[CPMD-list] Pseudopotentials and diferences in results

[Juerg Hutter]

On Tue, 6 Apr 2004, Jim Kress wrote:

> Dear Dr. Hutter,
>
> Thank you for your reply.
>
> Should I also be using Kleinman-Bylander with the Goedecker
> pseudopotentials?

Goedecker pseudopotentials are already in a fully non-local form.
There's no need to do the Kleinman-Bylander transform.
In fact the keyword would be ignored by CPMD.

regards

Juerg Hutter


>
> Thanks for your help.
>
> Jim
>
>
> ----- Original Message -----
> From: "Juerg Hutter" <hutter at pci.unizh.ch>
> To: "Jim Kress" <cpmd at kressworks.com>
> Cc: <cpmd-list at cpmd.org>
> Sent: Tuesday, April 06, 2004 3:12 AM
> Subject: Re: [CPMD-list] Pseudopotentials and diferences in results
>
>
> > Dear Jim
> >
> > the problem is related to your input using MT pseudos
> > You probably want to use the Kleinman-Bylander form of
> > these pseudopotentials. However, not specifying anything
> > defaults in the current version to a Gauss-Hermite
> > integration using 0 points -> neglect of non-local part.
> >
> > I suggest you use
> > *C_MT_BLYP_2 Kleinman-Bylander
> >  LMAX=P
> >
> > for all elements with LMAX > S.
> > To get good numerical results you should also increase
> > the cutoff. 70-85 Ry for TM pseudos and 80-120 Ry
> > for the Goedecker pseudos.
> >
> > regards
> >
> > Juerg Hutter
> >
> >
> > ----------------------------------------------------------
> > Juerg Hutter                   Phone : ++41 1 635 4491
> > Physical Chemistry Institute   FAX   : ++41 1 635 6838
> > University of Zurich           E-mail: hutter at pci.unizh.ch
> > Winterthurerstrasse 190
> > CH-8057 Zurich, Switzerland
> > ----------------------------------------------------------
> >
> >
> > On Mon, 5 Apr 2004, Jim Kress wrote:
> >
> > > I'm using CPMD v3.7.2 on a small Linux cluster and am a novice in the
> > > application of the CPMD code.   I am a Computational Chemist by
> education
> > > and experience with quite a bit of experience working with pcGAMESS and
> > > similar Quantum Chemistry codes.
> > >
> > > To familiarize myself with the CPMD code and its applications I have
> been
> > > performing some single molecule calculations.  I recently tried some
> > > calculations where I used different pseudopotentials.  I got some rather
> (to
> > > me) strange looking results, i.e., for my molecule of interest (using
> the
> > > Goedecker pseudopotentials distributed with CPMD) I calculated a total
> > > energy of -54.265019 au.  However, using exactly the same input file but
> > > specifying the Trouiller-Martins pseudopotentials (also distributed with
> > > CPMD) I calculate a total energy of -85.349239 au.
> > >
> > > Is this to be expected or do I have a whopper of an error in my input?
> > >
> > > I've attached in input and output files for inspection.
> > >
> > > Any comments, suggestions, or explanations of why these results are
> observed
> > > would be greatly appreciated.
> > >
> > >
> > > Jim
> > >
> >
>
>
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