[Pw_forum] EXX

[Stefano de Gironcoli]

Hybrid functionals (currently only HF and PBE0) are kind of implemented 
in PWscf.
"Kind of" means under development, basically untested and unsupported 
(even less than other features).
It only works with NCPP and, since no HF or PBE0 pseudopotential 
generation in available, one needs to force the DFT from input using 
input_dft variable in system namelist. Forces are ok, stress are not.
It is VERY slow and I don't know if it will be possible to improve on that.

My suggestion is to wait sometime, until at least an example is provided.
If you still want to use it, be very carefull and report mis-behaviors 
to me (not to get a quick fix, but to help in the development)
In order to use it one should define -DEXX in DFLAGS in make.sys and 
recompile everything

stefano


Giovanni Cantele wrote:

> Dear all,
> as far I understand, implementation of hybrid functionals
> (exx.f90) is in progress within Quantum-ESPRESSO.
>
> Is it already possible to test it?
>
> If yes, I find in some parts of the code lines like
> #if defined (EXX)
> ...
> #endif
>
> So, should I both recompile the code with -DEXX option
> and add some specific variable in the input file?
>
> Thanks for help,
> Giovanni
>