[QE-users] My slab system does not converge during optimization.Can you help me?

[Jayfe Anthony Abrea]

Hello Dr. Thomas,

[I am still adjusting with this QE mailing list. Thus, I made duplicate reply. Please bear with me Dr. Thomas]

I’m glad that you took notice on my predicament. Thank you Dr. Thomas. My appreciations.

The input file I placed in this email contains my initial positions of the atoms. The initial distance between H and surface is actually that “bad” or that far. I used the optimized positions of the slab with Fe instead of Mn and applied it to my Pt/Mn slab in the hopes that the atomic positions are closer to optimization. The z atomic position of H went down from 0.618734 to 0.607984. It still gave a similar oscillating result. =(

As for the applied external electric field, I’ve read that eamp, along with edir, emaxpos, and eopreg are adjusted for dipole correction of my slab system. I am not sure if making eamp to zero can still provide dipole correction. Will it still be OK to make it zero?

Best regards,

Jayfe


Sent from Mail for Windows 10

From: Thomas Brumme
Sent: Friday, April 16, 2021 4:03 PM
To: Quantum ESPRESSO users Forum; Jayfe Anthony Abrea
Subject: Re: [QE-users] My slab system does not converge during optimization.Can you help me?

Hi Jayfe,
Maybe the initial distance between hydrogen and the surface is just "bad"? Maybe reduce it a bit and see if this helps.
Another thing I noticed:
Do you really want an external electric field? Because the eamp is nonzero...
Regards
Thomas
On 4/15/21 4:05 PM, Jayfe Anthony Abrea wrote:
Hello fellow QE users and developers, 

I am new to Quantum Espresso and I am doing calculations on adsorption energy. I am using BURAI 1.3 GUI to aid in my QE setup thus I am not sure of the QE version that I am using. I am trying to do optimization on the hydrogen atom on the bimetallic slab (see attached input file). I have already employed several tweakings since the calculations never converged, such as:

- changed the mixing_mode to local-TF since it is suited for inhomogeneous system like my slab system
- lowering the mixing_beta to 0.1
- changing the ecutrho, ecutwfc, and starting_magnetization to the ones recommended by this website: http://www.materialscloud.org/work/tools/qeinputgenerator

These tweakings are made based on what I have read so far in this forum. After calculations, the slab-adsorbate system didn't achieve convergence in optimization (as seen in attached pics on SCF and accuracy). Manganese in my system seems to be problematic since when I tried replacing Mn with other metals (e.g. Fe and Co in particular), it reaches convergence and becomes optimized. I don't know now how to resolve this issue. I am hoping that you have great insights to address my plight.

I would really appreciate your help in this regard. Thank you!

Cheers,

Jayfe Anthony
Student
University of San Carlos


_______________________________________________
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list users at lists.quantum-espresso.org
https://lists.quantum-espresso.org/mailman/listinfo/users
-- 
Dr. rer. nat. Thomas Brumme
Theoretical chemistry
TU Dresden - BAR / II49
Helmholtzstr. 18
01069 Dresden

Tel:  +49 (0)351 463 40844

email: thomas.brumme at tu-dresden.de

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20210416/b056481e/attachment.html>