[CPMD-list] isolated molecule translation during dynamics

Yong Zhang zhangymall11 at gmail.com
Mon Jan 22 16:07:00 CET 2007


I gave an initial temperature of 300K.
I first run a traj with "tempcontrol" in order to equilibrate the system
somehow, then run NVE md restart from the last point.

"tempcontrol" input:
##############
&INFO
isolated NMA

  RESTART WAVEFUNCTION COORDINATES VELOCITIES ACCUMULATORS LATEST
&END

&CPMD
  MOLECULAR DYNAMICS BO
  RESTART WAVEFUNCTION COORDINATES LATEST
  CONVERGENCE ORBITALS
  1.0e-7

  REAL SPACE WFN KEEP SIZE
  256

  EXTRAPOLATE WFN
  3

  TEMPCONTROL IONS
  300.0 30.0

  TIMESTEP
  20.0

  MAXSTEP
  1000

  TRAJECTORY XYZ SAMPLE
  10

&END

&SYSTEM
  ANGSTROM
  SYMMETRY
  1
  CELL
  12.00  1.0  1.0  0  0  0
  CUTOFF
  90.0
&END

&DFT
  NEWCODE
  FUNCTIONAL PBE
  GC-CUTOFF
  5.0e-6
&END

&ATOMS

  ISOTOPE
   1.0
   2.0
   12.0
   14.0
   16.0
*H_MT_PBE.psp   KLEINMAN-BYLANDER
   LMAX=S
   6
   1.69080    .05583    .88430
   3.28199   -.14332    .06344
   2.16794  -1.45255    .00207
  -1.58359    .17630  -2.35128
   -.19701    .20889  -3.48962
   -.49100   1.60271  -2.37391

*H_MT_PBE.psp   KLEINMAN-BYLANDER
   LMAX=S
   1
   -.22859   -.88824   -.93883

*C_MT_PBE.psp   KLEINMAN-BYLANDER
   LMAX=P
   3
   2.18368   -.34882    .01350
   1.56123    .24388  -1.15711
   -.53752    .48601  -2.44731

*N_MT_PBE.psp   KLEINMAN-BYLANDER
   LMAX=P
   1
    .32592   -.14815  -1.44467


*O_MT_PBE.psp   KLEINMAN-BYLANDER
   LMAX=P
   1
   2.16429   1.09559  -1.77796

&END
##################

follwoing NVE runs
##################
&INFO
isolated NMA
&END

&CPMD
  MOLECULAR DYNAMICS BO
  RESTART WAVEFUNCTION COORDINATES VELOCITIES ACCUMULATORS LATEST

  CONVERGENCE ORBITALS
  1.0e-7

  REAL SPACE WFN KEEP SIZE
  256

  EXTRAPOLATE WFN
  3

  TEMPERATURE
  300.0

  TIMESTEP
  20.0

  MAXSTEP
  1000

  TRAJECTORY XYZ SAMPLE FORCES DCD
  2

  DIPOLE DYNAMICS SAMPLE WANNIER
  2
  WANNIER REFERENCE
  0.0 0.0 0.0
  WANNIER SERIAL

&END

&SYSTEM
  ANGSTROM
  SYMMETRY
  1
  CELL
  12.00  1.0  1.0  0  0  0
  CUTOFF
  90.0
&END

&DFT
  NEWCODE
  FUNCTIONAL PBE
  GC-CUTOFF
  5.0e-6
&END

&ATOMS

  ISOTOPE
   1.0
   2.0
   12.0
   14.0
   16.0
*H_MT_PBE.psp   KLEINMAN-BYLANDER
   LMAX=S
   6
   1.69080    .05583    .88430
   3.28199   -.14332    .06344
   2.16794  -1.45255    .00207
  -1.58359    .17630  -2.35128
   -.19701    .20889  -3.48962
   -.49100   1.60271  -2.37391

*H_MT_PBE.psp   KLEINMAN-BYLANDER
   LMAX=S
   1
   -.22859   -.88824   -.93883

*C_MT_PBE.psp   KLEINMAN-BYLANDER
   LMAX=P
   3
   2.18368   -.34882    .01350
   1.56123    .24388  -1.15711
   -.53752    .48601  -2.44731

