The empty bands

[sdwang]

Dear all:
How many the empty bands in pwscf input file should I have? If my unitcell include one B and one N atom, how many the empty bands they have?Or, this can only be decided through convergence test??
Thanks!

[Daniele Varsano]

Dear Sdwang,
as you presume, convergence tests are always needed. Moreover it strongly depend on the
quantity you want to calculate: GW corrections, absorption, etc...
As a suggestion, try to calculate a big number of empty bands, in order to make convergences tests,
adding bands with yambo input.

Cheers,

Daniele

[sdwang]

Dear Sdwang,
as you presume, convergence tests are always needed. Moreover it strongly depend on the
quantity you want to calculate: GW corrections, absorption, etc...
As a suggestion, try to calculate a big number of empty bands, in order to make convergences tests,
adding bands with yambo input.

Cheers,

Daniele

Do you mean adding the upper bands in BndsRnXp ?

[andrea marini]

Do you mean adding the upper bands in BndsRnXp ?

Yes, for example. That's the field the defines the bands range for the plasmon-pole response function. There are other variables in the inputs of Yambo related to the band range in e.g. the GW self-energy, the statically screened interaction, and so on. You should perform a PW run with enough bands to make possible to perform convergence tests.

Andrea