[Wien] Calculations at moderate T

[Peter Blaha]

a) Simply empirically extrapolate a0 to a possible value at 1200 K.

b) Ab initio: quasiharmonic approximation.
    Calculate phonons (wien2k + ponon or phonopy, see u supported sw)
    and resulting -TS at various lattice parameters and
    search for the minimum of the free energy as function of a0
    at the desired T

Of course, for a surface this is more difficult. Of course one can use the
expanded a,b lattice constants, but relaxation of z will still corrsepond
to t=0. It is more a simulation of an epitactically expanded lattice.

Am 09.04.2013 19:38, schrieb Laurence Marks:
> Does anyone know of methods to do calculations at T~1200K taking
> account of bulk thermal expansion? I am interested in a surface
> calculation where I suspect that it may be important to consider this,
> and a moderately rational approach to doing this that has been
> tested/published would be useful.
>

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Peter Blaha
Inst. Materials Chemistry, TU Vienna
Getreidemarkt 9, A-1060 Vienna, Austria
Tel: +43-1-5880115671
Fax: +43-1-5880115698
email: pblaha at theochem.tuwien.ac.at
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