The ABINIT Users Mailing List ( CLOSED )

[Pawel Scharoch <scharoch@rainbow.if.pwr.wroc.pl>]

  Dear Don,

   thank you for your reply and advice.

   My experience with scanning the Potential Energy Surfaces
   "by hand"  is that when 'getxred' or 'getxcart' variables
   are used then the geometry can not be controlled from the
   *.in file any more. But it might be of a scientific interest
   sometimes to vary certain fixed geometrical parameters while
   allowing the other to relax, in the chain calculation.
   In that case the posiibility to store and read, from run
   to run, the relaxing geometrical parameters could, I think,
   significantly save the CPU time. I wrote abote this on Abinit
   forum some time ago
   (http://www.abinit.org/wws/arc/forum/2004-11/msg00011.html)

    With best regards,

     Pawel


On Wed, 4 May 2005, D. R. Hamann wrote:

> Dear Pawel,
>
> Try using the variable getxred or getxcart.
>
> Don Hamann
>
> Pawel Scharoch wrote:
>
> >   Dear all,
> >
> >    the Total Energy Surface seems to be a crucial idea in the
> >  'ab initio' structural investigations. It can be scanned
> >   "by hand" with the use of Abinit in multi-dataset mode.
> >   The "previous run" wave functions are used at every step,
> >   but a minor disadvantage is that the previously relaxed
> >   geometry is not accounted for, as it seems.
> >
> >    With best regards,
> >
> >    Pawel
> >
> >
> >
> >
> >
> > On Wed, 4 May 2005, NISHIMATSU Takeshi wrote:
> >
> > > Dear Dr. Rushchanskii,
> > >
> > > > I would like to ask you, are there any possibilities (or numerical
> > > > trics) to obtain a transition path using ABINIT?
> > >
> > >
> > > Methods of determination of transition path (or chemical reaction path)
> > > implemented in Gaussian is briefly described in
> > > "Geometry Optimization on Potential Energy Surfaces"
> > > by H. Bernhard Schlegel in Modern Electronic Structure Theory, Part I,
> > > edited by D. R. Yarkony (World Scientific, Singapore, 1995) Chap. 8.
> > >
> > > We hacked Src_9drive/brdmin.f and implemented it in easy
> > > (or approximated) way. Please check our article:
> > > T. Hashimoto, T. Nishimatsu, H. Mizuseki, Y. Kawazoe, A Sasaki na Y Ikeda.
> > > "Ab initio determination of total-energy surfaces for distortions of
> > > ferroelectric perovskite oxides"
> > > Jpn. J. Appl. Phys. vol.43 (2004) pp.6785-6792
> > >
> > > Sincerely,
> > > --
> > > love && peace && free_software
> > > NISHIMATSU Takeshi
>
>
> --
> D. R. Hamann                            Phone: 908-582-4454
> Director, Theoretical Materials         Fax:   908-582-4868
> Physics Research (retired)              email: drh@physics.bell-labs.com
> Bell Laboratories Lucent Technologies
> 700 Mountain Ave, Room 1D-371
> Murray Hill, NJ 07974-0636 USA