GW on Hartree Fock;

[Zahra Taghipour]

Dear Yambo developers/users,

I was wondering if it is possible to do GW calculations on top of Hartree-Fock(HF) in Yambo.
Is there a way to get HF energies/states in Yambo? I tried to get those from QE, but it takes forever.

Any comments would be highly appreciated.

Zahra Taghipour
PhD student in Optical Science and Engineering, UNM, USA

[Daniele Varsano]

Dear Zahara,

I was wondering if it is possible to do GW calculations on top of Hartree-Fock(HF) in Yambo.

In principle yes, bit we need to fix some detail in the p2y interface. In particular it happen that that the QE wfs were not recognized as HF wave functions butt Hartree only. In this case you should discard the Sigma_x contribution of the Self-Energy as already contained in the HF eigenvalues and calculate the QP energy by hand from the results of the Sigma_c. Moreover the commutator with the non local part of the Hamiltonian in not included in the calculation of the dipoles. We need to fix it!!
Should instead work for hybrid functionals even if not extensively tested.

Is there a way to get HF energies/states in Yambo? I tried to get those from QE, but it takes forever.

Unfortunately not in the GPL release, hopefully the self consistency needed to have HF energies (and Self consistent GW) will be released soon. In any case have you tried to use the new release of QE (6.0)? As far as I know the hybrid and HF part has been highly improved.

Of course with yambo you can calculate HF corrections to the DFT eigenvalues, which anyway differ form a real self-consistent HF calculation.

Best,
Daniele