Convergence of k-point mesh

Please post here any issue related to convergence parameters in linear response GW and BSE calculations.

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Laura Caputo
Posts: 49
Joined: Sun Apr 11, 2021 3:02 pm

Convergence of k-point mesh

Post by Laura Caputo » Sun Jun 20, 2021 11:32 am

Good morning,

I am calculating the GW gap of some systems, which are quite big so calculations take a while also with parallelization. The convergence of k-point is thus quite difficult so I was reading some threads and I have the following questions:

1) The convergence of the k-point mesh should be independent of the convergence of bands etc. So, could it be done with lower parameters and not the converged ones in order to have faster results?

2) Could I calculate the GW gap with less dense meshes and then extrapolate the results in denser meshes?
Laura Caputo
Ph.D. Student
Université Catholique de Louvain

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Daniele Varsano
Posts: 2992
Joined: Tue Mar 17, 2009 2:23 pm

Re: Convergence of k-point mesh

Post by Daniele Varsano » Sun Jun 20, 2021 3:01 pm

Dear Laura,

the answer is yes to both your questions.
About extrapolation, of course the finer the grid you are ale to calculate the smaller will be the error of the extrapolation.

Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale

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