hbn tutorial and the "Coulomb Cutoff"
Posted: Fri Jul 26, 2019 7:37 am
Dear all,
I have a probably stupid question: the hbn tutorial has a section about layer separation and Coulomb cutoff; I tried to converge the BSE spectra wrt. the layer distance but increasing the layer separation (I went up to 120 a.u.) still does not "converge" the BSE spectrum. As a matter of fact it looks like it is shifted by a constant just as I increase the layer separation.
Note that the dielectric converges around 65 a.u. layer separation.
Is there any reason why the gap keeps opening by increasing the layer separation or is this just a case of (most likely) underconverged BSE wrt. k-points etc?
Thanks for your help!
Chris
I have a probably stupid question: the hbn tutorial has a section about layer separation and Coulomb cutoff; I tried to converge the BSE spectra wrt. the layer distance but increasing the layer separation (I went up to 120 a.u.) still does not "converge" the BSE spectrum. As a matter of fact it looks like it is shifted by a constant just as I increase the layer separation.
Note that the dielectric converges around 65 a.u. layer separation.
Is there any reason why the gap keeps opening by increasing the layer separation or is this just a case of (most likely) underconverged BSE wrt. k-points etc?
Thanks for your help!
Chris