[QE-users] actual ecutwfc for Uranium PAW pseudo is way greater than recommended

[Sudip Kumar Mondal]

Hi all,
I am currently running an optimization of a Uranium bearing phase. The
pseudo in use for it is a scalar relativistic gga-PAW one generated by
Andrea dal Corso as available in QE website. I did try to check the
convergence of energy with respect to ecutwfc. Although the recommended cut
off is 103 Ry , the convergence is being achieved at 350 Ry i.e. almost 3.5
times of the recommended. However as typical of gga  , the lattice
parameters are overestimated by only by a very very small amount and are in
good agreement with other studies.
I know that the cutoff varies from system to system but the variations are
themselves small , as compared to what I have obtained.
Any suggestions on why the cutoff is so high are earnestly sought.
QE version : 5.4.0.
Thank you in anticipation.


--
Sudip Kumar Mondal
DST-INSPIRE Junior Research Fellow
High Pressure Temperature Laboratory
Dept. Of Physics/Geological Sciences
Jadavpur University
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