Yambo Community Forum

Dear Daniele,

I did the GW band structure calculation using Yambo 4.5.1. Now that I want to do the BSE calculation with Yambo 5.0.3, it cannot read the ndb.QP database and the calculation stops with the following error:
<

---> P1: [WARNING]Wrong serial number for ./GW-all-BZ-kpoint21.out/ndb.QP
P1: [ERROR] STOP signal received while in[06] External/Internal QP corrections
P1: [ERROR] Reading File ./GW-all-BZ-kpoint21.out/ndb.QP; Variable PARS; NetCDF: Index exceeds dimension bound

Is there a way to calculate BSE with Yambo 5.0.3 using the ndb.QP database obtained from Yambo 4.5.1 or do I have to calculate GW band structure again with Yambo 5.0.3?

Thanks and Regards,
Mitra Helmi

Dear Mitra,
in principle, you could read the ndb.QP database using the ncdump command, and then generate a database using the ypp utility.
Anyway, if the calculation is not too heavy I suggest you to repeat the GW calculation with the updated code.
Best,
Daniele

Dear Daniele,

Is it possible to use the ndb.QP database obtained from a GW calculation for a BSE calculation with a lower k point grid, for example, the output of a GW calculation with 21*21*1 grid for a BSE calculation with 15*15*1 grid?

Thanks and Regards,
Mitra

Dear Mitra,

Unfortunately, it is not possible, as the two grids are different.
What you can do is an interpolation of the QPs in the larger grid and generate by hand a QP database for the smaller grid using ypp, but probably it is easier to calculate the QP correction for the new grid, or if possible, use a scissor/stretching operator with parameters extracted from the QP you
have already calculated.
Best,
Daniele