Heiko, One comment on pseudopotentials. Usually pseudopotentials are not optimized for a particular problem. They are created to be good for any kind of problem. This is done by setting cutoff radii which yield the softest possible potential with good agreement of the pseudo-eigenenergies and logarithmic derivatives with the results of all-electron calculations for the isolated atom. The best you should do to "tune" a pseudopotential to some materials is to include core states in the valence (the so-called semicore states), or include nonlinear core corrections to account for the core electrons in an effective way, if you want to save computation time. In short, a "good" pseudopotential, once generated, should in principle be equally good in any kind of chemical environment.
What you actually optimize, in Siesta, are the basis sets. Those can be freely chosen to suit the kind of problem you are treating. For example, the basis set for a bulk calculation could turn out to be not so good for a surface calculation, which often involves quite extended states and could need more zetas for extra flexibility. The coherence between the functional used for the calculation and for the generation of the pseudo potential is, indeed, very important. Marcos On Mon, Oct 24, 2011 at 12:34 PM, Ahmed Huzayyin <[email protected]>wrote: > Dear BoXiao > > I also believe it is important to take into consideration relativistic > effects in Pt, may be someone with more experience on the group can verify > my claim. > > Best Regards > Ahmed > > Ahmed Huzayyin > Postdoctoral Research Fellow > ECE Department > University of Toronto > > ------------------------------ > *From:* Heiko Dumlich <[email protected]> > *To:* [email protected] > *Sent:* Monday, October 24, 2011 9:15 AM > *Subject:* Re: [SIESTA-L] pt.psf > > Dear BoXiao, > > you can not simply use any platin pseudo potential. You have to optimize it > for your problem. Further you have to be consistent with the functional and > flavor in the calculation and pseudo potential generation. Therefore I > suggest you use atom, which is provided with the siesta release to generate > your own pseudo potential. You can find the source files and > instructions,manual,tutorials in the folder siesta/Pseudo/atom/ > > Good Luck > and > Cheers > > Heiko > > > > On 10/24/11 14:52, BoXiao wrote: > > Dear users > > who could sent me the pt.psf file? many thanks! > > Best Wishes > > > -- > Heiko Dumlich > Freie Universität Berlin > Fachbereich Physik - AG Reich > Arnimallee 14 > D-14195 Berlin > GERMANY > > Phone: +49-30-838 56157 > > > >
