[Wien] temperature dependent DFT (band, ...) calculations

[Peter Blaha]

If you are lucky, yes, but in general, the answer is NO !!!

The lattice parameter is only a "mean value", and is a "prerequisite" 
for a finit temp calculation.

But think about: what means "Termperature"  ?

It vibrations, which are excited more or less with T. The atoms move 
around heavily and this can be even anisotropic.
And one measures basically an average of a certain quantity while the 
atoms are vibrating around.

Calculating phonons gives you entropy and free energies;
Doing properties with temperature dependent average displacements gives 
you properties at finite T.

One example: Physical Review B, 98 (2018), S. 235205.


Am 18.04.2020 um 15:33 schrieb Dr. K. C. Bhamu:
> Dear Experts,
> 
> Could you please confirm that if I have temperature dependent lattice 
> parameters, from DFT calculation, then whatever properties like band, 
> phonon, elastic, ... , I compute will be considered as temperature 
> dependent ?
> Yes, ionic positions should be relaxed what I know.
> My own answer would be yes for this query but I need a confirmation.
> 
> It would be a help from computational resources point of view. I do not 
> want to test the calculation and see the the difference as system is 
> more computational time demanding.
> 
> Thank you very much.
> 
> Regards
> Bhamu
> 
> 
> 
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