BSE convergence vs. k points

[sdwang]

Dear developers,
Considering the relative heavy calculations of BSE about the convergence of the k-point sampling, could we firstly converge the absorption spectrum of IPA w.r.t the k points, and then take the converged k points to obtain the final BSE spectrum?

Thanks!

Shudong

[Daniele Varsano]

Dear Shudong,

you can do a preliminary convergence test at IP level, but next a careful check on the BSE solution is needed as the number of k points needed to converge the excited state (exciton) depends on its nature (e.g. if it is formed by electron-hole pairs belonging to flat or highly dispersive bands).

Best,

Daniele