Finite q BSE

[Zafer Kandemir]

Dear Developers,

I am trying to run BSE calculation, but I get the following error:
[ERROR] Finite q bse with spinors works only without symmetries. Use ypp to generate SAVE without symmetries.

Best regards.

[Daniele Varsano]

Dear Zafer,

the error message is telling you how to proceed:
1) Remove symmetries by using ypp (ypp -h for help)
2) Then you can do finite-q BSE calculations on the generate SAVE directory.

Of course the calculation without symmetries it is heavier, we have implemented the possibility to perform calculations exploiting symmetries but it is in phase of testing and it will be released soon.

Best,
Daniele

[Zafer Kandemir]

Dear Daniele,

Thank you for your reply.
I performed a similar calculation for a Janus TMDC (with SOC only, Not Magnetic) with version 5.0.0 without error. However, for similar materials version, 5.0.4 gives the mentioned error. Is the implementation in version 5.0.0 not correct?

Best regards.

[Daniele Varsano]

Dear Zafer,

Is the implementation in version 5.0.0 not correct?

Indeed, we realized that in presence of SOC the previous implementation of finite-q bse may have some problems when symmetries are taken into account.
You should check the exciton dispersion and see if the results are reasonable. Maybe a check without symmetry would be safe.
In any case, this problem seems to be solved and a new implementation it will be included very soon with the next release.
Best,
Daniele

[Zafer Kandemir]

Dear Daniele,

Thank you very much for your replies.

Best regards.

[Zafer Kandemir]

Dear Daniele,

In any case, this problem seems to be solved and a new implementation it will be included very soon with the next release.

When will the new version of Yambo you mentioned be released?

Best regards.

Zafer

[Daniele Varsano]

Dear Zafer,

probably in the next months with the new release, but I cannot yet tell you a date.
In the meantime you can try to perform calculations without the use of the symmetries.

Best,
Daniele