[Wien] Phase-Transition.

[David Pankhurst]

Dear Neerja,

I've been looking into this kind of thing recently. However, I'm not
experienced and the following is based on conversations and what little
literature I've read.  Experts: If I've misrepresented anything please let
me know.

You can use the Phonon package, available from K.Parlinski, with the Wien
code to calculate the phonon spectrum and from this calculate the lattice
entropy contribution to the free energy.  Does that answer your question?  
There are other codes, however, which use a perturbative method, rather
than direct calculation of the force constants, to calculate the phonon
dispersion which may be more suitable (i.e. faster) for your needs but
this is not available in Wien2k.

A question to the developers: Are there any plans to implement linear 
response in Wien2k?

best regards,

	Dave Pankhurst

On Wed, 19 Nov 2003, Neerja wrote:

> Dear All,
> I would like to know, if there is any phase transion, from which quantity
> (change in that qunatity) we can verify the phase transition.
> 
> I hope, you can understand my question. e.g. change in free energy or any
> other quantity, which we can calculate using WIEN2k and gives us an idea
> about phase transition.
> 
> With regards
> Neerja
> 
> +++++++++++++++++++++++++++++++++++++++
> Dr. Neerja			             
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| Dr David Pankhurst,             | Tel : +44 1865 283325/283326       |
| Department of Materials,        | Fax : +44 1865 273789              |    
| University of Oxford,           |                                    |
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