Seeking Guidance on RPA and GWSE Calculations

[sc_han]

Dear respected forum users,

I would appreciate it if I could receive some assistance regarding using RPA and GWSE for energy generation.


After finishing the calculations utilizing ALGO = G0W0R, I am curious to know if it is correct to deduce that the difference between the 'eigenvalues' of the 'Energies using frozen KS orbitals' section and the 'Energies after update of density matrix' section in OUTCAR is the GWSE correction.

Furthermore, I am curious to know if the RPA + GWSE correlation can be acquired by adding the RPA correlation part to the same OUTCAR file and obtaining the energy difference through the abovementioned process.


Thank you for taking the time to read my post, and I look forward to your valuable response.

Best regards,

sc_han

[pedro_melo]

Dear sc_han,

If possible, can you provide the input files you are using? It would make it easier in answering your question if we can see what you are doing.

Kind regards,
Pedro Melo

[yao_zhao]

Dear sc_han and Pedro Melo,

I would be also interested in calculating single correction (either rSE or GWSE) to the RPA correlation energy, as described in theses papers:
https://www.nature.com/articles/s41467-018-07298-4
https://aip.scitation.org/doi/10.1063/1.4985878

So in order to calculate rSE, I need to somehow obtain “single-shot” Hartree-Fock energy. https://aip.scitation.org/doi/10.1063/1.4929346
I wonder if there is a way to print out HF matrix elements at the end of the exact energy calculation?
From the first paper, it's stated that

For the contribution of single excitations, we needed to optimize wavefunctions, which were determined by means of a blocked Davidson iteration scheme using up to 10 iterations per band.

But I am not quite sure how this is related to the single-shot HF energy.

Let me know if you found a correct way to calculate GWSE contribution as well.

BR,
Yao