[Pw_forum] Dynamic polarizability of C60

[Axel Kohlmeyer]

On Tue, Jan 17, 2012 at 11:23 AM, anne etindele <annetindele at yahoo.fr> wrote:
> Dear all
>
> I am a new user of Quantum espresso (espresso-4.3.1), and I have found that
> it is possible,
> as it is done in example 33, to calculate dynamic polarizability of
> molecules using pw.x
> and ph.x.
>
> I am interested on the description of properties of C60 complex. I tried to
> modify the script of example 33
> in order to get its dynamic polarizability but I couldn't even run self
> consistent calculation as the code signals "MPI abort..".
>
> I would like to know if:
>
> it is possible to get dynamic polarizability or photoionization cross
> section of C60 using this method or with any other code
> it can run on normal desktop or laptop (Dual Core CPU with 4GB of RAM and
> 2.8 GHz) of frequency?

anne,

a C60 system is pretty large for a DFT calculation,
particularly, since you need to leave enough vacuum
space around it, to get the result for the isolated object.

this kind of calculation would require more than just a
laptop to be completed before the next ice age. you have
to factor in, that plane wave DFT calculations are not
scaling linearly with the system size (and not at all
with the number of electrons).

perhaps you should do your first independent calculations
with a less ambitious project. ;-)

salut,
    axel.

> there is an input file of C60 available in case if my in put file may be the
> problem
>
>
> The sample in put file I modified and used is joined to this mail.
>
> Kind regards
>
> Anne J. ETINDELE
> PhD Student
> Laboratoire de Physique Fondamentale
> Université de Douala, Cameroun
> Assistant Lecturer
> Ecole Normale Supérieure
> Université de Yaoundé, Cameroun
>
>
>
>
>
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-- 
Dr. Axel Kohlmeyer
akohlmey at gmail.com  http://goo.gl/1wk0

College of Science and Technology
Temple University, Philadelphia PA, USA.