Yambo Community Forum

Dear developers,
I used -y d to solve the BSE, and the eps, eels, jdos and report were all good. I also found nbd.BS_diago_Q* files in the SAVE folder. However, when I used "ypp -e s -b 1 -J SAVE", I received the following error: What's going on? I also attach the report file of BSE solver.

Dear Huaiyuan Yang,

from the report you poster it seems that the ndb.BS_diago_Q* are stored in a directory named "bse".
Have you tried to run

ypp -e s -b 1 -J bse

Best,

Daniele

Dear Daniele,
Thanks for your reply. Actually, what I have run was "ypp -e s -b 1 -J bse". The ndb.BS_diago_Q* files are all in bse folder. There must be some other reasons.
Best,
Huaiyuan

Dear Huaiyuan,

the syntax you are using seems to be correct, please be sure you have the file ndb.BS_diago_Q1 in your bse folder and you are using the ypp from the release of yambo you calculated the database.

Best,
Daniele

Dear Daniele,
Thanks for your reply. The ndb.BS_diago_Q* files are actually in the bse folder and the ypp is installed together with Yambo 5.0.4.
This error is very confusing. I'll calculate the BSE again to see what will happen.
Best,
Huaiyuan

Dear Huaiyuan,
the problem you are facing is rather strange, and I have no idea to what it can be related, does it happen for all the Q you calculated (e.g. -b 18)?
If it is just a matter to look at the eigenvalues, this can be overcome by looking directly to the ndb.BS_diago_Q* file: these are written in netcdf format you can make them readable
by using the ncdump command. You can find in your machine if you have netcdf already compiled there, or in the lib directory of yambo (type find . -name ncdump inside yambo/lib if they have been compiled during the yambo installation). Just note that energies in the database are in Hartree and not in eV.

Anyway this does not solve the problem if you need to calculate other quantities extracted from the ndb.BS_diago_Q* databases e.g. excitonic wavefunction.

Best,

Daniele

Dear Daniele,
The error happens to all Q points. Luckily, what I cares most is the exciton energies, so I can use ncdump command to get the BS_Energies. Thanks for your valuable advice.
Best,
Huaiyuan

Dear developer,

I faced exactly the problem mentioned above for slepc solver. When I used "ypp -e s 1 -J ...." for bulk hBN,exciton energies were extracted correctly. But when I used ypp for my material, I received following error: Is there a way to solve this problem and extract the excitonic wavefunvtions from the ndb.BS-diago-Q database?
Given that this problem may be solvable using Yambo-4.5, is there a way to convert the ndb.BS-diago-Q database obtained from Yambo-5.0 to Yambo-4.5 without recalculation?
The report files for bulk hBN and my material are attached.

Thanks and Regards,
Mitra Helmi

Dear Mitra,

I assume that you are using the ypp and yambo coming from the same release (please check it!)

is there a way to convert the ndb.BS-diago-Q database obtained from Yambo-5.0 to Yambo-4.5 without recalculation?

Probably yes, but it could be not easy and the database have to be manipulated.
In the meanwhile, we try to spot what's the source of the error.

Best,
Daniele

Dear Daniele,

I assume that you are using the ypp and yambo coming from the same release (please check it!)

I did both the yambo and ypp calculations with Yambo-5.0.3 for both bulk hBN and my material.
I would be very grateful if you could help me to solve this problem.

Best,
Mitra