Dear Sohail Ahmad,
you need to use them in all your calculations if you want to study the
effect
on the band structure... The relaxation and all calculation you do
afterward.
You can of course do a quick test calculation without relaxation but for
higher
fields the forces can be quite large - thus a relaxation is needed.
Furthermore, if you want to simulate the E field by applying a sawtooth
potential you need to switch on the dipole correction! dipfield=.true.
Read the description in INPUT_PW.txt and also the cited paper by L.
Bengtsson
PRB 59, 12301 (1999)
http://journals.aps.org/prb/abstract/10.1103/PhysRevB.59.12301
Another good paper on this subject with nice figures explaining everything:
PRB 63, 205426 (2001)
http://journals.aps.org/prb/abstract/10.1103/PhysRevB.63.205426
Regards
Thomas
On 05/07/2016 10:03 PM, Sohail Ahmad wrote:
Dear QE user
I wish to study band gap variation after applying electric field on a
monolayer of TMDC (Lets say MoS2)
My question is .......when should i use these
edir = 3, emaxpos = 0.5d0, eopreg = 0.1d0, eamp = 0.001,tefield = .true.
*
*
*Do i need to relax by using these parameters, and then use scf,nscf
as usual (without these) OR
*
*Use these paprameters directly in scf (without relax) and then
proceed as usual.*
Which one of the above mentioned is correct ?
Anxiously Waiting for comments
Best Wishes
-----------------------------------------------------------------------------------------------------------------
Sohail Ahmad
King Khalid University
Abha, Saudi Arabia
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Dr. rer. nat. Thomas Brumme
Max Planck Institute for the Structure and Dynamics of Matter
Luruper Chaussee 149
22761 Hamburg
Tel: +49 (0)40 8998 6557
email: [email protected]
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