[CPMD-list] experienced problem

[Marie-Francoise POLITIS]

> > &CPMD
> >       OPTIMIZE WAVEFUNCTION/MOLECULAR DYNAMICS cp
> >       TIMESTEP
> >       4
> >       MAXSTEP
> >       500
> >      EMASS
> >      1100.
I agree with A Kohlmeyer EMASS=1100 is huge in view of a time step of 4
The standard is Timestep of 5 with EMASS of 600 , but depending of what
you are studying EMASS can  be smaller just have a look at the "Hutter"
CPMD tutorial Page 19 ("How to control adiabaticity"), you will understand
what is the real problem.
Moreover I do not understand why you put >
> >      TEMPERATURE ELECTRONS
> >      1000.0
Cheers
M-F Politis
> >
> >
> > ----- Original Message -----
> > From: "Ari P Seitsonen" <ari.p.seitsonen at iki.fi>
> > To: "liuzhim" <liuzhim at mail.jl.cn>
> > Cc: <cpmd-list at cpmd.org>
> > Sent: Sunday, December 16, 2007 10:17 PM
> > Subject: Re: [CPMD-list] HELP: Explaination to manual 9.5.2
> >
> >
> > >
> > >
> > > Dear Mme/Mlle/M Liu,
> > >
> > >   That sentence ONLY applies to calculations in the electronically excited
> > > state (employing TDDFT, that chapter is meant to be read only when using
> > > TDDFT). However, it is always preferable to perform an optimisation of the
> > > wave functions before a molecular dynamics run when running the
> > > Car-Parrinello MD, it is a common source of error to try start directly
> > > with the dynamics.
> > >
> > >     Greetings from Strasbourg,
> > >
> > >        apsi
> > >
> > > PS Which version of the code are you using?
> > >
> > > On Sun, 16 Dec 2007, liuzhim wrote:
> > >
> > >> Hi, every body:
> > >>   I have a question to the manual for CPMD, and hope somebody may give help.
> > >>    I want to handle some finete temperature simulations via CPMD.  All
> > >> the examles were tried. Recently, when I read the manual carefully, the
> > >> sentence  "geometry optimizations and molecular dynamics simulations can
> > >> only be performed after an electronic spectra calculation" in section
> > >> 9.5.2 makes me much confused. Does it mean that I should calculate the
> > >> electronic spectra even though I just want to perform a dynamical
> > >> simulation  to investigate the mechanical or thermal properties for ions
> > >> while the electronic properties are neglected? If I do not do the
> > >> spectra work, what will occur to the results?
> > >>                                                        Z. M. Liu from , Changchun, P.R.C
> > >>                                                         Dec. 16, 2007
> > >>                                                        liuzhim at mail.jl.cn
> > >>                                                                 .
> > >> _______________________________________________
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> > >> CPMD-list at cpmd.org
> > >> http://cpmd.org/mailman/listinfo/cpmd-list
> > >>
> > >
> > > --
> > > -=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-
> > >   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
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> >
>
>
> --
> =======================================================================
> Axel Kohlmeyer   akohlmey at cmm.chem.upenn.edu   http://www.cmm.upenn.edu
>   Center for Molecular Modeling   --   University of Pennsylvania
> Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
> tel: 1-215-898-1582,  fax: 1-215-573-6233,  office-tel: 1-215-898-5425
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> If you make something idiot-proof, the universe creates a better idiot.
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