[Pw_forum] deguss

[Nicola Marzari]

yaldaa kh wrote:
> dear all
> 1) why does the total energy (Escf ) decrease with increase of the 
> deguss value in smearing technique?
> 2) How can I choose a good value (the best choise) for deguss?
>  
> thanks a lot
> yalda
> student (chemistry)
> 


1) It shouldn't for standard smearings (e.g. Fermi-Dirac, gaussian).
E-TS decreases. For m-p, m-v, we cannot say.

2) See Chap 4 of http://quasiamore.mit.edu/phd/ for plenty details.

			nicola


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Prof Nicola Marzari   Department of Materials Science and Engineering
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