[Pw_forum] testing HSE for BCC Fe

[Paolo Giannozzi]

> The computational complexity of a calculation with hybrid functionals goes
> as (Nk*Nb)^2*Npw log(Npw) or so, where Nk=number of k-points, Nb=number of
> occupied bands, Npw=number of plane waves; with GGA functionals, as
> Nk*Nb*Npw log(Npw) or Nk*Nb*Npw^2
>

well, no, as Nk*Nb*Npw log(Npw) or Nk*Nb^2*Npw

Paolo

>
>
> could you try to explain me how to reduce the computation time
>>
>
> first of all you may try to reduce one of the sums over k-points using
> options nq1,nq2,nq3, as explained in the example for hybrid. For a metal,
> not sure it works well, though. Since you are using UltraSoft
> PseudoPotentials, try option "tqr=.true." (real-space treatment of
> augmentation functions): it should give a significant speedup. Another
> significant improvement is contained in the forthcoming 6.0 version of QE,
> but it doesn't work yet for USPP
>
> Paolo
> --
> Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
> Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
> Phone +39-0432-558216, fax +39-0432-558222
>
>


-- 
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20160909/2708dc3d/attachment.html>