BSE: convergence vs. kpoints mesh
Posted: Sat May 18, 2013 6:01 pm
Hi,
I was using BSE to for calculating optical absorption spectra of a 2D material.
I see that convergence vs. kpoint is not that good. I get qualitatively similar spectra from k-point from 30x30x1 to higher, say 45x45. The only problem is the shift to lower energy (100 meV). I though 30x30 is quite dense mesh. The shift is fine (eventually it effects strongly on the binding energy of exciton), just want to have converged results.
Is it a common problem? Is there any setting to improve the way the code integrate over the BZ?
Thanks.
Duy
I was using BSE to for calculating optical absorption spectra of a 2D material.
I see that convergence vs. kpoint is not that good. I get qualitatively similar spectra from k-point from 30x30x1 to higher, say 45x45. The only problem is the shift to lower energy (100 meV). I though 30x30 is quite dense mesh. The shift is fine (eventually it effects strongly on the binding energy of exciton), just want to have converged results.
Is it a common problem? Is there any setting to improve the way the code integrate over the BZ?
Thanks.
Duy