Dear Christoph,
which version of QE are you using? Was it compiled with the old XML
format or the new one?
The new XML format had a bug in the way the input related to the dipole
correction was saved.
This was solved about a month ago:
https://gitlab.com/QEF/q-e/commit/81a946e15b80972f629c88e47e2545596350f31c
see also the related issue (closed)
https://gitlab.com/QEF/q-e/issues/5
Maybe your problem is due to this. If you use 6.2.1 either download the
develop branch or
compile using the old XML implementation.
Regards
Thomas
On 18.05.2018 12:50, Christoph Wolf wrote:
Dear all,
I am (again...) fighting with the dipole correction. I have a system
consisting of Ag and MgO centered in the cell around z=0.5
ATOMIC_POSITIONS (crystal)
Ag 0.000000000 0.000000000 0.323271580
Ag 0.000000000 0.500000000 0.385512833
....
Mg -0.000000000 0.000000000 0.721978968
O 0.500000000 0.000000000 0.723372273
O -0.000000000 0.500000000 0.723371161
Mg 0.500000000 0.500000000 0.721975961
Then I apply tefield and dipfield with
eamp = 0.00
edir = 3
emaxpos = 0.95
eopreg = 0.10
which means my system has no discontinuity anywhere in the slab and
the field is "physical" between 0.95+0.1-1=0.05 and 0.95 of the z
direction.
The SCF cycle converges but the pot_num=11 never becomes horizontal,
rather it has a very small slope. I tried to increase the dipole
length to see if that makes a difference but apparently it does not
help either. With above input the potential amplitude at scf
convergence is
Adding external electric field
Computed dipole along edir(3) :
Elec. dipole 0.4894 Ry au, 1.2440 Debye
Ion. dipole 0.4902 Ry au, 1.2460 Debye
Dipole 0.2274 Ry au, 0.5779 Debye
Dipole field 0.0008 Ry au,
Potential amp. -0.0855 Ry
Total length 55.5874 bohr
Is there a scenario where the dipole correction could fail if the
potential is "almost flat" in the vacuum region? If I run the same
with VASP I get a small "jump" in the potential making it flat in the
vacuum region, so I was wondering why this does not happen (probably
different approach in PWSCF)?
Input and resulting potential is attached - any help is welcome!
Thanks in advance and with best wishes,
Chris
--
Postdoctoral Researcher
Center for Quantum Nanoscience, Institute for Basic Science
Ewha Womans University, Seoul, South Korea
_______________________________________________
users mailing list
users@lists.quantum-espresso.org
https://lists.quantum-espresso.org/mailman/listinfo/users
--
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
_______________________________________________
users mailing list
users@lists.quantum-espresso.org
https://lists.quantum-espresso.org/mailman/listinfo/users
