[r,Vnl] included : yes

Deals with issues related to computation of optical spectra in reciprocal space: RPA, TDDFT, local field effects.

Moderators: Davide Sangalli, andrea.ferretti, myrta gruning, andrea marini, Daniele Varsano, Conor Hogan

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sdwang
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Joined: Fri Apr 09, 2010 12:30 pm

[r,Vnl] included : yes

Post by sdwang » Sat Apr 02, 2011 8:25 am

Dear developers:
I am confused about the parameter [r,Vnl] included : yes in the BSE calculation. What does it relate to, and how can I set it in inpuit file.I found in my output, it is "no".
Thanks!
S.D. Wang
S. D. Wang
IMU,HOHHOT,CHINA
E-mail: sdwang@imu.edu.cn

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Daniele Varsano
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Re: [r,Vnl] included : yes

Post by Daniele Varsano » Sat Apr 02, 2011 9:00 am

Dear Shudong,
this is the commutator with the no local part of the hamiltonian with the position.
In line of principle it should be included, but for practical reason, in this moment
Yambo includes it if you start from an Abinit calculation and it does not from
a pwscf (qe) calculation. It turns out, anyway, that in many cases omitting that term the error
is negligible, but of course is something that is system dependent.
As far as I know, Conor Hogan is working on that, and very soon,it
will be included also for pwscf ground state. At this moment may be it is working,
may be Conor can say you something more about the state of the development.

Cheers,

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/

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Conor Hogan
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Re: [r,Vnl] included : yes

Post by Conor Hogan » Wed Apr 06, 2011 11:30 am

Dear Shudong,
Indeed yes, the calculation of [r,Vnl] for PWscf will be included soon (within a few weeks), it just needs some more testing.
Conor
Dr. Conor Hogan
CNR-ISM, via Fosso del Cavaliere, 00133 Roma, Italy;
Department of Physics and European Theoretical Spectroscopy Facility (ETSF),
University of Rome "Tor Vergata".

soh
Posts: 4
Joined: Wed Nov 14, 2012 1:33 pm

Re: [r,Vnl] included : yes

Post by soh » Wed Dec 05, 2012 3:41 pm

Dear developers,

Am I correct in saying that [r,Vnl] is still not included if you start from a pwscf calculation? Or is there some tag that is required with p2y?

Thanks,
Siobhan O Halloran

Siobhan O Halloran
Phd Student
Materials Theory Group
Tyndall National Insitute
Cork
Ireland
siobhan.ohalloran@tyndall.ie

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Daniele Varsano
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Re: [r,Vnl] included : yes

Post by Daniele Varsano » Wed Dec 05, 2012 4:29 pm

Dear Siobhan O Halloran,
the non local part of the pseudopotential hould have been implemented,
and it is read from the pwscf elecgtronic structure when p2y is used with the "-c".
Unfortunately I do not know if it has been carefully tested.
Some times ago I noticed that the conversion is somehow slow, but I think that now should
work in parallel and it will speed up the conversion.
Try to browse the forum if there are more info.

Cheers,

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/

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