Yambo Community Forum

Dear developers,

I use yambo_nl -u to generate a yambo.in file for nonlinear optical calculation. How can I set the number of NLBands?

In the example of AlAs, there are 4 orbitals occupied by electrons and 11 empty orbitals. In the yambo.in file, the NLBands values are 3 and 6, respectively. I am not sure how to set the band range values? Could you give me some hints? Thank you very much!


Best regards,
Davy Hou

Dear Davy Hou

in principle you should include bands close to the gap,
for example in the AlAs the gap is between the bands 4 and 5,
and therefore we include 2 valence and 2 conductions, namely from band 3 to 6.

You should test that this band range is enough to converge your non-linear response
in the energy range you are interested in.
For example you can repeat calculations with bands range 2-6, 1-6, 2-7, 2-8 etc... and see
if the result changes.
If it does not change it means that your results are converged respect to the bands range.

best
Claudio

Dear Dr. Claudio Attaccalite,

Thank you so much for your kind help. I will do the tests according to your advice.

Best regards,
Davy Hou