Hi Chris,
I thought it could be necessary, but it's been some days I've tried to
subscribe and still have no answer, guess I'll have to wait a little longer
then.
Thanks,
Eric
2009/6/8 Christopher Rowan
> Hi Eric,
> You must sign up for a user account on the SIESTA website to access
> the pseudopotentials: this took a day or two for me. Then, once you
> log in, on your user menu on the left you will see an option for
> pseudos and bases.
> Regards,
> Chris
>
> 2009/6/8 Eric Perim :
> > Thanks for the helpful tutorial. But where is this Siesta pseudopotential
> > database you mention on it?
> >
> > Regards,
> > Eric
> >
> > 2009/6/4 Zhong-Li Liu
> >>
> >> Dear Andrei,
> >> Thank you for your kind reply, and I shall have some tests
> >> according your suggestion.
> >>
> >> Best regards,
> >>
> >> Zhongli
> >>
> >> On 04/06/2009, apost...@uni-osnabrueck.de
> >> wrote:
> >> >> Dear Andrei,
> >> >> You said in your SIESTA-tuto that the frozen phonon calculations
> >> >> usually
> >> >> proceed after CG relaxation.
> >> >
> >> > Dear Zhongli,
> >> > this is not obligatory, techniclly speaking, but any book on phonons
> >> > tells you how they are introduced from Taylor expansion arond
> >> > the equilibrium. So, this equilibrium first has to be found.
> >> > If your system does not have internal coordiates you don't have
> >> > to worry (say, for pure NaCl you can calculate phonons right away
> >> > for any lattice constant without a need to relax), but if the internal
> >> > cordinates are present (as say in wurtzite or rutile) - yes,
> >> > the relaxation in principle should be done first.
> >> > Oterwise, you have a chance to get imaginary modes
> >> > with eigenector pointing towards the relaxed
> >> > geometry, where the system would be able to lower its energy.
> >> >
> >> >> Is that means we should
> >> >> first set "MD.TypeOfRun CG" to relax
> >> >
> >> > yes
> >> >
> >> >> and then change it to "MD.TypeOfRun FC"
> >> >> with "UseSaveData T"
> >> >
> >> > yes
> >> >
> >> >> and "MD. UseSaveXV T" to calculate the force constants?
> >> >
> >> > No, in fact I suggested to copy the relaxed coordinates
> >> > into the .fdf file and then proceed phonons with
> >> > MD. UseSaveXV F
> >> > But it is just a suggestion.
> >> >
> >> > Best regards
> >> >
> >> > Andrei
> >> >
> >>
> >>
> >> --
> >> PhD. student of IAMP, Sichuan University, China
> >> E-mail: zl.liu.c...@gmail.com
> >
> >
> >
> > --
> > ==
> > Eric Perim Martins
> > Universidade Estadual de Campinas - UNICAMP
> > Instituto de Física Gleb Wataghin - IFGW
> > Grupo de Sólidos Orgânicos e Novos Materiais - GSONM
> > Departamento de Física Aplicada (DFA) - Sala 19
> > Campinas - São Paulo - Brasil
> > CEP 13083-970
> > Telefone: (19)3521-0289 - Ramal 10289
> > MSN: pe...@nextwave.com.br
> > ==
> >
>
--
==
Eric Perim Martins
Universidade Estadual de Campinas - UNICAMP
Instituto de Física Gleb Wataghin - IFGW
Grupo de Sólidos Orgânicos e Novos Materiais - GSONM
Departamento de Física Aplicada (DFA) - Sala 19
Campinas - São Paulo - Brasil
CEP 13083-970
Telefone: (19)3521-0289 - Ramal 10289
MSN: pe...@nextwave.com.br
==
