Hello
it seems fine; you are almost at convergence.
If I understand your doubt, you are confusing with the convergence in
cut-off energy.
At variance with convergence for the plane wave basis set, the
convergence in the k-points mesh is not "variational". It is not that a
denser mesh has to give you a lower or equal value of the energy, you
are just removing erroneous contribution to the sum in the Brillouin
zone coming from oscillating terms of shorter and shorter periodicity.
Removing more terms should eventually give you a more precise estimate
of the integral.
What you have to minimize is the difference of the energy at a certain
mesh density with the ones obtained using denser meshes, an that
difference in your case is indeed decreasing
I hope it helps.
regards
Pietro
On 01/10/20 07:20, Anupriya Nyayban wrote:
Dear experts/users,
I was trying to check the convergence for an orthorohmbic system and
got ecut convergence for 70. Later, I choose a smaller ecut of 40 for
testing kmesh convergence to reduce the computation time. But, I
observed a opposite pattern of convergence graph which is attached
below. Please suggest me what could be the possible reason! ( I choose
the key 'K_POINTS (automatic)' as ' $CUTOFF $CUTOFF $CUTOFF 1 1 1',
where CUTOFF value varies from 3 to 7.)
Any kind suggestions will be helpful for me.
Thank you
With regards
Anupriya Nyayban
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_______________________________________________
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list [email protected]
https://lists.quantum-espresso.org/mailman/listinfo/users
