[Pw_forum] application of electric field to monolayer TMDC

[Thomas Brumme]

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
>
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum

-- 
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: Thomas.Brumme at mpsd.mpg.de

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20160509/10e9538f/attachment.html>