[Pw_forum] Dynamic polarizability of C60

[anne etindele]

DearEduardo

You wanted to know What exactly this dynamical polarizability is?

In fact, when a system (atomic, molecule,...) is submitted to an external field, 
its electrons are reorganised according to the frequence of that external field. 
One can then evaluate the aptitude of the system to be subject to that reorganisation
by evaluating the polarizability. Particularly when the phenomenon is time dependent,
one evaluate the dynamical polarizability.
 
 is it include  the electronic , phonon or both contributions?
 
For my case, I want to consider C60 as a dielectric sphere of finite or infinite 
thickness, I don't know exactly if the phonon contribution is relevant, but I am 
mostly evolved in electronic calculations. 

 What are the frequency units (THz, eV? ) in the example 33.

 As I see in output of that example 33 (it is also the case for almost all the other 
input and output files of espresso-4.3.1), the energies and frequencies are in Ry


Kind regard 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20120124/3c2aa2f9/attachment.html>