Hi Daniele

Thanks for your kind reply.

I am going through the tutorials. But I am unclear about the following points:

1) When we calculated the QP energy with the single-shot G0W0 approxmation, we need to do the test of convergence with respect to

K-point, EXXRLvcs, BndsRnXs, and NGsBlkXs.

But when we turn to the optical properties within the regime of Bethe-Salpeter equation, do we need to test the convergence again, regarding the variables of [05] and [06] steps (i.e., BSEBands) in this tutorials

http://www.yambo-code.org/tutorials/fan ... ns/LiF.php 2) I am interested in the GW band structure. From tutorial 1, I know that the QP energy correction at every k point and corresponding bands can be extracted with respect to the LDA energy, i.e.

# K-point Band Eo E-Eo Sc(Eo)

1.00000 1.00000 -12.07289 -1.45848 4.03804

1.000000 2.000000 0.000000 0.663829 2.859195

1.000000 3.000000 0.000000 0.663829 2.859195

At here E-E0 is the QP energy correction, this value will be further used for the calculation of BSE (obtained the optical spectrum), right? This is analogous to the scissor operator approach (by setting the XfnQP_E variable), and in yambo we can only implement this technology to open the LDA gap or shift the onset of the absorption peak?

3) The exciton binding energy is defined by QP band gap (Eq) minus the optical band gap (Eo). Here Eq is the direct or indirect band gap after GW correction? Eo is the energy of the lowest energy absorption or strongest absorption peak?

I am sorry I have so many stupid questions. I have these questions after I tried the examples in the tutorials and went through the Yambo form. Your answer will help me get the correct results with the usage of YAMBO code.

thanks in adavnce

Best