How to iterate the wave function when calculating GW

[Quxiao]

Dear Daniele:
Recently,I have new a new question after I read some paper about the GW calculation.Generally speaking, when we calculate the GW, we use KS state to approximate and replace the wave function, which does not cause great difference. However, when we study special problems, I saw that yambo introduced the iteration of eigenvalue when calculating GW, but how to make the eigenvalue and wave function iterate when calculating GW. The main reason is that I haven't found a method to calculate the iterative wave function of GW, which is what I am confused about at present. Could you give me some help？
Best wishes
Quxiao

[Daniele Varsano]

Dear Quixiao,

when you calculate the self-energy self-consistently, the easiest way is the eigenvalue only self-consistency. This can be done by iterating both G and W or G only as explained here:
https://www.yambo-code.eu/wiki/index.ph ... alues_only

In this case, as you can easily understand the wfs are not changed, ie KS wfs are used during all the procedures.

If you want to perform a self-consistent calculation while also updating the wfs, you can do it at COHSEX level (not GW). This is done by using the yambo_sc executable. You can have a try, this feature anyway has been released recently and has not been extensively documented.

Best,

Daniele