Response Block Size

[adipopescu2000]

Hello,
I am a new Yambo user, and I am trying to run a GoWo quasiparticles correction. What is the meaning of the NGsBlkXp variable, response block size?
Thanks,

[Daniele Varsano]

Dear Adrian,
NGsBlkXp define the dimension of the inverse dielectric matrix \eps_GG' you need in the plasmon pole approximation to build up the screened Coulomb potential W_GG'.
You can have a look here or more in details Eqs.5 and the following equations in the yambo paper.
A. Marini et al. Comp. Phys. Comm. 180, 1392 (2009)

Best,

Daniele

[adipopescu2000]

Hi Daniele,

Thank you for your reply. So if I correctly understand, the response block size is bounded by the total number of bands of the system?

Best,
Adrian

[Daniele Varsano]

Dear Adrian,
no, the blocks are in G-space and are not related with the number of bands.
I invite you to follow the equation and convince yourself.
You have a sum over states (bands) in order to build the X^0 response function, but the G components are only limited to the plane wave cutoff.

Best,
Daniele