Yambo Community Forum

Hi, all
After running ABINIT with GGA PBE (xc function) I insert the KSS file to yambo code to calculate GW and BSE. I found yambo always use LDA Perdew & Wang (xc function). Does yambo support GGA ? However can we choose exchange-correlation function in yambo?

Thanks

Zhifan Chen
Dept of Physics
Clark Atlanta University
USA

Dear Zhifan Chen

At the moment Yambo dos not support GGAs.
The XC functional cannot be chosen:
When Yambo recognizes the XC functional in the DFT calculation, it automatically uses that XC functional.
When it does not recognize the XC functional, Yambo switches indeed to LDA Perdew & Wang.
Of course the mismatch between the XC functional in the DFT and in the YAMBO calculation introduces an error. In general this won't be big because the XC potentials (thus the KS wavefunction and energies) are similar but still it is better to have the same XC. Since you are calculating the GW corrections, and the QP energies should not depend on the 0 order, I would advise, if possible, to use LDA for your DFT calculations.

Regards,
Myrta