1s instead.
However, it seems Yambo is still not producing the file. I'm using Yambo v. 4.1.4
Am I missing any input variable to get that file?
Below is my input file (silicon):
Code: Select all
gw0 # [R GW] GoWo Quasiparticle energy levels
ppa # [R Xp] Plasmon Pole Approximation
em1s # [R Xd] Dynamical Inverse Dielectric Matrix
HF_and_locXC # [R XX] Hartree-Fock Self-energy and Vxc
X_all_q_CPU= "1.1.72" # [PARALLEL] CPUs for each role
X_all_q_ROLEs= "c.v.k" # [PARALLEL] CPUs roles (q,k,c,v)
X_all_q_nCPU_invert= 72 # [PARALLEL] CPUs for matrix inversion
SE_CPU= "1.72" # [PARALLEL] CPUs for each role
SE_ROLEs= "b.qp" # [PARALLEL] CPUs roles (q,qp,b)
EXXRLvcs= 15 Ry # [XX] Exchange RL components
Chimod= "Hartree" # [X] IP/Hartree/ALDA/LRC/BSfxc
% QpntsRXp
1 | 72 | # [Xp] Transferred momenta
%
% BndsRnXp
1 | 120 | # [Xp] Polarization function bands
%
NGsBlkXp= 2 Ry # [Xp] Response block size
% LongDrXp
1.000000 | 0.000000 | 0.000000 | # [Xp] [cc] Electric Field
%
PPAPntXp= 16.5 eV # [Xp] PPA imaginary energy
% GbndRnge
1 | 120 | # [GW] G[W] bands range
%
GDamping= 0.100000 eV # [GW] G[W] damping
dScStep= 0.100000 eV # [GW] Energy step to evalute Z factors
DysSolver= "n" # [GW] Dyson Equation solver (`n`,`s`,`g`)
%QPkrange # [GW] QP generalized Kpoint/Band indices
1| 72| 1| 20|
%
%QPerange # [GW] QP generalized Kpoint/Energy indices
1| 72| 0.0|-1.0|
%
Samuel Poncé
Department of Materials, University of Oxford
Department of Materials, University of Oxford
- Daniele Varsano
- Posts: 3824
- Joined: Tue Mar 17, 2009 2:23 pm
- Contact:
Re: RPA dielectric function
Dear Samuel,
Just drop the gw0,ppa and HF_ keyword at the beginning of the input file and leave the em1s runlevel.
Best,
Daniele
This is a nice work done by Henrique Miranda and Alejandro Molina-Sanchez.I did not know about the python yambo ! Very nice. Super easy to install.
Right as in GW you need dynamical screening.I'm doing GW calculations (not BSE). Yambo seems to not produce ndb.em1s files in that case.
It should be easy, you can try to modify the script in order to read the ndb.pp files and take the right component, I cannot help too much, can read an play with python but I'm not really proficient.s there a way to extract it? Technically its just the \omega=0 part.
As you have gw runlevel yambo still calculate the dynamical screening (pp) in this case.Am I missing any input variable to get that file?
Just drop the gw0,ppa and HF_ keyword at the beginning of the input file and leave the em1s runlevel.
Best,
Daniele
Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/
-
- Posts: 12
- Joined: Tue Oct 04, 2011 9:52 am
Re: RPA dielectric function
Dear Daniele,
Thank you for the additional info. By removing the keyword I was indeed able to get the ndb.em1s file.
Now, I have a bugreport for yambopy and a question:
1) bugreport
The python script yambopy does not seem to work with python 2.7
However, I was able to make it work by adding ".variables" to all calls to netcdf database in the module "yambopy/dbs/em1sdb.py"
This is actually the way I learned how to call netcdf database. Does it work without it in python 3 or something?
For example replacing:
by
make it works.
2) question
Doing those modifications gives me the em1s.dat file.
The values seems very reasonable and good !
Could you just tell me in what units are the q given ? The largest norm of q that is reported in the file is 0.10894892 in my case.
In my case I used the experimental lattice parameter of silicon (10.262 Bohr).
If I want to get the q in unit of 2pi/a, should I just multiply by 2pi? If so, then it seems the maximum value is 0.68 whereas it should actually be closer to 0.866. Does the code folds all the q into the 1st BZ and then report their q?
Thank you,
Best,
Samuel
Thank you for the additional info. By removing the keyword I was indeed able to get the ndb.em1s file.
