Yambo Community Forum

Dear all,

I'm just wondering if there is any way to visualize molecular orbitals corrected by COHSEX calculations?

Thanks in advance.

Best,
Reza

Dear Reza,
in the GPL release COHSEX calculation it is not implemented self consistently.
This means that COHSEC correction applies to the energies but not to the wave functions (molecular orbitals), which implies the assumptions that COHSEX orbitals are the same of KS orbitals.
We have implemented Self consistent COHSEX, but it is not yet released under GPL, and hopefully it will be done soon.

Best,
Daniele

Dear Daneile,

Thank you so much for your reply. The reason that I want to visualize my molecular orbitals is determining their localization. I saw in the literature that people use a factor named inverse participation ratio (IPR) to determine the localization without visualizing the molecular orbitals. I want to have that factor for the energy states in my dos plot (attached file) especially close to the band gap. The definition of that factor is very straight forward and has been brought in the attached paper page 2, right column, sixth line. Do you think if there is any way to extract the required information for calculating IPR from COHSEX calculation?

Like always thank you so much for your help and comments.

Best,
Reza

Dear Reza,
unfortunately I could not find the attached paper. If you want you can just post the reference.
Best
Daniele

Dear Daneile,

Here is the reference:

Dong, Jianjun, and D. A. Drabold. "Atomistic structure of band-tail states in amorphous silicon." Physical review letters 80.9 (1998): 1928.

Many thanks for your help.

Best,
Reza

Dear Reza,
the IPR factor looks me something related to the tight binding description of the Hamiltonian. Yambo relies on plane waves (as computed by quantum espresso) so it is not clear to me how to translate this IPR concept in plane wave basis set. Anyway as non self-consistent cohsex does not change the wave functions and they are exactly the same as computed by espresso, you can have a look tot he qe mailing list if something similar has been discussed.
Best,
Daniele

Dear Daniel,

Thank you for your comment. It was helpful.

Best,
Reza

Dear Dr. Daniele Sangalli,

Is the self-consistent COHSEX available in Yambo now?

Regards,
Kshirsagar Aseem Rajan,
PhD Student, CNRS,
Laboratoire de Science et Ingénierie des Matériaux et Procédés (SIMaP),
Grenoble-INP, Univ. of Grenoble-Alpes (UGA),
France-38042

Dear Kshirsagar Aseem Rajan,

unfortunately, the self-consistency on wave functions is not yet released. We really hope to release soon together with many other features.

Best,
Daniele

Okay. That would be very helpful. Thanks!

Regards,
aseem