ERROR in[05] Coloumb potential CutOffslab

[sunxl]

Dear all,

When I calculated the BSE spectrum, I tested the BSEBands first, and when I changed the number of bands of the BSEBands, I found that sometimes there was an error and sometimes the calculation was complete. For example, when I choose 8 valence bands and 4 conduction bands (8v4c), I can normally get the output result, 9v4c, 10v4c can get the output result, but 8v5c, 10v6c, there will be the following error.

[ERROR] STOP signal received while in[05] Coloumb potential CutOffslab
[ERROR] Reading File ./10v6c//ndb.cutoff; Variable NOT DEFINED; NetCDF: Unknown file format

I appreciate any guidance and tutorial on that!

Best,
sunxl

[Daniele Varsano]

Dear Sunxl,

this probably happen because you calculated the coulomb potential for a certain number of components in a previous run and now for the BSE run you are using BSENGBlk=-1 (i.e. all the G components of the system).

I suggest you to set BSENGBlk to a reasonable cutoff, as you do not need to evaluate the direct kernel using all the components. BSENGBlk is a parameter that need to be converged, so start with e.g. 3Ry and then increase it gradually until convergence.

If the number of RL asked in BSENGBlk is larger than the one present in ndb.cutoff, you can delete the file and Yambo will recalculate it for the needed components.

Best,

Daniele