band index in the computation of \Chi_0

[caowd]

Dear all

I am reading the source code of yambo 4.0.1 and the file X_os.F in src/pol_funcion/ seems to calculate the \Chi_0.

In the file X_os.F, there are the following codes:
-------------------------------------------------------------------------------------------
loop_bare_grid: do i_bg = 1,bare_grid_N(i_cg)
!
n_poles=n_poles+1
!
! Scattering geometry
!---------------------
!
ikbz = X_poles_tab(n_poles,1)
iv = X_poles_tab(n_poles,2)
ic = X_poles_tab(n_poles,3)
i_spin = X_poles_tab(n_poles,4)
--------------------------------------------------------------------------------------------

My question is that whether the two variables (iv and ic) correspond to the band index in the summation in the computation of \Chi_0.
And the occupation for iv/ic is full/empty.

Could anyone please help me on this?

[Daniele Varsano]

Dear Wei-Dong Cao,
If presume you mean X_os_residuals.F.
Yes, as you argued iv is the index of the valence bands hence occupied and ic indicate the conduction bands.
They are used for the computation of Xo.

Best,

Daniele

[caowd]

Dear Daniele Varsano

Thank you for your quick response.
Yes, I means the file X_os_residuals.F in the latest version of yambo (4.0.2 rev.90) and it really helps me a lot.

Best Wishes.