GW+BSE

[Reza_Reza]

Dear Daniele,

1) I am trying to redo the BSE calculation. Is it necessary to perform the BSE first with scissors and then with consideration of GW-corrected (QP), or is it possible to directly compute the BSE with QP?

2) My second ambiguity is that in my calculation with the same processors and RAM, the BSE calculation with GW correction is done, but without GW, it crashed.

3) Is it essential to consider the Coulomb truncation in the BSE calculation since, using the tutorial and using $ yambo -o b -k sex -F 02_3D_BSE_kernel.in -J 3D_BSE for the kernel and $ yambo -F 03_3D_BSE_diago_solver.in -y d -V qp -J 3D_BSE for diagonalization, the Coulomb truncation is not included in the input files?(I included it manually.)

For your review, I have attached my input and report files.

Best,

Reza

[Daniele Varsano]

Dear Reza,

1) Scissor or GW corrected energy are two alternative ways to take account quasiparticle energies, so you choose also depending on if a scissor approximation do applies or not.

2) It is not clear from your report exactly where it crashes, you should report the error message, but it seems an I/O error, you can try to remove the ./3D_BSE//ndb.dipoles file and repeat the calculations. Note also in the report several warning indicating you are using file generated by a different SAVE directory: this can be dangerous. Also, the parallelization between the two calculations seems different.

3) If you have a low dimensional system, coulomb truncation helps in converging with the vacuum. Adding the keyword "-r" activates it. In general by typing yambo -h you have a help on the command lines.

Best,
Daniele