Linear stretching of the conduction bands

[kerensanni]

Dear All,


What could possible be the reason when the stretching on the conduction bands is not linear? What can be done to make this more linear? I added more unoccupied states, but still it is not linear.

Thanks

Jonah Nagura
University of Ibadan,
Nigeria.

[Daniele Varsano]

Dear Jonah,
it could be for many reasons, e.g. different character and localization of Bloch functions for different k points. In general, it can be a physical origin and not a matter of convergence. Anyway, I cannot say more as I do not know the details of the system you are studying. In this case, scissor+streching procedure could not be accurate and it is needed to calculate the GW correction for all the bands of interest.

Best,
Daniele