[Pw_forum] phonon & temperature

[Paolo Giannozzi]

On Nov 14, 2009, at 3:56 , Mehrnaz Anvari wrote:

> I want to know what is the relation between phonon calculations
> and temperature? I know that density & external potentials depend
> on ion displacements, but I couldn't understand how does code
> connect these displacements to temperature?

the code doesn't connect anything to temperature. Phonon calculations
are performed at T=0. The Quasi-Harmonic Approximation allows to
calculate thermal properties at finite temperature.

> also I want to know that whether ionic displacements cause any ripples
> or roughness in the structure of sample or not?

what are you talking about?

---
Paolo Giannozzi, Dept of Physics, University of Udine
via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222