[Pw_forum] performance of occupation='fixed' and ='smearing'

[Gabriele Sclauzero]

shypirate wrote:
> Dear all:
> When I use pw.x, I find that performance of different occupations are 
> different. If I set occupation='smearing', it takes about 6 minutes for 
> one diagonalization step, but 24 minutes for occupation='fixed'. I have 
> set the same "nbnd" and "K_POINTS" for both. My question is, why is the 
> performance difference?

If it's like you say, the only possible difference that comes to my mind is in the number 
of iterations used in the Davidson algorithm for diagonalization (though I never thought 
it could depend on the occupations method). Please check for the keyword "iterations" 
(which is printed together with the number of iterations after each diagonalization step):
 > grep iterations yourfile
and let me know the output.

GS

> Best Wishes,
> Y.P.Wang
> 
> 
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