Dear Marcos,
thank you for the comment. What I intended to say was, depending on the
problem you want to study, you will choose a certain functional (or
different functionals) for which you have to consistently generate your
pseudopotentials.
For sure pseudopotentials should in general be transferable. Therefore a
throughout testing on known problems should be performed prior to
calculation of new systems with the pseudopotential. (e.g. calculating
some properties of easy bulk platinum and comparison to other
theoretical results and experimental results)
Cheers
Heiko
On 10/24/11 16:55, Marcos Veríssimo Alves wrote:
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]
<mailto:[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]
<mailto:[email protected]>>
*To:* [email protected] <mailto:[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 <tel:%2B49-30-838%2056157>
--
Heiko Dumlich
Freie Universität Berlin
Fachbereich Physik - AG Reich
Arnimallee 14
D-14195 Berlin
GERMANY
Phone: +49-30-838 56157
