HSE06 vs GGA

[ams_nanolab]

Is HSE06 as good as GGA for energy calculations, structure optimization? I'm trying to simulate black Phosphorous and HSE06 (refernce papers) give different results in formation energy etc. than GGA.PBE.

MGGA-TB09LDA is not suited for energy / optimization thus I can't use that.

Which results are more trustworthy in this regard?

[Anders Blom]

HSE06 is typically more accurate. However, it's not only a matter of the exchange-correlation potential, you also need to consider the quality of the pseudopotential and basis set. For instance, if you use the FHI basis sets in ATK, you can try the HGH ones instead (with a higher density cut-off, as these pseudopotentials are "harder").

[Kim_W]

Can I use HSE06 to calculate the optical spectrum of materials?

[Ulrik G. Vej-Hansen]

No, it is unfortunately not implemented in ATK, but we are exploring it, so it might be added in the future.