[Pw_forum] TDDFT approach for periodic system

[Giuseppe Mattioli]

Dear all
I did not say that TDDFPT does not work with periodic system, but you cannot 
have a realistic absorption spectra of a slab (or bulk crystal) if you sample 
the Brillouin zone by using Gamma only... TDDFPT works fine with finite 
systems, i.e., which do not show a (strong) k dependence of the psi_n,k 
eigenvalues.

Giuseppe

On Wednesday 20 April 2011 03:00:41 Johari, Priya Sudhir wrote:
> Thanks Marton, its working.
>
> On Tue, Apr 19, 2011 at 5:40 PM, Marci <vormar at gmail.com> wrote:
> > Dear Priya,
> >
> > Though I have never tried, it should work with periodic systems if you
> > sample the Brillouin zone only with the gamma point. Keep in mind that
> > the usual adiabatic approximations with (semi)local functionals might
> > not work very well for calculating the absorption of periodic systems.
> >
> > Marton
> >
> > --
> > Marton Voros
> > PhD student
> > Department of Atomic Physics
> > Budapest University of Technology and Economics
> > Budafoki út 8., H-1111, Budapest, Hungary
> > www.fat.bme.hu/MartonVoros
> >
> > On Tue, Apr 19, 2011 at 11:02 PM, Johari, Priya Sudhir
> >
> > <priya_johari at brown.edu> wrote:
> > > Thanks Duy, but the link does not give sufficient information. However,
> > > I found a discussion on forum's archive itself where Giuseppe Mattioli
> > > has mentioned that TDDPFT does not work for periodic systems :-(
> > >
> > > Dr Priya Johari.
> > > Brown University,
> > > Providence, RI - 02906. USA
> > >
> > > On Tue, Apr 19, 2011 at 3:59 PM, Duy Le <ttduyle at gmail.com> wrote:
> > >> If you do a little homework (such as googling keyword TD-DFPT), you'll
> > >> find this link
> > >> http://qe-forge.org/projects/tddfpt/
> > >> I have not read it carefully but I guess it contains some useful
> > >> information.
> > >> --------------------------------------------------
> > >> Duy Le
> > >> PhD Student
> > >> Department of Physics
> > >> University of Central Florida.
> > >>
> > >> "Men don't need hand to do things"
> > >>
> > >>
> > >>
> > >> On Tue, Apr 19, 2011 at 3:26 PM, Johari, Priya Sudhir
> > >>
> > >> <priya_johari at brown.edu> wrote:
> > >> > TD-DFPT
> > >>
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   Giuseppe Mattioli                            
   CNR - ISTITUTO DI STRUTTURA DELLA MATERIA   
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