[QE-users] [SPAM] Assistance with Convergence Issues of Surface Calculations

[Vinay Maithani]

Dear Quantum ESPRESSO community,

I hope this email finds you well.

I am currently working on large band gap semiconductors and have
encountered persistent difficulties in achieving convergence while
calculating the surface properties of these materials. Below are the
strategies I have attempted so far:

   - *Mixing Beta:* Adjusted up to 0.1
   - *Mixdim:* Increased to 24
   - *Smearing:* Gaussian with degauss = 0.2
   - *Nbnd:* Added a minimum of 20% more than the number of Kohn-Sham states
   - *Ecutwfc:* Increased from 50 Ry to 70 Ry
   - *Ecutrho:* Set to 8 times Ecutwfc
   - *Electron Max Step:* Extended to 2000 steps

Despite these efforts, my calculations still fail to converge, returning
the error:
*“Convergence NOT achieved after *** iterations: stopping.”*

I am using norm-conserving pseudopotentials and have applied dipole
corrections, but the issue persists. I have attached the input and output
files, along with the plot of potential data obtained via pp.x
(plot_num=11) and averaged in the xy-plane where a discontinuity occurs in
the vacuum region, available here: Google Drive link
<https://drive.google.com/drive/folders/1HoSFk11TMN4qAo8jZoSvyEymK92xGu2r?usp=drive_link>
.

I would greatly appreciate any insights or suggestions you may have to help
resolve this problem.

Thank you for your time and guidance.

Best regards,
Vinay Maithani
PhD Candidate, IIT Kharagpur
vinaymaithani21 at kgpian.iitkgp.ac.in
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