[CPMD-list] Where to find more examples?

[Weiqiao Deng]

Many thanks for your message. I checked your website. It is indeed helful.

Weiqiao

On Thu, 18 Mar 2004, Axel Kohlmeyer wrote:

> On Thu, 18 Mar 2004 13:13:52 -0800 (PST)  Weiqiao Deng wrote:
> 
> > Dear Axel,
> > 
> > 
> > Many thanks for your message.
> > I have one more question. 32-bulk water is a neutral system. If we have
> > extra OH- or H+ in the system, we set the charge as -1 or +1 for whole
> > system? Do we have a way to set the particle extra H's charge as +1?
> > Thanks.
> 
> you can only set the charge for the whole system
> (CHARGE keyword, &SYSTEM section). cpmd uses that
> information in combination with the (effective)
> charges of the atoms from the pseudopotential files
> to compute the total number of electrons in the system.
> 
> the actual charge distribution
> will be calculated, when you do the wavefunction
> optimization. please note that the keyword ATOMIC CHARGES
> (&ATOMS section) is only used to calculate the initial 
> guess for the electron structure and has no effect on
> the total number of electrons.
> 
> you may also have a look at
> <http://www.theochem.ruhr-uni-bochum.de/~axel.kohlmeyer/files/xyz2cpmd.pl>
> which might be helpful to contruct the &ATOMS and &SYSTEM section
> of for your simulations if you feed it an xyz-file with your pre-equlibrated
> restart. you may have to adapt it for your choice of pseudopotentials.
> 
> axel
> 
> > 
> > Weiqiao
> > 
> > 
> > On Thu, 18 Mar 2004, Axel Kohlmeyer wrote:
> > 
> > > On Wed, 17 Mar 2004, Weiqiao Deng wrote:
> > > 
> > > WD> Dear list,
> > > WD> 
> > > WD> I am a beginner to use CPMD and hope to find more examples to repeat and
> > > WD> learn CPMD simulation.
> > > WD> 
> > > WD> Here is the special example I am interested at repeating. Anyone has that
> > > WD> input file of that example? Thanks in advance.
> > > WD>  
> > > WD> Tuckerman ME, Marx D, Parrinello M
> > > WD> The nature and transport mechanism of hydrated hydroxide ions in aqueous
> > > WD> solution NATURE 417 (6892): 925-929 JUN 27 2002
> > > 
> > > dear weiqiao,
> > > 
> > > there is a 32-bulk water example in the cpmd-test archive,
> > > using MT pseudopotentials, you could use that as a starting point.
> > > 
> > > i suggest you first equilibrate a suitable configuration with
> > > a classical MD simulation (i found the SPC/E water potential 
> > > seems to yield structures, that are very close to the 
> > > CP-MD structures with the BLYP functional). this way you
> > > would have a comparatively short equilibration time
> > > for the CP-MD run (compared to, e.g. removing a hydrogen
> > > atom from a bulk water system). 
> > > 
> > > btw: don't forget to set the charge or you 
> > > will get very surprising results. <g>
> > > 
> > > good luck,
> > > 	axel.
> > > 
> > > WD> 
> > > WD> Weiqiao
> > > WD> 
> > > WD> _______________________________________________
> > > WD> CPMD-list mailing list
> > > WD> CPMD-list at cpmd.org
> > > WD> http://www.cpmd.org/mailman/listinfo/cpmd-list
> > > WD> 
> > > WD> 
> > > 
> > > 
> > 
> 
> --
> 
> =======================================================================
> Axel Kohlmeyer      e-mail:  axel.kohlmeyer at theochem.ruhr-uni-bochum.de
> Lehrstuhl fuer Theoretische Chemie          Phone: ++49 (0)234/32-26673
> Ruhr-Universitaet Bochum - NC 03/53         Fax:   ++49 (0)234/32-14045
> D-44780 Bochum                   http://www.theochem.ruhr-uni-bochum.de
> =======================================================================
> If you make something idiot-proof, the universe creates a better idiot.
>