[Pw_forum] phonon dispersion from IFC

[Stefano Baroni]

How would the dynamical matrices ever know that the lattice parameter has changed, if you do not recalculate them? Unless you have a model to predict the dependence of the IFCs upon pressure/latt param ... SB

--
Stefano Baroni, Trieste -- swift message written and sent on the go

On 13/set/2011, at 19:35, Claudio Perottoni <caperott at ucs.br> wrote:

> Hi,
> 
> I just finished a very lengthy calculation of the phonon dispersion 
> spectrum for a 132-atom structure using DFPT and interatomic force 
> constants. I wonder could the same IFCs be used to calculate the phonon 
> spectrum for the same compound, now optimized at a different pressure, 
> i.e., with different lattice parameters and atomic positions, without 
> the need to perform the full calculation of phonons and dynamical 
> matrices and generate new IFCs all over again ?
> 
> Thanks for your attention!
> 
> Regards,
> 
> Claudio
> 
> -- 
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> Dr. Cláudio A. Perottoni
> 
> Universidade de Caxias do Sul
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