[QE-users] time consuming band structure calculation for a supercell

[Zahra Khatibi]

Dear all,

First of all, I hope everyone is safe and well in these crazy times.
I'm calculating the electronic band dispersion of a 2D heterostructure with
a 59 atom unit cell. This system is a small bandgap (10-20 meV)
semiconductor. The number of valence bands is (valence electrons/2) 181.
When I set 'nbnd' to 190, the band structure calculation costs me 30
minutes for each k point on HPC with 72 processors. This means that if I do
a simple band calculation for a high symmetry path with 100 points within,
I have to wait almost 50 hours! This even becomes worst when I try to
evaluate the band dispersion with SOC switched on (twice the spin
degenerate band calculation).
Since the band dispersion evaluation is the major part of our study, I was
wondering if there is a way around this problem, like reducing the number
of bands by only looking at energy interval close to Fermi energy?
I could see that there are lots of papers and studies in the literature
with huge unit cells and heavy atoms that have presented numerous band
structures (using QE). So I really appreciate it if you could help me here.

Kind regards,
--
Z. Khatibi
School of Physics
Trinity College Dublin
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20201211/be9333a6/attachment.html>