Now, I have a bugreport for yambopy and a question:
1) bugreport
The python script yambopy does not seem to work with python 2.7
However, I was able to make it work by adding ".variables" to all calls to netcdf database in the module "yambopy/dbs/em1sdb.py"
This is actually the way I learned how to call netcdf database. Does it work without it in python 3 or something?
For example replacing:
Code: Select all
self.alat = database['LATTICE_PARAMETER'][:]
Code: Select all
self.alat = database.variables['LATTICE_PARAMETER'][:]
2) question
Doing those modifications gives me the em1s.dat file.
The values seems very reasonable and good !
Could you just tell me in what units are the q given ? The largest norm of q that is reported in the file is 0.10894892 in my case.
In my case I used the experimental lattice parameter of silicon (10.262 Bohr).
If I want to get the q in unit of 2pi/a, should I just multiply by 2pi? If so, then it seems the maximum value is 0.68 whereas it should actually be closer to 0.866. Does the code folds all the q into the 1st BZ and then report their q?
Thank you,
Best,
Samuel
Samuel Poncé
Department of Materials, University of Oxford
Department of Materials, University of Oxford
- Daniele Varsano
- Posts: 3824
- Joined: Tue Mar 17, 2009 2:23 pm
- Contact:
Re: RPA dielectric function
Dear Samuel,
for the first question you should address your question to the yambo-py subforum, Alejandro or Henrique can answer to your question.
You can check anyway in the report of yambo the q vectors in different units. If there is something not clear I suggest you again to write to the yambo-py subforum, as the developers will answer you.
Best,
Daniele
for the first question you should address your question to the yambo-py subforum, Alejandro or Henrique can answer to your question.
The q are in the Irreducible BZ, quickly looking into em1sdb.py, it seems that they are in unit of alat.Could you just tell me in what units are the q given ? The largest norm of q that is reported in the file is 0.10894892 in my case.
In my case I used the experimental lattice parameter of silicon (10.262 Bohr).
If I want to get the q in unit of 2pi/a, should I just multiply by 2pi? If so, then it seems the maximum value is 0.68 whereas it should actually be closer to 0.866. Does the code folds all the q into the 1st BZ and then report their q?
You can check anyway in the report of yambo the q vectors in different units. If there is something not clear I suggest you again to write to the yambo-py subforum, as the developers will answer you.
Best,
Daniele
Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/
-
- Posts: 12
- Joined: Tue Oct 04, 2011 9:52 am
Re: RPA dielectric function
Dear Daniele,
Thank you very much for your help.
I posted on the yambopy subforum as your recommended.
Best,
Samuel
Thank you very much for your help.
I posted on the yambopy subforum as your recommended.
Best,
Samuel
Samuel Poncé
Department of Materials, University of Oxford
Department of Materials, University of Oxford
-
- Posts: 86
- Joined: Thu Nov 26, 2020 2:56 pm
- Contact:
Re: RPA dielectric function
Dear team yambo,
can we calculate q-resolved dielectric function within RPA approximation in YAMBO for the calculation of plasmon dispersion? If yes, then how to set q-value?
Thanks,
Pushpendra
can we calculate q-resolved dielectric function within RPA approximation in YAMBO for the calculation of plasmon dispersion? If yes, then how to set q-value?
Thanks,
Pushpendra
Pushpendra Yadav
Ph.D. Research Scholar
Quantum Transport and Theory Group
Department of Physics
Indian Instittute of Technology Kanpur, India.
https://sites.google.com/site/amitkag1/
Ph.D. Research Scholar
Quantum Transport and Theory Group
Department of Physics
Indian Instittute of Technology Kanpur, India.
https://sites.google.com/site/amitkag1/
- Daniele Varsano
- Posts: 3824
- Joined: Tue Mar 17, 2009 2:23 pm
- Contact:
Re: RPA dielectric function
Dear Pushpendra,
yes you can do that by selecting the q index you want to calculate the response in the QpntsRXd namelist e.g.:
The q vectors corresponding to the index are shown in the report file:
Best,
Daniele
yes you can do that by selecting the q index you want to calculate the response in the QpntsRXd namelist e.g.:
Code: Select all
% QpntsRXd
1 | 14 | # [Xd] Transferred momenta
%
Code: Select all
...
K/Q-points units:
rlu = crystal or reduced units; cc = cartesian coordinates; iku = interal k-units
...
Daniele
Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/