*N_MT_PBE.psp   KLEINMAN-BYLANDER
   LMAX=P
   1
    .32592   -.14815  -1.44467


*O_MT_PBE.psp   KLEINMAN-BYLANDER
   LMAX=P
   1
   2.16429   1.09559  -1.77796

&END
#####################


On 1/22/07, Ari P Seitsonen <ari.p.seitsonen at iki.fi> wrote:
>
>
> Dear Yong,
>
>    How did you assign the initial velocities, by hand or by giving an
> initial temperature? Could you please also provide your input file, it
> seems very strange that the molecule would translate that much.
>
>      Greetings from Trieste,
>
>         apsi
>
>
> -=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-
>    Ari P Seitsonen / Ari.P.Seitsonen at iki.fi / http://www.iki.fi/~apsi/
>    IMPMC, CNRS & Université Pierre et Marie Curie
>    Tel: +33-1-4427 7542, Fax: +33-1-4427 3785, GSM: +33-6-6736 3820
>
> On Mon, 22 Jan 2007, Yong Zhang wrote:
>
> > Thanks for all these suggestions. I am testing the SUBTRACT keyword now.
> >
> > For the symmetry=0 or 1, the manual says, "for many systems using a
> large
> > enough cell and pbc is also an option. ...except in difficult cases such
> as
> > charged molecules..." and "the pbc calculation is always cheaper for a
> box
> > of the same size". Because I have a neutral molecule, I expect similar
> > results by using either symmetry=0 or 1. But, to be honest, I do not
> have
> > special reason to perfer one over the other. And actually, I do  not
> really
> > know the advange or disadvantage of one over the other one, especially
> for
> > my system. I appreciate if you or anyone can put more comments on this.
> >
> > Thanks.
> > Yong
> >
> >
> > On 1/22/07, Nisanth Nair <nisanth.nair at theochem.ruhr-uni-bochum.de>
> wrote:
> >>
> >> Hi
> >> One more thing; use also SYMMETRY 0 for isolated molecule. See more
> >> details in
> >> the manual.
> >> cheers,
> >> Nisanth
> >>
> >> On Sunday 21 January 2007 14:12, Juerg Hutter wrote:
> >> > Hi
> >> >
> >> > check the manual for the keywords
> >> >
> >> > SUBTRACT COMVEL
> >> > SUBTRACT ROTVEL
> >> >
> >> > regards
> >> >
> >> > Juerg Hutter
> >> >
> >> > ----------------------------------------------------------
> >> > Juerg Hutter                   Phone : ++41 44 635 4491
> >> > Physical Chemistry Institute   FAX   : ++41 44 635 6838
> >> > University of Zurich           E-mail: hutter at pci.unizh.ch
> >> > Winterthurerstrasse 190
> >> > CH-8057 Zurich, Switzerland
> >> > ----------------------------------------------------------
> >> >
> >> > On Sat, 20 Jan 2007, Yong Zhang wrote:
> >> > > Hi,
> >> > >
> >> > > I am running BOMD on a isolated, neutral, small molecule (with
> >> dimension
> >> > > < 5A). I used symmetry=1 with a "large enough cell" of 12A. No"
> NOSE"
> >> was
> >> > > used. I found the molecule translated a lot during the MD: the
> >> molecule
> >> > > was at the center of the box (0,0,0) in the beginning, but the
> >> > > coordinates changed to something like (-80, 95, -130) after a
> while,
> >> > > which is much larger than the box dimension. I checked the molecule
> >> > > structure, it seems ok. But will this cause any problem? Is there a
> >> way
> >> > > to remove this translation?
> >> > > Thanks
> >> > >
> >> > > Yong
> >> >
> >> > _______________________________________________
> >> > CPMD-list mailing list
> >> > CPMD-list at cpmd.org
> >> > http://cpmd.org/mailman/listinfo/cpmd-list
> >>
> >> --
> >>
> >>
> ===========================================================================
> >> Nisanth N. Nair
> >> Lehrstuhl fuer Theoretische Chemie   Tel: ++49 (0)234 32 22121
> >> Ruhr-Universitaet Bochum                Fax: ++49 (0)234 32 14045
> >> Universitaetstrasse 150
> >> D-44801 Bochum, Germany
> >> Email: nisanth.nair at theochem.ruhr-uni-bochum.de
> >> Web  : http://www.theochem.ruhr-uni-bochum.de
> >>
> >>
> ===========================================================================
> >>
> >
>
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