Dear Ghadiyali Mohammed Kader,
the paper by Meyer and Vanderbilt does include a discussion about the
"dipole correction".
The whole story (why a dipole correction is needed) is actually a little
bit more involved and
not so important - you just need to know, that if you want to simulate a
system in an electric
field, you also need to switch on the dipole correction in most cases.
Irrelevant details:
- Neugebauer and Scheffler wanted to simulate the adsorption of Na and K
on Ag(111)
(paper: Phys. Rev. B 46, 16067 (1992))
- to compensate the dipole within the system (to be able to use a
3D-periodic boundary code)
they introduced an external electric field (the sawtooth potential)
- Bengtsson showed that in this case it is actually not "external" but
has an "internal" origin
and that's why you have to multiply it by a factor of 1/2
(paper: Phys. Rev. B 59, 12301 (1999))
- the paper by Meyer and Vanderbilt is more or less a summary of these
details, i.e., that
for the internal dipole (also the one induced by the external field)
you have a slightly different
equation (the prefactor and the internal dipole needs to be
recalculated each scf step as the
density changes)
- in VASP they actually don't cite the paper by Bengtsson but only state
that a more general
approach is chosen which does not include the mistake of the
Neugebauer/Scheffler paper
Regards
Thomas
On 08.01.2018 13:36, Mohammed Ghadiyali wrote:
Respected Sir,
Thank you for the inputs.
Can you suggest any paper/s where the dipole interaction is explained?
The paper by Meyer and Vanderbilt do not cover it.
Regards,
Ghadiyali Mohammed Kader,
Research Scholar,
Dept. of Physics,
University of Mumbai.
--
Dr. rer. nat. Thomas Brumme
Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry
Leipzig University
Phillipp-Rosenthal-Strasse 31
04103 Leipzig
Tel: +49 (0)341 97 36456
email: thomas.bru...@uni-leipzig.de
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