[Wien] experimental vs relaxed parameters using wien2k

[Tristan de Boer]

You can find many papers that use either approach. I considered this 
somewhat tangentially in a paper on several semiconductor polymorphs 
that were synthesized under different pressures. [1] We collected x-ray 
absorption and emission spectra on thee polymorphs, and compared our 
spectra to those calculated using the PBE GGA functional for both 
relaxed and unrelaxed atom positions. We found that there was worse 
agreement with experiment using relaxed parameters compared to the 
experimental parameters, so at least for this case, using the 
experimental structure yields more correct results. I'm not sure how 
universal this is, and it may not apply as you move higher up the 
'Jacob's ladder' of density functional approximations.
Best Regards,
Tristan

[1] doi:10.1103/PhysRevB.93.155205


On 2017-07-24 6:27 AM, Chouaib AHMANI FERDI wrote:
> Greatings Wien users,
>
> I just want to ask if the experimental parameters (lattice parameters,
> internal parameter, atomic positions, ...) are already available for a
> certain compound, would it be better to run SCF cycle with them or to
> make preliminary relaxation and volume optimization and then perform SCF
> cycle using the calculated parameters.
>
> Faithfully,
>
>
>
> --
> AHMANI FERDI Chouaïb
> Ph.D Student in Material Science
> Ecole Normale Supérieure
> Mohammed V University, Rabat.
> Tel : +212 6 94 59 57 60
>
>
>
>
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> SEARCH the MAILING-LIST at:  http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
>